[Federal Register Volume 90, Number 2 (Friday, January 3, 2025)]
[Rules and Regulations]
[Pages 390-468]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2024-30340]
[[Page 389]]
Vol. 90
Friday,
No. 2
January 3, 2025
Part II
Department of Transportation
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National Highway Traffic Safety Administration
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49 CFR Part 571
Federal Motor Vehicle Safety Standards; Occupant Crash Protection, Seat
Belt Reminder Systems, Controls and Displays; Final Rule
Federal Register / Vol. 90 , No. 2 / Friday, January 3, 2025 / Rules
and Regulations
[[Page 390]]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2024-0071]
RIN 2127-AL37
Federal Motor Vehicle Safety Standards; Occupant Crash
Protection, Seat Belt Reminder Systems, Controls and Displays
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule.
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SUMMARY: This document amends Federal Motor Vehicle Safety Standard
(FMVSS) No. 208, ``Occupant crash protection,'' to require a seat belt
use warning system for rear seats. The rule also updates and enhances
the current seat belt warning requirements for the driver's seat belt
and extends these requirements to the front outboard passenger seat.
The final rule applies (with some exceptions) to passenger cars,
trucks, most buses, and multipurpose passenger vehicles with a gross
vehicle weight rating of 4,536 kilograms (10,000 pounds) or less. This
document also makes related amendments to FMVSS No. 101, ``Controls and
displays.''
DATES: Effective date: The effective date of this final rule is March
4, 2025.
Compliance date: The compliance date of this final rule is
September 1, 2026, for the front seat belt warning system requirements
and September 1, 2027, for the rear seat belt warning system
requirements, with optional early compliance permitted. Multi-stage
manufacturers and alterers would have an additional year to comply.
Petitions for reconsideration: Petitions for reconsideration of
this final rule must be received not later than February 18, 2025.
ADDRESSES: Petitions for reconsideration of this final rule must refer
to the docket and notice number set forth above and be submitted to the
Administrator, National Highway Traffic Safety Administration, 1200 New
Jersey Avenue SE, Washington, DC 20590. Note that all petitions
received will be posted without change to www.regulations.gov,
including any personal information provided.
Privacy Act: Petitions will be placed in the docket. Anyone is able
to search the electronic form of all documents received into any of our
dockets by the name of the individual submitting the comment (or
signing the comment, if submitted on behalf of an association,
business, labor union, etc.). You may review DOT's complete Privacy Act
Statement in the Federal Register published on April 11, 2000 (Volume
65, Number 70; Pages 19477-78) or you may visit https://www.transportation.gov/individuals/privacy/privacy-act-system-records-notices.
FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may contact
Ms. Carla Rush, Office of Crashworthiness Standards, Telephone: (202)
366-4583; Email: [email protected]; Facsimile: (202) 493-2739. For
legal issues, you may contact Mr. John Piazza ([email protected]) or
Eli Wachtel ([email protected]), Office of Chief Counsel, Telephone:
(202) 366-2992; Facsimile: (202) 366-3820. The address of these
officials is: the National Highway Traffic Safety Administration, 1200
New Jersey Avenue SE, Washington, DC, 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
II. Background
III. Other Seat Belt Reminder Requirements and Protocols
IV. Statutory Authority
V. Summary of the NPRM
VI. Final Rule and Response to Comments
A. Rear Seat Belt Warning Requirements
1. Applicability
2. Requirements
a. Visual Warning on Vehicle Start-Up
i. Type of Information Conveyed by the Visual Warning and
Whether Occupant Detection Should Be Required
ii. Lack of an Audible Warning
iii. Triggering Conditions for Start-of-Trip Warning (Not
Including Occupant Detection Criteria)
iv. Seat Occupancy Criteria and Interaction With Child Restraint
Systems
v. Duration
vi. Other Aspects
b. Audio-Visual Change-of-Status Warning
c. Electrical Connections/Removable Seats
d. Owner's Manual Instructions
e. Telltale Location
3. Alternative Warning Signals
B. Front Seat Belt Warning Requirements
1. Applicability
2. Driver's Seat Belt Warning for Light Buses
3. Visual and Audible Warning Duration and Activation
4. Visibility of Visual Warning for Front Outboard Passenger
Seat Belt
5. Front Seat Occupant Detection and Seat Occupancy Criteria
C. Issues Common to the Front and Rear Seat Belt Warning
Requirements
1. Modification of Start-of-Trip Warning Trigger Related
Ignition Switch Position To Accommodate EVs
2. Belt Use Criteria
3. Visual Warning Characteristics
4. Interaction With Other Vehicle Warnings
5. Audible Warning Characteristics (Other Than Duration)
6. Warning Deactivation and Acknowledgement and Hardening
7. Vehicles With Automated Driving Systems
8. Test Procedures
VII. Regulatory Alternatives
VIII. Overview of Benefits and Costs
A. Final Rule Requirements
1. Rear Seat Belt Warning System
2. Front Seat Belt Warning System
3. Overall Benefits and Costs of the Final Rule
B. Regulatory Alternatives
1. Occupant Detection in Rear Seats
2. 90-Second Front Outboard Seat Belt Warning
3. Seat Belt Warning for Front Center Seat
IX. Compliance Dates
X. Regulatory Analyses
Appendix A. List of Comments Cited in Preamble
I. Executive Summary
This final rule amends Federal Motor Vehicle Safety Standard (FMVSS
or Standard) No. 208, ``Occupant crash protection,'' to require a seat
belt use warning system for rear seats. This rule completes NHTSA's
response to a mandate in the Moving Ahead for Progress in the 21st
Century Act (MAP-21) that directed NHTSA to initiate a rulemaking to
require a seat belt warning for the rear seats in motor vehicles; it
also completes NHTSA's action on a rulemaking petition from Public
Citizen and Advocates for Highway and Auto Safety for the same rule.
The final rule also updates and enhances the current seat belt warning
requirements for the driver's seat belt and extends these requirements
to the front outboard passenger seat. The final rule applies (with some
exceptions) to passenger cars, trucks, most buses, and multipurpose
passenger vehicles (MPVs) with a gross vehicle weight rating (GVWR) of
4,536 kilograms (10,000 pounds) or less. NHTSA is issuing this final
rule under the National Traffic and Motor Vehicle Safety Act (Safety
Act), 49 U.S.C. chapter 301, Motor Vehicle Safety (49 U.S.C. 30101 et
seq.).
Safety Need for the Final Rule
Using a seat belt is one of the most effective ways a motor vehicle
occupant can prevent death and injury in a crash. Seat belts prevent
occupants from being ejected from the vehicle, provide ``ride-down'' by
gradually decelerating the occupant as the vehicle deforms and absorbs
energy, and reduce occupant contact with harmful interior surfaces and
other occupants. Seat belts are effective in most types of crashes and
[[Page 391]]
greatly reduce the risk of fatal and non-fatal injuries compared to the
risk faced by unrestrained occupants.
While seat belt use is meaningfully higher than it was a decade
ago, there is room for improvement. Usage rates for seat belts in rear
seats have consistently been below those for the front seats; and while
front seat belt use rates increased in the early 2010s, for the last
several years they have plateaued. According to data from NHTSA's
annual study of observed seat belt use, in every year from 2013 through
2022, seat belt use was lower in the rear seats than in the front
seats, ranging from a difference of about 9 percentage points in 2013
(78 percent vs. 87 percent) to about 14 percentage points in 2017 (75
percent vs. 89 percent). In 2022, front seat belt use was about 91.6
percent and rear seat belt use was about 81.7 percent.
Every year, thousands of unrestrained motor vehicle occupants are
killed in crashes and tens of thousands of unrestrained occupants are
injured (additional details on the target population are provided in
the summary of benefits and costs later in this executive summary).
Seat belt warning systems (also referred to as seat belt reminder
systems) encourage seat belt use by reminding unbuckled occupants to
fasten their belts and/or by informing the driver that a passenger is
unbelted so that the driver can request the unbelted occupant to buckle
up. The warnings provided by seat belt warning systems typically
consist of visual and/or audible signals. Research by NHTSA and others
shows that seat belt warning systems are effective at getting unbuckled
occupants to fasten their seat belts.
FMVSS No. 208 currently requires a short-duration audio-visual seat
belt warning for the driver's seat belt in passenger cars, most trucks
and MPVs with a GVWR of 4,536 kg (10,000 lb) or less, and buses with a
GVWR of 3,855 kg (8,500 lb) or less. Under these current requirements,
the visual component of the warning generally must be at least 60
seconds long, and the audible component must be at least four seconds
long.
Voluntary adoption by vehicle manufacturers of warnings that go
beyond this regulatory minimum, while considerable, has been mixed.
Although the regulations do not require seat belt warnings for any
seating position other than the driver's seat, almost all model year
(MY) 2022 vehicles have a voluntarily provided seat belt warning for
the front outboard passenger seat. However, voluntary adoption for rear
seats has been much slower, as only about 47 percent of MY 2022
vehicles come equipped with a voluntarily provided rear seat belt
warning system. Most vehicles already provide a seat belt warning for
both front outboard seats that is much longer than the minimal required
warning for the driver's seat belt, with the vast majority of vehicles
including an alert that is at least 90 seconds. This widespread
adoption suggests that the front seat belt warning minimum requirements
in the FMVSS are outdated, as consumers accept audio-visual reminders
that are far longer than the required minimums.
As discussed above, rear seat belt use rates have persistently been
below those for the front seats, and progress on front seat belt use
rates has slowed. Moreover, unbuckled occupants, in the front and rear
seats, continue to be overrepresented in fatal crashes (51 percent),
given the lower exposure of unbelted occupants relative to belted
occupants (because front seat belt use is about 90 percent and rear
seat belt use is 80 percent). Despite the effectiveness of seat belts
and seat belt warnings, most new vehicles continue to lack a rear seat
belt warning. Additionally, while most vehicles provide some level of
enhanced reminders for the front seats, this level of enhanced
protection has not occurred for all vehicles and is not standardized.
This gap in protection suggests a need for a beneficial safety
technology that is not being met in the vehicle market. This final rule
is intended to meet this safety need.
Legal Authority and Prior Regulatory History
NHTSA is issuing this final rule pursuant to the National Traffic
and Motor Vehicle Safety Act (49 U.S.C. 30101 et seq.) (Safety Act),
which authorizes NHTSA to establish FMVSSs. That statute requires
safety standards to be objective, practicable, and meet the need for
safety, among other things. NHTSA has concluded that the finalized
requirements satisfy these statutory criteria.
This final rule completes NHTSA's response to a rulemaking mandate
in MAP-21. MAP-21 required DOT (NHTSA, by delegation) to initiate a
rulemaking proceeding to require rear seat belt warnings and directed
the agency to issue a final rule unless the rule would not meet the
Safety Act requirements for an FMVSS.
This final rule also completes NHTSA's action on a rulemaking
petition from Public Citizen and Advocates for Highway and Auto Safety.
The petition requested that NHTSA issue a rule requiring a seat belt
warning system for rear seats on passenger cars and MPVs with a GVWR of
4,536 kg (10,000 lb) or less.
Summary of the Final Rule
This final rule amends the existing seat belt warning provisions in
FMVSS No. 208. The final rule has two main components. The first
requires a seat belt warning for the rear seats. The second amends and
enhances the seat belt warning requirements for the front outboard
seats. The requirements apply (with some exceptions) to passenger cars
and trucks, most buses, and multipurpose passenger vehicles with a GVWR
of 4,536 kg (10,000 lb) or less.
1. Rear Seat Belt Reminder Requirements
The first component of this final rule is a set of requirements for
a seat belt warning for rear seats. The new requirements have four main
elements.
Visual warning on vehicle start-up to inform the driver of
the status of the rear seat belts. The final rule requires a visual
warning that informs the driver how many or which rear seat belts are
in use and/or not in use. The warning must activate when the ignition
(or, for electric vehicles (EVs), propulsion system) is activated, and
last for at least 60 seconds. No visual warning is required if the
system can determine that there are no occupied rear seats or if there
are no occupied rear seats with a seat belt that is not in use.
Audio-visual change-of-status warning. The final rule
requires an audio-visual warning whenever a fastened rear seat belt is
unfastened while the vehicle is in forward or reverse drive mode. (The
warning is not required if the system can determine that a rear
passenger has unfastened the seat belt in order to exit the vehicle or
switch seats.) The warning must last for at least 30 seconds or until
the seat belt that triggered the warning is re-fastened. The audible
portion of the warning may be temporarily paused to allow another
audible safety warning alerting the driver to take immediate action.
Requirements related to electrical connections. Readily
removable rear seats must either automatically establish the electrical
connections when the seat is put in place or, if a manual connection is
required, the connectors must be readily accessible. Vehicles equipped
with certain types of seat belt warning systems are additionally
required to provide a visual warning to the driver if a proper
electrical connection has not been established.
Owner's manual requirements. The vehicle owner's manual
(which includes information provided by the vehicle manufacturer to the
consumer, whether
[[Page 392]]
in digital or printed form) must describe the warning system's
features, including the location and format of the visual warnings. It
must also include instructions on how to make any manual electrical
connections for readily removable seats.
2. Front Outboard Seat Belt Warning Requirements
The final rule includes several changes and enhancements to the
seat belt warning requirements for the front outboard seats. The new
requirements have two main elements.
Seat belt warning now required for front outboard
passenger seat. This final rule requires a seat belt warning for the
front outboard passenger seat. It does not require one for front center
seats because, among other things, doing so would not be cost-
effective. Currently, only the driver's seat is required to have a seat
belt warning, although almost all vehicles now provide a seat belt
warning for the front outboard passenger seat as well.
Enhanced audio-visual seat belt warning. The final rule
requires a longer-duration audio-visual warning than is currently
required for the driver's seat belt. The final requirements for this
warning differ from the proposal, which would have required (with some
exceptions) an audio-visual warning lasting until the belt at any
occupied front outboard seat was fastened. This included a warning at
the start of a trip and if a belt was unfastened during a trip. The
proposal did not include any other warning triggers, such as vehicle
speed. The final rule requires a visual warning and a two-phase audible
warning that is based, in part, on vehicle speed.
Visual warning. Under the final rule, a visual warning is required
whenever the ignition switch is in the ``on'' or ``start'' position (or
the propulsion system is activated), the seat is occupied, and the seat
belt is not in use. The warning must be visible to the driver.
Audible warning. The final rule requires a two-phase audible
warning. The first phase warning must activate when the ignition/
propulsion system is activated, the seat is occupied, and the belt is
not in use. The first phase warning must last for at least 30 seconds,
unless the seat belt that triggered the warning is fastened or the
second phase audible warning is activated within that time. The second
phase audible warning must activate, and remain active, whenever the
seat is occupied, the seat belt is not in use, and the vehicle speed is
at least 10 km/h (6.2 mph). The audible warning may be temporarily
paused to allow another audible safety warning alerting the driver to
take immediate action.
The final rule also contains requirements for the visual and
audible warnings as well as for other system features.
Compliance Date
This final rule establishes a compliance date for the amendments to
FMVSS No. 208, ``Occupant crash protection,'' as follows. Manufacturers
must comply with the amendments as of September 1, 2026 for the front
seat belt warning system requirements and September 1, 2027 for the
rear seat belt warning system requirements, with optional early
compliance (see Section IX for details). Consistent with 49 CFR
571.8(b), multi-stage manufacturers and alterers have an additional
year to comply.
Regulatory Alternatives
NHTSA considered a wide range of alternatives to the proposed
requirements. The main alternatives NHTSA considered were the seat belt
warning requirements in Economic Commission for Europe (ECE) Regulation
No. 16 (R16) and Euro New Car Assessment Programme (Euro NCAP). The
finalized requirements are identical or similar to ECE R16 and Euro
NCAP in many respects but differ from them in several ways. For
instance, while under ECE R16 the smallest occupant a rear seat belt
system with occupant detection must be capable of detecting is a small-
statured adult female, under the final rule such systems must be
capable of detecting occupants as small as a 6-year-old child and
activating the warning accordingly. Another way the proposal differs
from ECE R16 is the duration of the front seat belt warning on vehicle
start-up: R16 generally requires only a 30-60 second audio-visual
warning; the final rule requires, under certain conditions, an audio-
visual warning that lasts until the seat belt is buckled. The final
regulatory analysis quantifies the costs and benefits of three specific
regulatory alternatives: requiring occupant detection for the rear seat
belt warning system; requiring (for the front outboard seats) an audio-
visual warning on vehicle start-up with a duration of 90 seconds; and
requiring a seat belt warning for front center seats.
Benefits and Costs of the Proposed Requirements
This final rule is significant and was reviewed by the Office of
Management and Budget under Executive Order 12866, as amended by
Executive Order 14094.
NHTSA estimates the target population and the benefits and costs of
the final rule requirements in the stand-alone final regulatory impact
analysis (FRIA) that is being placed in the docket with this final rule
and is summarized in this document.
Based on NHTSA's data on fatalities and injuries from motor vehicle
crashes, adjusted to account for the benefits of other mandatory safety
technologies, there are, on average, 822 fatalities and 11,409 injuries
to unrestrained rear seat occupants and 8,383 fatalities and 154,739
injuries to unrestrained front outboard seat occupants each year. The
final rule requirements are aimed at reducing these deaths and
injuries.
NHTSA estimates the benefits it expects from the final rule seat
belt warning requirements. The benefits are the fatalities and injuries
that would be prevented by these requirements. The benefits depend,
principally, on the expected increase in seat belt use and the
effectiveness of seat belts in preventing deaths and injuries.
For the rear seat belt warning system analysis, NHTSA used a
``low'' and a ``high'' estimate for the increase in rear belt use with
the warning system. For occupants 11 years and older, these were 3 and
5 percentage points, respectively, and for occupants from 6 to 10 years
old, 0.3 and 0.4 percentage points respectively.\1\ For simplicity,
NHTSA refers to these scenarios as ``Low'' and ``High.'' The estimated
annual benefits for rear seat belt warning systems are presented in
table 1.\2\
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\1\ Children in booster seats are part of the target population
for this final rule because they should be restrained with the seat
belt and so would benefit from a seat belt reminder. The transition
to a booster seat typically occurs from ages 4-7 years, and
recommendations to remain in a booster seat exist until age 12
years.https://www.nhtsa.gov/vehicle-safety/car-seats-and-booster-seats#find-the-right-car-seat-car-seat-recommendations.
\2\ The Abbreviated Injury Scale (AIS) is a classification
system for assessing impact injury severity developed and published
by the Association for the Advancement of Automotive Medicine and is
used for coding single injuries, assessing multiple injuries, or for
assessing cumulative effects of more than one injury. MAIS
represents the maximum injury severity of an occupant at an AIS
level, i.e., the highest single AIS for a person with one or more
injuries. MAIS 1 & 2 injuries are considered minor injuries and MAIS
3-5 are considered serious injuries.
[[Page 393]]
Table 1--Estimated Annual Benefits--Potential Lives Saved and Injuries
Prevented for Rear Seat Belt Warning Systems (SBWS) Without Occupant
Detection, With Estimated ``Low'' and ``High'' Percentage Point Increase
in Belt Use
------------------------------------------------------------------------
Injury level Low High
------------------------------------------------------------------------
MAIS 1.................................. 36 54
MAIS 2.................................. 80 120
MAIS 3.................................. 26 38
MAIS 4.................................. 4 6
MAIS 5.................................. 1 2
-------------------------------
Total Injuries...................... 148 221
------------------------------------------------------------------------
Fatal................................... 26 39
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Another way to measure benefits is by calculating equivalent lives
saved (ELS). Equivalent lives saved are the number of prevented
fatalities added to the number of prevented injuries, with the
prevented injuries expressed in terms of fatalities (that is, with an
injury expressed as a fraction of a fatality, so that the more serious
the injury, the higher the fraction). The estimated equivalent lives
saved assuming either a 3 percent or 7 percent discount rate are
presented in table 2.
Table 2--Estimated Annual Benefits--Equivalent Lives Saved (ELS)--Rear
SBWS Without Occupant Detection
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3 Percent 7 Percent
Belt use increase discount rate discount rate
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Low................................... 29.98 24.31
High.................................. 45.09 36.55
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NHTSA also estimates the costs of the final rule requirements for
rear seat belt warnings. NHTSA estimates that the minimum cost to
comply with the rear seat belt warning requirements is $166.44 million
(M). This is based on a per-vehicle cost of $19.59 for 53.1 percent of
16M affected new vehicles.
Based on the foregoing, NHTSA performed benefit-cost and cost-
effectiveness analyses. A benefit-cost analysis calculates the net
benefits, which is the difference between the benefits flowing from
injury and fatality reductions and the cost of the rule. The net
benefit estimates are presented in table 3. The cost-effectiveness
analysis derives the cost per equivalent life saved, which is equal to
the total cost of the rule divided by the total fatal equivalents that
it prevents. These estimates are presented in table 4.
Table 3--Net Benefits--Rear SBWS Without Occupant Detection
[2020 Dollars, in millions]
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Benefits 3 Benefits 7 Net benefits 3 Net benefits 7
Belt use increase percent percent Cost percent percent
discount discount discount rate discount rate
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Low................................ $357.78 $290.05 $166.4 $191.34 $123.62
High............................... 538.00 436.16 166.4 371.56 269.72
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Table 4--Cost-Effectiveness Analysis (Cost per Equivalent Life Saved)--Rear SBWS Without Occupant Detection
[2020 Dollars, in Millions]
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ELS 3 ELS 7 Cost/ELS 3 Cost/ELS 7
Belt use increase percent percent Cost percent percent
discount discount discount discount
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Low...................................... 29.98 24.31 $166.4 $5.55 $6.85
High..................................... 45.09 36.55 166.4 3.69 4.55
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This final rule also enhances the driver seat belt warning
requirements by requiring an indefinite visual warning and a two-phase
audible warning that is based, in part, on vehicle speed that remains
active until the driver's seat belt is buckled and extending these
enhanced driver's seat belt warning requirements to the front outboard
passenger seat. NHTSA estimates the annual benefits of a seat belt
warning for the driver and outboard front passenger that remains active
until the occupant's seat belt is buckled as shown in table 5 and table
6.
[[Page 394]]
Table 5--Estimated Annual Benefits--Lives Saved and Injuries Prevented--Indefinite Duration SBWS (Front Outboard
Seats)
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Front
Injury level Driver passenger Total
----------------------------------------------------------------------------------------------------------------
MAIS 1.......................................................... 129 14 143
MAIS 2.......................................................... 151 19 170
MAIS 3.......................................................... 62 8 69
MAIS 4.......................................................... 9 1 10
MAIS 5.......................................................... 3 0 3
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Total Injuries.............................................. 354 42 395
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Fatal........................................................... 20 2 22
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Table 6--Estimated Annual Benefits--Equivalent Lives Saved--Indefinite Duration SBWS (Front Outboard Seats)
----------------------------------------------------------------------------------------------------------------
3 Percent 7 Percent
Undiscounted discount rate discount rate
----------------------------------------------------------------------------------------------------------------
Driver........................................................ 42.26 34.98 28.36
Front Passenger............................................... 4.44 3.68 2.99
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Total..................................................... 46.70 38.66 31.35
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NHTSA estimates that the incremental cost of the enhanced seat belt
warning for the driver's seat and the front outboard passenger seat
would be no greater than the currently available seat belt warning.
Although a seat belt warning is currently not required for the front
outboard passenger seats, we estimate that 96 percent of new vehicles
are equipped with them.\3\ NHTSA estimates that the cost for equipping
a front outboard passenger seat with a seat belt warning system is
about $2.13 per vehicle. To equip a seat belt warning system in the
front outboard passenger seat positions on the remaining four percent
of the new vehicle fleet (16 million) without such a warning is $1.36
million (= $2.13 x 0.04 x 16 million).
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\3\ Based on data on total projected vehicle sales in the United
States for MY 2022 from the agency's New Car Assessment Program
Purchasing with Safety in Mind: What to Look For When Buying a
Vehicle program.
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The total monetized benefits, costs, and net benefits (total
monetized benefits--total cost) of the enhanced seat belt warning
system for the driver and front passenger are shown in table 7. Table 8
presents the results of the cost effectiveness analysis--cost per
equivalent lives saved from enhanced SBWS for the driver and front
outboard passenger.
Table 7--Annual Monetized Benefits, Costs, and Net Benefits--Indefinite SBWS (Front Outboard Seats)
[2020 Dollars, in Millions]
----------------------------------------------------------------------------------------------------------------
Driver Front passenger Driver and front
---------------------------------------------------- passenger
-------------------------
3 Percent 7 Percent 3 Percent 7 Percent 3 Percent 7 Percent
----------------------------------------------------------------------------------------------------------------
Passenger Car Benefits............ $188.89 $154.12 $22.86 $18.65 $211.75 $172.77
Light Truck & Van Benefits........ 228.51 184.29 21.05 16.97 249.56 201.26
-----------------------------------------------------------------------------
Total Benefits................ 417.41 338.41 43.90 35.62 461.31 374.03
Total Costs................... 0 0 1.36 1.36 1.36 1.36
----------------------------------------------------------------------------------------------------------------
Net Benefits...................... 417.41 338.41 42.54 34.26 459.95 372.67
----------------------------------------------------------------------------------------------------------------
Table 8--Cost-Effectiveness Analysis (Cost per Equivalent Life Saved)--Indefinite SBWS (Front Outboard Seats)
[2020 Dollars, in millions]
----------------------------------------------------------------------------------------------------------------
Discount rate ELS Cost Cost/ELS
----------------------------------------------------------------------------------------------------------------
3 percent....................................................... 38.66 $1.36 $0.04
7 percent....................................................... 31.35 1.36 0.04
----------------------------------------------------------------------------------------------------------------
The net benefits of the final rule requiring seat belt warning for
rear seating positions and the enhanced seat belt warning for the front
outboard seats are shown in table 9. The net benefits are positive for
both 3 percent and 7
[[Page 395]]
percent discount rates and for both the low and high effectiveness
estimates for rear seat SBWS.
Table 9--Net Benefits From the Final Rule (SBWS Without Occupant
Detection for Rear Seating Positions and Indefinite SBWS for Front
Outboard Seating Positions)
[2020 Dollars, in millions]
------------------------------------------------------------------------
3 Percent 7 Percent
discount rate discount rate
------------------------------------------------------------------------
Front Outboard Seats.................... $459.95 $372.67
Rear Seats (low increase in rear seat 191.34 123.62
belt use)..............................
Rear Seats (high increase in rear seat 371.56 269.72
belt use)..............................
-------------------------------
Total Net Benefits (low increase in 651.29 496.28
rear belt use).....................
Total Net Benefits (high increase in 831.51 642.39
rear belt use).....................
------------------------------------------------------------------------
II. Background
On September 7, 2023, NHTSA published a notice of proposed
rulemaking (NPRM) to amend FMVSS No. 208, ``Occupant crash
protection,'' to require a seat belt use warning system for rear seats
and to enhance the existing front seat belt warning requirements,
including requiring a seat belt warning for the front outboard
passenger seat and increasing the duration of the warning.\4\ This
section provides an abbreviated background on the subject matter and
regulatory history of the proposed requirements. For a fuller
discussion, the reader is referred to the NPRM.\5\
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\4\ 88 FR 61674.
\5\ Id. at pgs. 61680-61686.
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Seat Belts and Seat Belt Warning Systems
Using a seat belt is one of the most effective actions a motor
vehicle occupant can take to prevent death and injury in a crash.\6\
Seat belts protect occupants in various ways. They prevent occupants
from being ejected from the vehicle, gradually decelerate the occupant
as the vehicle deforms and absorbs energy, and reduce the occurrence of
occupant contact with harmful interior surfaces and other occupants.\7\
Research has found that seat belts greatly reduce the risk of fatal and
non-fatal injuries compared to the risk faced by unrestrained
occupants. For rear seat occupants, seat belts reduce the risk of
fatality by 55 percent (for passenger cars) and 74 percent (for light
trucks and vans). For drivers, seat belts reduce the risk of fatality
by 48 percent (for passenger cars) and 61 percent (for light trucks and
vans) and reduce the risk of moderate to greater severity injuries by
65 percent. For front outboard passengers, seat belts reduce the risk
of fatality by 37 percent (for passenger cars) and by 58 percent (for
light trucks and vans) and reduce the risk of moderate to greater
severity injuries by 65 percent.\8\
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\6\ See, e.g., 68 FR 46262 (Aug. 5, 2003). See also Buckling Up:
Technologies to Increase Seat Belt Use. Special Report 278 at 18,
Committee for the Safety Belt Technology Study, Transportation
Research Board of The National Academies (2003).
\7\ Charles J. Kahane, Lives Saved by Vehicle Safety
Technologies and Associated Federal Motor Vehicle Safety Standards,
1960 to 2012--Passenger Cars and LTVs--With Reviews of 26 FMVSS and
the Effectiveness of Their Associated Safety Technologies in
Reducing Fatalities, Injuries, and Crashes. 89 DOT HS 812 069 at 89,
Department of Transportation, National Highway Traffic Safety
Administration (2015).
\8\ See the Final Regulatory Impact Analysis (FRIA) (in the
docket for this rulemaking) for these effectiveness estimates.
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While seat belt use is meaningfully higher than it was a decade
ago, there is room for improvement. Usage rates for rear seat belts
have consistently been below those for the front seats, and while front
seat belt use rates increased early in the previous decade, for the
last several years they have plateaued. According to data from NHTSA's
National Occupant Protection Use Survey (NOPUS), from 2013 to 2022,
seat belt use was lower in the rear seat than in the front seat,
ranging from a difference of 8.8 percentage points in 2013 (78.3
percent vs. 87.1 percent) to 14.3 percentage points in 2017 (75.4
percent vs. 89.7 percent).\9\ In 2022, front seat belt use was 91.6
percent and rear seat belt use was 81.7 percent.\10\ See Figure 1.
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\9\ Boyle, L.L. (2022, August). Occupant restraint use in 2021:
Results from the NOPUS Controlled Intersection Study (Report No. DOT
HS 813 344). National Highway Traffic Safety Administration. NOPUS
is the only nationwide probability-based observational survey of
seat belt use in the United States. The survey observes seat belt
use as it actually occurs at randomly-selected roadway sites, and
involves a large number of occupants (68,804 in 2021). NOPUS
observations are made during daylight hours and are not necessarily
representative of high-risk driving times when belt use may be
lower.
\10\ Boyle, L.L. (2023, November). Occupant restraint use in
2022: Results from the NOPUS Controlled Intersection Study (Report
No. DOT HS 813 523). National Highway Traffic Safety Administration.
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[[Page 396]]
[GRAPHIC] [TIFF OMITTED] TR03JA25.000
NHTSA has, over time, implemented a variety of strategies to
increase seat belt use. These have included sponsoring national media
campaigns, supporting the enactment of state seat belt use laws and
high-visibility enforcement, and facilitating or requiring vehicle-
based strategies.\11\ While such measures have helped make enormous
progress, the persistent gaps in seat belt use suggest that additional
approaches may be necessary.
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\11\ For example, NHTSA runs a Congressionally mandated High
Visibility Enforcement annual campaign focused on increasing seat
belt use. The Click It or Ticket nationwide campaign has been in
effect for about 20 years. It runs every year from mid-May through
the Memorial Day weekend, into the first week in June.
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Seat belt warning systems (also referred to as seat belt reminder
systems) are a vehicle-based strategy to increase belt use. Seat belt
warning systems encourage seat belt use by reminding unbuckled
occupants to fasten their belts and/or by informing the driver that a
passenger is unbelted, so that the driver can request the unbelted
occupant buckle up. The warnings provided by seat belt warning systems
typically consist of visual and audible signals. An optimized warning
system balances effectiveness and annoyance, so that the warning is
noticeable enough that the occupants will be motivated to fasten their
belts, but not so intrusive that an occupant may attempt to circumvent
or disable it or the public will not accept it. Research by NHTSA and
others shows that seat belt warning systems are effective at getting
unbuckled occupants to fasten their seat belts. (We take a closer look
at this research in Section VIII, Overview of Benefits and Costs, and
the FRIA.) \12\
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\12\ See also Section V of the NPRM (pgs. 61684-61685).
---------------------------------------------------------------------------
FMVSS No. 208 currently requires a short audio-visual seat belt
warning for the driver's seat belt on passenger cars; \13\ trucks and
MPVs with a GVWR of 4,536 kg (10,000 lb) or less (except for some
compliance options which do not require the warning); \14\ and buses
with a GVWR of 3,855 kg (8,500 lb) or less and an unloaded weight less
than or equal to 2,495 kg (5,500 lb).\15\ The standard does not require
seat belt warnings for any seating position other than the driver's
seat.\16\
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\13\ S4.1.5.1(a)(3); S7.3.
\14\ S4.2.6; S7.3.
\15\ S4.2.6 (with the exception of some compliance options).
\16\ See, e.g., Interpretation Letter from NHTSA to R. Lucki,
July 24, 1985 (``Thus, the intent was to require a warning system
for only the driver's position.''). All NHTSA interpretation letters
cited in this preamble are available at https://www.nhtsa.gov/nhtsa-interpretation-file-search.
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Manufacturers have two compliance options for the driver's
warning.\17\ The first option requires that if the key is in the ``on''
or ``start'' position and the seat belt is not in use, the vehicle must
provide a visual warning for at least 60 seconds, and an audible
warning that lasts 4 to 8 seconds. Under the second option, when the
key is turned to the ``on'' or ``start'' position, the vehicle must
provide a visual warning for 4 to 8 seconds (regardless of whether the
driver seat belt is fastened) and an audible warning lasting 4 to 8
seconds if the driver seat belt is not in use.\18\ The current seat
belt warning requirements (i.e., for the driver's seat only) have been
in the standard since 1974.\19\
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\17\ 49 CFR 571.208, S7.3.
\18\ The warning requirements for automatic belts in S4.5.3
mirror, with some differences, the first compliance option.
Automatic belts are rarely, if ever, installed in current production
vehicles, and NHTSA's regulations limit the seating positions for
which automatic belts may be used to rear seats.
\19\ 39 FR 42692 (Dec. 6, 1974).
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Although not required by NHTSA's regulations, most currently
produced vehicles have a seat belt warning for the front outboard
passenger seat. Based on data on total projected vehicle sales in the
United States for MY 2022 from the agency's New Car Assessment Program
(NCAP) Purchasing with Safety in Mind: What to Look For When Buying a
Vehicle program, almost all (about 97 percent) MY 2022 vehicles offered
for sale in the United States were equipped with a seat belt warning
for the front outboard passenger seat.\20\ Further, almost all vehicles
already provide an audio-visual seat belt warning for both front
outboard seats that is longer than the minimum warning for the driver's
seat belt currently required in FMVSS No. 208. However, the persistence
of the front seat belt warning, while often greater than the minimal
durations required by FMVSS No. 208, is not consistent across new
vehicles. Specifically, a little over half of MY 2022 vehicles provide
a visual warning that lasts until the belts at any occupied front
outboard seat are fastened, and almost all (about 93 percent) have an
audible warning lasting at least a minute and a half; however, less
than half have an audible warning lasting at least two minutes.\21\
This means that while many new vehicles have significantly enhanced
reminders, many do not. This disparity, along with the plateauing front
seat belt use numbers, suggests that the current regulatory minima are
[[Page 397]]
too short, and that in the absence of a requirement, persistent audible
reminders that could improve front seat belt use are not widely
available in the market.22 23 24
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\20\ Through the NCAP program, NHTSA sends annual requests for
safety information about new vehicles to vehicle manufacturers. This
includes specific questions on seat belt reminder systems. The focus
of this request for information is for vehicle models that will be
sold in the upcoming model year that have a GVWR of 4,536 kg (10,000
lb) or less, and this data generally covers all such vehicles
offered for sale in the U.S. for MY 2022. Throughout this document
we will refer to this data as our ``NCAP data'' or ``Purchasing with
Safety in Mind: What to Look For When Buying a Vehicle'' data or
information.
\21\ See NPRM, pgs. 61709-61711, and appendix A.
\22\ Mark Freedman et al. The Effectiveness of Enhanced Seat
Belt Reminder Systems Draft Report: Observational Field Data
Collection Methodology and Findings. 2007. DOT HS-810-844.
Washington, DC: National Highway Traffic Safety Administration.
\23\ N. Lerner et al. 2007. Acceptability and Potential
Effectiveness of Enhanced Seat Belt Reminder System Features. DOT HS
810 848. Washington, DC: National Highway Traffic Safety
Administration [hereinafter DOT 2007.
\24\ Transportation Research Board Study at 8, 25; Mark Freedman
et al., Effectiveness and Acceptance of Enhanced Seat Belt Reminder
Systems: Characteristics of Optimal Reminder Systems Final Report.
DOT HS 811 097.
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While almost all MY 2022 vehicles have a seat belt warning for the
front outboard passenger seat, under half come equipped with a rear
seat belt warning system. Rear seat belt warnings were first introduced
in the United States by Volvo around 2009. About 47 percent of MY 2022
vehicles, from 15 vehicle manufacturers, are equipped with a rear seat
belt warning system. Thus, while rear seat belt warnings have become
more widely deployed in recent years, the majority of the current fleet
still is not equipped with them.
In short, front seat belt use rates appear to have plateaued, and
rear seat belt use rates have persistently been below those for the
front seats. Moreover, unbuckled occupants continue to be
overrepresented in fatal crashes (51 percent), given the lower exposure
of unbelted occupants relative to belted occupants (because front seat
belt use was about 90 percent and rear seat belt use was 80 percent for
the period in question). In spite of the effectiveness of seat belts
and seat belt warnings, most new vehicles continue to lack a rear seat
belt warning, and, while many vehicles provide significantly enhanced
reminders for the front seats, many do not. This suggests a need for a
beneficial safety technology that is not being met in the vehicle
market. This final rule is intended to meet that need.
Rulemaking Petition, MAP-21 Mandate, and Prior Rulemaking Notices for
This Action
On November 21, 2007, Public Citizen and Advocates for Highway and
Auto Safety (Advocates, and, collectively, petitioners) petitioned
NHTSA to amend FMVSS No. 208 to require a seat belt warning system for
rear seats on passenger cars and MPVs with a GVWR of 4,536 kg (10,000
lb) or less.\25\ On June 29, 2010, the agency published a Request for
Comments document (RFC) on the petition.\26\ The RFC discussed the
agency's research and findings regarding rear seat belt warnings and
solicited comments. NHTSA subsequently granted the petition.
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\25\ Docket No. NHTSA-2010-0061-0002.
\26\ 75 FR 37343 (June 29, 2010) (Docket No. NHTSA-2010-0061).
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In 2012, Congress passed the Moving Ahead for Progress in the 21st
Century Act (MAP-21).\27\ That legislation contained two provisions
regarding seat belt warning systems. First, it repealed the 8-second
durational limit for the driver's seat belt audible warning.\28\
Second, it required the Secretary of Transportation to initiate a
rulemaking proceeding to amend FMVSS No. 208 to provide a safety belt
use warning system for designated seating positions in the rear
seat.\29\ It directed the Secretary to either issue a final rule, or,
if the Secretary determines that such an amendment does not meet the
requirements and considerations of 49 U.S.C. 30111,\30\ to submit a
report to Congress describing the reasons for not prescribing such a
standard.
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\27\ Public Law 112-141 (2012).
\28\ Id. at section 31202(a)(2) (repealing portion of 49 U.S.C.
30124).
\29\ Id. at section 31503. Authority has been delegated to
NHTSA. 49 CFR 1.95.
\30\ Section 30111 requires that a Motor Vehicle Safety Standard
meet the need for safety, be stated in objective terms, and be
practicable, among other requirements. See infra Section IV.
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In 2019, NHTSA published an Advance Notice of Proposed Rulemaking
(ANPRM) seeking comment on a variety of issues related to potential
rear seat belt warning requirements.\31\ NHTSA published the NPRM on
September 7, 2023.\32\
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\31\ 84 FR 51076 (Sept. 27, 2019) (Docket No. NHTSA-2019-0093).
\32\ 88 FR 61674.
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III. Other Seat Belt Reminder Requirements and Protocols
The Economic Commission for Europe (ECE) has instituted seat belt
warning requirements, and the European New Car Assessment Programme
(Euro NCAP) and the Insurance Institute for Highway Safety (IIHS) have
also included seat belt reminder systems in their respective ratings
protocols. Below we briefly summarize the seat belt reminder provisions
in each of these.
ECE Requirements
The ECE has issued an updated version of Regulation No. 16 \33\
(R16) that requires seat belt reminder systems in all front and rear
seats on new cars.\34\ The seat belt reminder system is required to
have both a start-of-trip warning and a change-of-status warning for
both the rear and front seats, though the exact requirements differ
somewhat for rear and front seats.
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\33\ ECE Regulation No. 16, Revision 10.
\34\ The regulation was introduced in two phases: September 1,
2019 for new vehicle types (i.e., all vehicle models with a new type
approval) and September 1, 2021 for all newly-produced and
registered vehicles.
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Rear seat requirements. R16 specifies a two-level warning. The
first-level warning is a visual warning and the second-level warning is
an audio-visual warning. The first-level warning applies at the start
of a trip and the second-level warning applies when a fastened belt
becomes unfastened during a trip. The first-level warning must activate
when the seat belt of any of the rear seats is not fastened and the
ignition switch or master control switch is activated. The first-level
warning must last at least 60 seconds or until the belt is fastened (or
the seat is no longer occupied, if equipped with occupant detection).
The second-level warning must activate when a belt becomes unfastened
and certain specified speed or distance thresholds are met and must
last for 30 seconds unless other specified criteria are met (e.g., the
belt is re-fastened).
Front seat requirements. The front seat belt warning requirements
are similar to the rear seat warnings, with some differences. First,
the first-level visual warning is only required to last 30 seconds, not
60 seconds. Second, the second-level audio-visual warning applies to
unfastened belts at the start of the trip as well as to changes in belt
status (i.e., a fastened belt that becomes unfastened).
The regulation also contains a variety of other requirements
relating to the seat belt warning systems (e.g., telltales, exemptions
for certain vehicles and seating positions). R16 also allows for short-
and long-term deactivation of both front and rear warnings.
The ECE requirements are discussed in more detail where relevant in
later sections of this preamble.
Euro NCAP
Euro NCAP introduced seat belt warnings in their assessment
protocol in 2002. The Euro NCAP protocol for Safety Assist systems
describes which features a seat belt reminder must have to qualify for
points in this area of assessment,\35\ which is then used to calculate
the overall vehicle rating.\36\
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\35\ Euro NCAP's overall safety rating is based on four areas of
assessment (Adult Occupant Protection, Child Occupant Protection,
Vulnerable Road Users, and Safety Assist).
\36\ European New Car Assessment Programme Assessment Protocol--
Safety Assist, Safe Driving, Version 10.3, December 2023.
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[[Page 398]]
Rear seat warnings. For rear seats, a visual signal must start once
the ignition switch is engaged. The visual signal must be at least 60
seconds long. Occupant detection is required for rear seats to be
eligible for a score; this is a new requirement that was instituted
after NHTSA published the NPRM. For systems without occupant
detection,\37\ the visual signal must clearly indicate to the driver
which seat belts are in use and not in use. For systems with occupant
detection on all rear seating positions, the visual signal does not
need to indicate the number of seat belts in use or not in use, but the
signal must remain active if a seat belt remains unfastened on any of
the occupied seats in the rear. No visual signal is required if all the
rear occupants are belted. For systems with rear seat occupant
detection, a 30-second audible signal needs to activate before the
vehicle reaches a speed of 25 km/h (15.5 mph) or before it travels 500
meters when any occupied seat has an unbuckled belt. When any seat belt
experiences a change of status at vehicle speeds above 25 km/h (15.5
mph), an audio-visual signal is required, with the visual signal
lasting 60 seconds and the audible warning lasting 30 seconds, unless
certain conditions are met.
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\37\ This language remains in the protocol as a precondition for
receiving a score for seats with occupant detection. In a vehicle
where not all the rear seats are equipped with occupant detection,
if seats without occupant detection do not meet these requirements
the seats with occupant detection would not receive a score.
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Front seat warnings. The Euro NCAP protocol requires that, to
receive points, at the start of a trip the system must provide a visual
seat belt warning that lasts until the belt is fastened \38\ and an
audible warning that activates when certain conditions are met and
generally must last at least about 90 seconds (the exact duration
depends on a variety of specified criteria, such as vehicle speed or
distance travelled). It also specifies an audio-visual change-of-status
warning that meets the requirements of the initial start-of-trip
warning.
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\38\ Section 3.4.2.1.
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Insurance Institute for Highway Safety (IIHS) Protocol
On December 2021, IIHS released its Seat Belt Reminder System Test
and Rating protocol.\39\ It sets out general requirements for the seat
belt reminder visual and audible signals for front outboard and rear
seating positions. It specifies that a visual signal must be displayed
in the instrument panel, overhead panel, or center console, indicating
an unfastened belt. The audible warning must begin if the seat belt is
unfastened at ignition and for change-of-status, and can cease when the
seat belt is unfastened, the vehicle is no longer in motion, or the
seat is no longer occupied. The protocol also has sound pressure level
and frequency requirements for the audible warning.
---------------------------------------------------------------------------
\39\ Insurance Institute for Highway Safety. (April 2024.) Seat
Belt Reminder System Test and Rating Protocol, Version III,
available at https://www.iihs.org/media/f15e5be9-ac62-4ea6-a88d-7511105bfff5/H3hGKQ/Ratings/Protocols/current/Seat%20Belt%20Reminder%20Test%20Protocol.pdf (last accessed May 16,
2024).
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For the rear seats, the IIHS protocol specifies that the visual
signal must activate within 10 seconds of the ignition being turned on,
that the signal must indicate whether the seat belt at each rear
seating position is fastened or unfastened, and that it must last at
least 60 seconds. It does not require a visual signal if the seat belts
at all occupied rear seats are fastened or if no rear occupants are
present. It allows the visual signal to be cancelled by the driver. For
a seat belt change-of-status in the rear seats when the vehicle is in
motion, it requires an audible and visual signal that lasts at least 30
seconds. It further specifies that the audible and visual signal can
stop when seat belts at the occupied rear seats are fastened, the
vehicle is no longer in motion, or the seats are no longer occupied.
For the front seats, under the IIHS ratings protocol, the primary
audible reminder signal for the front outboard seats must be at least
90 seconds in total duration to obtain an ``acceptable'' or ``good''
rating.
Unlike Euro NCAP, the IIHS rating system provides ratings (Poor,
Marginal, Acceptable, and Good) instead of points. For instance, if the
front-passenger seat has an audible signal that lasts less than 8
seconds it would be given a ``Poor'' rating. For a ``Good'' rating both
the driver and front-passenger belt reminder must have an audible
signal that lasts at least 90 seconds and meet the rest of the belt
reminder system requirements for an ``Acceptable'' rating, including
the requirements for a rear seat belt reminder system. Accordingly, a
vehicle cannot receive a ``Good'' rating without having a rear seat
belt reminder system, and a rear seat belt reminder system is not
required for all the other ratings. The protocol does not specify
occupancy criteria (that is, the smallest occupant (or the size and
weight corresponding to the smallest occupant)) that the system must be
able to detect.
IV. Statutory Authority
NHTSA is issuing this final rule pursuant to its authority under
the National Traffic and Motor Vehicle Safety Act (Safety Act). Under
49 U.S.C. chapter 301, Motor Vehicle Safety (49 U.S.C. 30101 et seq.),
the Secretary of Transportation is responsible for prescribing motor
vehicle safety standards. The responsibility for promulgation of FMVSS
is delegated to NHTSA.\40\
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\40\ See 49 CFR 1.95.
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Section 30111 of the Safety Act requires that an FMVSS be
practicable, meet the need for motor vehicle safety, and be stated in
objective terms.\41\ The Safety Act defines ``motor vehicle safety'' as
``the performance of a motor vehicle or motor vehicle equipment in a
way that protects the public against unreasonable risk of accidents
occurring because of the design, construction, or performance of a
motor vehicle, and against unreasonable risk of death or injury in an
accident, and includes nonoperational safety of a motor vehicle.'' \42\
``Motor vehicle safety standard'' means a minimum performance standard
for motor vehicles or motor vehicle equipment.\43\ When prescribing
safety standards, the Secretary must consider all relevant, available
motor vehicle safety information.\44\ The Secretary must also consider
whether a proposed standard is reasonable, practicable, and appropriate
for the types of motor vehicles or motor vehicle equipment for which it
is prescribed, and the extent to which the standard will further the
statutory purpose of reducing traffic accidents and associated
deaths.\45\
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\41\ 49 U.S.C. 30111(a).
\42\ 49 U.S.C. 30102(a)(9).
\43\ Section 30102(a)(10).
\44\ Section 30111(b)(1).
\45\ Section 30111(b)(3)-(4).
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The statutory criterion of practicability is multidimensional. Most
relevant to this rule, it means that in issuing this final rule, NHTSA
must balance benefits and costs, with safety as the preeminent
consideration.\46\ This requirement means that NHTSA ought not simply
choose the least costly regulatory option.\47\ It also means that
[[Page 399]]
the final rule must be reasonably feasible, both economically \48\ and
technologically.\49\ Importantly, however, the Safety Act does allow
NHTSA to issue technology-forcing safety standards.\50\ NHTSA must also
consider the public acceptability of safety standards \51\ and provide
adequate lead time.\52\
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\46\ See, e.g., Motor Vehicle Mfrs. Ass'n of U.S., Inc. v. State
Farm Mut. Auto. Ins. Co., 463 U.S. 29, 55 (1983) (``The agency is
correct to look at the costs as well as the benefits of Standard 208
. . . When the agency reexamines its findings as to the likely
increase in seatbelt usage, it must also reconsider its judgment of
the reasonableness of the monetary and other costs associated with
the Standard. In reaching its judgment, NHTSA should bear in mind
that Congress intended safety to be the preeminent factor under the
Motor Vehicle Safety Act.'').
\47\ See, e.g., Public Citizen, Inc. v. Mineta, 340 F.3d 39, 58
(2nd Cir. 2003) (``The notion that `cheapest is best' is contrary to
State Farm. There the Court instructed NHTSA `to look at the costs
as well as the benefits' of motor vehicle safety standards, and to
``bear in mind that Congress intended safety to be the pre-eminent
factor under the [Safety Act.] Thus, when NHTSA issues standards
under the Safety Act, State Farm requires that the agency weigh
safety benefits against economic costs; moreover, State Farm
instructs the agency to place a thumb on the safety side of the
scale.'') (quoting Motor Vehicle Mfrs. Ass'n of U.S., Inc., 463 U.S.
at 54) (citations omitted).
\48\ See, e.g., Public Citizen, Inc. v. Mineta, 340 F.3d at 58
(2nd Cir. 2003) (``The committee recognizes . . . that the Secretary
will necessarily consider reasonableness of cost, feasibility and
adequate lead time.'') (quoting H. Rep. No. 1776, at 16 (1966)).
\49\ See, e.g., Paccar, Inc. v. Nat'l Highway Traffic Safety
Admin., 573 F.2d 632, 635 n.5 (9th Cir. 1978) (``Practicable is
defined to require consideration of all relevant factors, including
technological ability to achieve the goal of a particular
standard[.]'') (citations and quotations omitted) (quoting H.R. Rep.
No. 1776, 89th Cong., 2d Sess. 16 (1966)).
\50\ Chrysler Corp. v. Dep't of Transp., 472 F.2d 659, 673 (6th
Cir. 1972) (``[T]he Agency is empowered to issue safety standards
which require improvements in existing technology or which require
the development of new technology, and it is not limited to issuing
standards based solely on devices already fully developed.'').
\51\ Pac. Legal Found. v. Dep't of Transp., 593 F.2d 1338, 1345-
46 (D.C. Cir. 1979) (``We believe that the agency cannot fulfill its
statutory responsibility unless it considers popular reaction.
Without public cooperation there can be no assurance that a safety
system can meet the need for motor vehicle safety.'') (quotations
and citations omitted).
\52\ 2 U.S. Code Cong. & Adm. News, 89th Cong., 2d Sess., 1966,
p. 2714, quoted in H & H Tire Co. v. U. S. Dep't of Transp., 471
F.2d 350, 353 (7th Cir. 1972). (``The committee recognizes . . .
that the Secretary will necessarily consider [in the issuance of
standards] reasonableness of cost, feasibility and adequate lead
time.'').
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In developing this final rule, the agency carefully considered
these statutory requirements and has concluded that it meets them. They
are discussed in more detail throughout the preamble and in the
regulatory analyses where relevant.
V. Summary of the NPRM
The NPRM had two main components. The first proposed requiring a
seat belt reminder for the rear seats. The second proposed changes and
enhancements to the seat belt warning requirements for the front
outboard seats, most notably an audio-visual warning that persists
until the seat belt at any occupied front outboard seat is fastened.
These proposed requirements would apply to passenger cars and trucks,
buses (except school buses), and MPVs with a GVWR of 4,536 kg (10,000
lb) or less.
Rear Seat Belt Reminder Requirements
The first component of the NPRM was a set of proposed requirements
for a seat belt warning for rear seats. The proposed requirements had
four main elements.
Visual warning on vehicle start-up to inform the driver of
the status of the rear seat belts. We proposed three different
compliance options from which manufacturers could choose for the rear
seat belt warning system. The first would require the system to
indicate how many or which rear seat belts are in use (the ``positive-
only'' option). The second would require the system to indicate, for
the occupied rear seats, how many or which rear seat belts are not in
use (the ``negative-only'' option). The third would require the system
to indicate, for the occupied rear seats, how many or which rear seat
belts are in use and how many or which rear seat belts are not in use
(the ``full-status'' option). Certain features would be required of all
the options. Each system would have to provide a continuous or flashing
visual warning, consisting of either icons or text, visible to the
driver. The visual warning would have to last for at least 60 seconds,
beginning when the vehicle's ignition switch is moved to the ``on'' or
``start'' position. All the systems would require that the vehicle be
equipped with technology to determine that the belt latch is
fastened.\53\ The negative-only and full-status compliance options
would additionally have required that the vehicle be equipped with an
occupant detection system (which facilitates these more informative
warnings).
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\53\ We note the preamble language imprecisely indicated the
necessity for a belt latch sensor. As discussed later in this
document, it was not our intention to require a specific technology.
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Audio-visual change-of-status warning. We proposed an
audio-visual warning whenever a fastened rear seat belt is unfastened
while the ignition switch is in the ``on'' or ``start'' position and
the vehicle's transmission selector is in a forward or reverse gear.
The warning would have to last for at least 30 seconds. We did not
propose any requirements for the volume or tone of the warning. The
intent of this warning was to alert the driver or other occupants to a
change in belt status during a trip. The warning would not be required
if a door is open, which would be the case if a rear passenger
unfastened their belt in order to exit the vehicle.
Requirements related to electrical connections. We
proposed to require that readily removable rear seats either
automatically re-establish the necessary electrical connections, or, if
a manual connection is required, have readily accessible connectors.
Further, vehicles with the negative-only compliance option would be
required to provide a visual warning to the driver if a proper
electrical connection has not been established for a readily removable
rear seat.
Owner's manual requirements. We proposed that the vehicle
owner's manual (which includes information provided by the vehicle
manufacturer to the consumer, whether in digital or printed form)
describe the warning system's features (including the location and
format of the visual warnings) and include instructions on how to make
any manual electrical connections for readily removable seats.
Front Outboard Seat Belt Warning Requirements
The NPRM included several enhancements to the seat belt warning
requirements for the front outboard seats. We proposed three main
changes.
Audio-visual warning on vehicle start-up for front
outboard passenger seat. We proposed to require a seat belt warning for
the front outboard passenger seat.
Increasing the duration of the audio-visual warning on
vehicle start-up. We proposed enhancing the front seat warning
requirements by requiring an audio-visual warning that remains active
until the seat belt at any occupied front outboard seat is fastened.
Vehicle manufacturers could adjust the characteristics of the auditory
warning signal (such as frequency and volume) to make the warning both
effective and acceptable to consumers. The proposal included specific
duty cycle characteristics.
Audio-visual change-of-status warning. We also proposed to
require an audio-visual change-of-status warning whenever a front
outboard seat belt is unbuckled during a trip (unless a front door is
open, to account for an occupant unfastening the belt to exit the
vehicle). The warning would be required to remain active until the seat
belt is refastened.
Proposed Compliance Date
We proposed a compliance date for the amendments to FMVSS No. 208,
``Occupant crash protection,'' as follows. Manufacturers would be
required to comply with the amendments as of the first September 1 that
is one year after the publication of the final rule for the front seat
belt warning system requirements and the first September 1 that is two
years after the publication of the final rule for the rear seat belt
warning system requirements, with optional early
[[Page 400]]
compliance. Multi-stage manufacturers and alterers would have an
additional year to comply.
Regulatory Alternatives
NHTSA considered alternatives to the proposed requirements. The
main alternatives NHTSA considered were the seat belt warning
requirements in ECE R16 and Euro NCAP. The proposed requirements were
identical or similar to ECE R16 and Euro NCAP in many respects but
differed from them in several ways. For instance, while the ECE rear
seat belt warning regulations allow a warning for an unfastened seat
belt at an unoccupied seat, the proposal would not allow this, because
we tentatively believed that the resulting ``false'' warning would
potentially annoy drivers and lead to behaviors that would decrease
system effectiveness. Another way the proposal differed from ECE R16 is
the duration of the front seat belt warning on vehicle start-up: R16
generally requires only a 30-60 second audio-visual warning; NHTSA
proposed a warning that lasts until the seat belt is buckled.
VI. Final Rule and Response to Comments
A. Rear Seat Belt Warning Requirements
1. Applicability
The proposal applied to all rear designated seating positions in
passenger cars and all rear designated seating positions certified to a
compliance option requiring a seat belt in trucks, buses, and MPVs with
a GVWR of 4,536 kg (10,000 lb) or less, except for school buses and law
enforcement vehicles. NHTSA's regulations define a bus as a vehicle
designed for carrying more than ten persons.\54\ The proposal included
small buses, which refers to buses with a GVWR not more than 10,000 lb;
this therefore includes high-capacity vans. However, the proposal did
not include medium-sized buses (with a GVWR 10,000 lb-26,000 lb) or
large buses (with a GVWR greater than 26,000 lb). We proposed to apply
the proposed requirements to the specified categories of vehicles
because these vehicles are required to have seat belts at all rear
designated seating positions and (except for some buses) a seat belt
warning for the driver's seat. We noted that some types of trucks and
MPVs (motor homes, walk-in van-type trucks, vehicles designed to be
sold exclusively to the U.S. Postal Service, or vehicles with a GVWR
between 8,500-10,000 lb carrying a chassis-mount camper) \55\ and over-
the-road buses that are also prison buses \56\ are not required to have
rear seat belts. In the NPRM we explained that we did not propose to
exempt special-purpose vehicle types such as ambulances because NHTSA
believed that they are typically customized after first sale.
---------------------------------------------------------------------------
\54\ 49 CFR 571.3 (``Bus means a motor vehicle with motive
power, except a trailer, designed for carrying more than 10
persons.'') (italics in original).
\55\ S4.2.7.1.
\56\ S4.4.3.3; S4.4.5.1.
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The proposed applicability was largely consistent with ECE R16,
with a few differences. The rear seat belt reminder requirements in R16
do not include vehicles that carry more than nine persons (including
the driver).\57\ There is also no weight specification for the
passenger vehicles to which R16 applies. R16 also exempts ``ambulances,
hearses, and motor-caravans as well as for all seats for vehicles used
for transport of disabled persons, vehicles intended for use by the
armed services, civil defense, fire services and forces responsible for
maintaining public order.'' \58\
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\57\ Section 8.4.1.2 (rear seat belt warning requirements apply
to M1 and N1 category vehicles); Consolidated
Resolution on the Construction of Vehicles (R.E.3) Revision 6,
Section 2.2.1 (category M1 vehicles) (``Vehicles used for
the carriage of passengers and comprising not more than eight seats
in addition to the driver's seat.'') and Section 2.3.1 (category
N1 vehicles) (``Vehicles used for the carriage of goods
and having a maximum mass not exceeding 3.5 tonnes [7,716 lb].'').
\58\ Section 8.4.1.3.
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Comments
NHTSA received comments that supported the proposal; comments that
recommended expanding the applicability; and comments that recommended
excluding additional vehicle types.
Some commenters specifically supported various aspects of the
proposal. Freedman Seating Company (FSC) and Mr. Koo supported the
vehicles covered by the proposal and Ms. Tombrello supported including
van-like buses because she believed some have been prone to misloading
of passengers and baggage. Mr. Stange agreed that the final rule should
exclude medium and large buses, due to the distraction the system would
create for the driver; problems with maintenance and sensor
reliability; and the fact that bus passengers are not required to wear
seat belts in some states.
Some commenters argued for including additional higher-capacity
vehicles that the proposal excluded. The National Safety Council (NSC)
and Ms. Tombrello supported including school buses (regardless of
weight) and Mr. Koo supported including school buses with a GVWR 10,000
lb and under. FSC supported extending the requirements to over-the-road
buses with a GVWR between 10,000 and 26,000 lb (except school,
perimeter seating and transit buses). NSC commented that the final rule
should include limousines. Relatedly, InterMotive Vehicle Controls
(InterMotive) commented that it manufactures an aftermarket seat belt
reminder system for buses and vans with a GVWR both below and above
10,000 lb.
On the other hand, some comments argued for excluding additional
vehicles from the requirements. The Alliance for Automotive Innovation
(Auto Innovators) and Mercedes-Benz and Mercedes-Benz Research and
Development North America (Mercedes) recommended exempting vehicles
with more than six rear seats or more than two rear rows, pointing to
challenges with providing the driver with the status information on all
seating positions via the instrument panel (or other in-vehicle
display) due to the number of seats that may need to be displayed. Auto
Innovators further commented that for high-occupancy vehicles with
removeable seats, an electronic control unit and other hardware are
needed, which leads to practicability concerns, including increased
costs for customers. Mercedes reiterated these practicability concerns.
The Recreational Vehicle Industry Association (RVIA) similarly
commented that this final rule should harmonize with R16 and not apply
to motor homes. RVIA raised several different issues specific to motor
homes. First, it explained that motor homes are used in unique ways
because they are used both for transportation and for temporary,
recreational, and seasonal use. As an example, RVIA discussed a
scenario where occupants are seated in a rear seating position with the
motor home turned on, but where the vehicle remains stationary, leading
to a false warning. Second, it commented that motor homes' rear seats
are often used for storage, which could again lead to false warnings.
Third, RVIA commented that, because motor homes are often equipped with
non-conventional seats that convert into a bed, developing wiring and
sensors that would not be damaged in the conversion process would be
challenging if not impossible. Fourth, RVIA commented that the rear
portion of a motor home also has its own electrical system with very
little interface with the chassis electronics. This lack of interface
between electrical systems is unique in comparison to other types of
vehicles that typically have seats installed in standard
[[Page 401]]
configurations in the same factory as the vehicle is assembled,
completed, and shipped. RVIA stated that there is currently not a way
to provide electronic signals from the seating positions in the rear
portion of the motor home to the sophisticated electronics controls
that are proprietary to the chassis manufacturers.
Finally, Braun Northwest (BNW) commented that the final rule should
exempt ambulances, giving essentially two different reasons. First, BNW
commented that the reason NHTSA gave for not exempting ambulances--that
they are typically customized after first sale--was factually
inaccurate. BNW commented that while some special-purpose vehicles may
be customized after first sale, that is not the case with ambulances.
BNW explained that data from the Ambulance Manufacturer's Division of
the National Truck Equipment Association indicates that van ambulances
with a GVWR under 10,000 lb, which would be affected by this NPRM,
comprise more than 20 percent of the annual production of United States
ambulance manufacturers. Second, BNW pointed out that, while circuited
buckles needed for seat belt buckle status indication are commonly
available and simple to install on the two- and three-point seat belts
commonly used on most vehicles, they are inherently problematic on the
four, five, and six-point belts needed on ambulances. BNW explained
that recent work facilitated by NHTSA resulted in a new SAE
International (SAE) recommended practice, SAE J3026 Ambulance Patient
Compartment Seating Integrity and Occupant Restraint, developed
specifically for testing occupant restraint systems in ambulances. All
three national ambulance standards (KKK-A-1822F, Federal Specification:
Star-Of-Life Ambulance; NFPA 1917 Standard for Automotive Ambulances;
and CAAS Ground Vehicle Standard) now require compliance with SAE
J3026. BNW indicated that the critical ramification of SAE J3026 for
the NPRM was that side-facing ambulance bench seats must be fitted with
four-point, five-point, or six-point seat belts. BNW commented that
there are practicability concerns with enabling buckle status
indication for these seat belts, including the problem of getting wires
from an emergency locking seat belt retractor to a circuited buckle
located at the center front of the occupant's torso. Additionally, BNW
argued that seat belt reminders may prevent medical personnel from
administering medical care, as changes in occupant position required to
render patient care would cause alarm indications that add distraction
and confusion in an environment where such distractions can have dire
consequences.
Agency Response
NHTSA is adopting the proposal except that the final rule contains
an additional exemption for ambulances.
The major difference between the vehicles to which R16 and the
final rule apply is that the final rule applies to small buses, which
typically include buses with up to about four rear rows--mainly high-
capacity passenger vans (10 to 15-passengers), such as Chevrolet
Express, Ford Transit, GMC Savana, and Mercedes Sprinter passenger
vans. However, because the rule applies only to vehicles with a GVWR
less than 10,000 lb, it would generally not include vehicles with more
than four rows.
We believe that including small buses such as these high-capacity
vans addresses an important safety need. As we explained in the NPRM,
we believe it is particularly important to include vehicles with a GVWR
greater than 3,855 kg (8,500 lb), but less than or equal to 4,536 kg
(10,000 lb), because this range includes high-occupancy vehicles.
Including these vehicles is important because an increasing number of
high-occupancy vehicles are used as personal vehicles and are not
solely used for work-related purposes.\59\ In addition, multiple rear
seats or rows make it more difficult for the driver to ascertain rear
seat belt use, so a warning could prove especially useful in these
vehicles. We think this requirement would be especially beneficial for
15-passenger vans, for which there is both an increased risk of
rollover (related to the occupancy level of these vehicles) and lower
seat belt use rates compared to other passenger vehicles.\60\
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\59\ See, e.g., https://media.ford.com/content/fordmedia/fna/us/en/news/2016/07/29/nothing-mini-about-this-van--ford-transit-attracts-large-familie.html (last accessed May 16, 2024).
\60\ Belt use rates among occupants in 15-passenger vans
involved in fatal crashes are significantly lower compared to other
passenger vehicles. See Subramanian, R. (2008). Fatalities to
Occupants of 15-Passenger Vans, 1997-2006. (Report No. DOT-HS 810
947). National Highway Traffic Safety Administration.
---------------------------------------------------------------------------
Providing a reminder in vehicles with multiple rear rows is
technically feasible. As we noted above, because the final rule applies
to vehicles with a GVWR 10,000 lb or less, it generally would not
include vehicles with more than four rear rows of seats, which should
make it easier to implement a reminder. We are unaware of any currently
produced full-size passenger vans having a rear seat belt reminder
system. We did find aftermarket solutions from abroad for medium to
large buses,\61\ and InterMotive commented that a seat belt warning
system already exists for multipurpose passenger vehicles with a GVWR
both below and above 10,000 lb. They currently manufacture an after-
market solution, SeatLink, for the bus and van market, including seats
supplied by Freedman Seating Company (Freedman). However, we do not
have any information on the performance and reliability of these
systems.
---------------------------------------------------------------------------
\61\ See https://www.phoenixseating.com/our-products/all-buckled-up and https://www.fsrtek.com/applications/bus-seat-belt-alarm-system (last accessed May 16, 2024).
---------------------------------------------------------------------------
We do acknowledge that vehicles such as high-capacity vans may
encounter visual signal complexities. Accordingly, our intent was to
propose performance requirements that provide manufacturers with the
flexibility to design a warning system that is appropriate for each
vehicle type (for example, the final rule does not require a full
schematic of the rear seats). For example, a visual warning option for
vehicles with multiple rows could be the seat belt icon with an
adjacent number corresponding to how many rear seat belts are fastened.
In addition, as we explain in more detail below (see Section
VI.A.2.a.i), in response to the comments, we have expanded the
compliance options to allow additional types of visual warning systems.
This too should help address any concerns related to feasibility.
The final rule, however, also follows the proposal in excluding
school buses and medium and large buses. As we explained in the NPRM,
extending the requirements to school buses would place additional cost
burden on school systems and may result in reductions in service; would
place additional burdens on the driver; and raises liability issues and
the potential for buses being out of service due to malfunctioning
systems. Many of these concerns were raised by commenters to the ANPRM
and we believe these concerns are still valid. Moreover, as we also
pointed out in the NPRM, school buses use compartmentalization, which
provides protection even to unbelted occupants. Similarly, the final
rule also excludes medium and large buses because of issues such as
those noted by Mr. Stange, including cost, reliability, and driver
burden.
The final rule also follows the proposal by including motor homes.
As an initial matter, we note that some motor homes are not required to
have
[[Page 402]]
rear seat belts so the requirements will not necessarily apply to all
motor homes. In addition, the seat belt requirements do not apply to
seats in motor homes with a GVWR over 10,000 lb and classified as MPVs
which the manufacturer designates and conspicuously labels as not
intended for occupancy while the vehicle is in motion.\62\ Accordingly,
such vehicles are not subject to the requirements in this rule.
Although we recognize that R16 exempts motor homes (motor caravans), we
see no reason to exclude from this rule designated seating positions
(DSPs) in motor homes that are required to have seat belts. Those DSPs
are designed to have passengers while the vehicle is in motion. Such
occupants would benefit from a seat belt and therefore, from a seat
belt reminder. We note that if the motor home is turned on for other
purposes than driving, the start-up warning is a 30-second visual
warning that should not be unduly annoying.
---------------------------------------------------------------------------
\62\ 49 CFR 571.3 (definition of ``designated seating
position''); FMVSS No. 207 S4.4.
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Limousines, depending on their characteristics, may also be covered
by the rule. Limousines are not currently a vehicle class defined in
the FMVSS. Depending on its characteristics, a limousine might be
classified as a passenger car, MPV, or bus.\63\ Generally, a passenger
car is designed for carrying 10 or fewer persons, an MPV is a vehicle
carrying 10 or fewer persons which is constructed either on a truck
chassis or with certain special features, and a bus is designed to
carry more than 10 persons. The final rule encompasses all these
vehicle types, so a limousine would be covered by the requirements as
long as it weighed 10,000 lb or less. At the same time, the FMVSS
generally apply to new vehicles, including new vehicles that are
altered, or vehicles manufactured in more than one stage. Limousines
(such as ``stretch'' limousines) that are the result of modifications
made to a vehicle after first purchase other than for resale would not
be required to be certified to the seat belt reminder requirements for
seating positions that are added in the modification process.\64\
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\63\ 49 CFR 571.3.
\64\ The Infrastructure, Investment and Jobs Act, H.R. 3684,
Sections 23015, 23023 (117th Congress) (2021), contains two
provisions that direct NHTSA to conduct research and issue rules (if
such rules would meet the criteria in section 30111 of the Safety
Act) related to various aspects of limousine crashworthiness and
occupant protection. NHTSA's research in these areas is ongoing.
See, e.g., DOT Regulatory Agenda, Fall 2023, RIN 2127-AM48, ``Seat
Belts in Limousines,'' available at https://www.reginfo.gov/public/do/eAgendaViewRule?pubId=202310&RIN=2127-AM48 (last accessed
December 16, 2024). The law also directs that the rules issued
pursuant to it apply to modified vehicles. However, that law also
defines the term ``limousine'' to, among other things, refer to
vehicles weighing between 10,000 and 26,000 lb. This would therefore
not include any limousines that are covered by this final rule,
which is limited to vehicles up to 10,000 lb. GVWR.
---------------------------------------------------------------------------
The one way the final rule does depart from the proposal with
respect to the applicability is by including an exemption for
ambulances from the rear seat belt warning system requirements.\65\
Given the information provided by BNW, the original intent of the rule
not applying to ambulances, and the fact that excluding ambulances
harmonizes with ECE R16, the final rule exempts ambulances. Although
neither FMVSS No. 208 nor 49 CFR 571.3 defines ``ambulance,'' FMVSS No.
201, ``Occupant protection in interior impact,'' defines it to mean ``a
motor vehicle designed exclusively for the purpose of emergency medical
care, as evidenced by the presence of a passenger compartment to
accommodate emergency medical personnel, one or more patients on
litters or cots, and equipment and supplies for emergency care at a
location or during transport.'' \66\ We are including a cross-reference
to this definition in the regulatory text. However, we have not
included a broader carve-out for emergency vehicles. We did not receive
any comments indicating that such a carve-out was necessary. Moreover,
there are a number of ways that owners and purchasers of emergency
vehicles for official purposes could disable the warnings. These owners
and purchasers already sometimes alter vehicles significantly.\67\
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\65\ This does not exempt ambulances from the front seat belt
warning requirements.
\66\ FMVSS No. 201, S3 (definitions).
\67\ Although section 30122 of the Safety Act prohibits making
inoperative required safety devices, this prohibition does not apply
to vehicle owners. See infra n. 91 and accompanying text.
---------------------------------------------------------------------------
2. Requirements
The NPRM proposed a 60-second visual warning on vehicle start-up; a
30-second audio-visual warning if a buckled belt is unfastened during a
trip; and requirements or criteria related to readily removable seats,
the owner's manual instructions, the location of the telltale, and how
NHTSA would determine that a belt was or was not in use. We discuss
these requirements in turn below.
a. Visual Warning on Vehicle Start-Up
The NPRM proposed a 60-second visual warning on vehicle start-up
that would inform the driver of how many or which seat belts are and/or
are not in use. We proposed three different compliance options for the
type of information conveyed to the driver. Occupant detection would
not be required for one of the three compliance options. The warning
would be triggered when the ignition is placed in the ``on'' or
``start'' position. When testing a system certified to one of the
compliance options necessitating occupant detection, NHTSA would seat a
dummy or human occupant corresponding to a 6-year-old. We discuss these
proposed requirements below in more detail.
i. Type of Information Conveyed by the Visual Warning and Whether
Occupant Detection Should Be Required
The proposed requirements for the rear seat belt warning system
(RSBWS) included a visual warning that would activate on vehicle start-
up to inform the driver of the status of the rear seat belts. We
proposed three different compliance options. The first would require
the system to indicate how many or which rear seat belts are in use
(the ``positive-only'' option). The second would require the system to
indicate, for the occupied rear seats, how many or which rear seat
belts are not in use (the ``negative-only'' option). The third would
require the system to indicate, for the occupied rear seats, how many
or which rear seat belts are in use and how many or which rear seat
belts are not in use (the ``full-status'' option). The negative-only
and full-status compliance options would require that the rear seats be
equipped with a mechanism to determine when a belt latch is fastened
and an occupant detection system (which facilitates these more-
informative warnings), while the positive-only option would only
require that the rear seats be equipped with a mechanism to determine
when a belt latch is fastened.
In the NPRM we stated that we had tentatively decided not to
require occupant detection in the rear seats because occupant detection
continued to present technical challenges which could reduce the
effectiveness and/or acceptance of these systems. This tentative
decision was also based on factors such as the needed increase in seat
belt use for this regulatory alternative to have positive net benefits.
Because we did not propose to require occupant detection, we also did
not propose requiring enhanced warnings (such as an audible warning on
vehicle start-up).
The proposal harmonized with ECE R16 and Euro NCAP in a variety of
ways, but also deviated from them in some respects.
[[Page 403]]
ECE R16 requires a visual warning at the start of a trip. That
warning ``indicate[s] at least all rear seating positions to allow the
driver to identify, while facing forward as seated on the driver seat,
any seating position in which the safety-belt is unfastened.'' \68\
Occupant detection is not required, but in vehicles that do have
occupant detection the warning does not need to indicate unfastened
belts for unoccupied seating positions.\69\
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\68\ Section 8.4.4.2.
\69\ Section 8.4.4.2.
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The Euro NCAP rating protocol also requires a visual warning at the
start of a trip. The requirements are similar to ECE R16. However, Euro
NCAP's rating protocol was recently revised to require occupant
detection in the rear seat to receive points for this feature. For
systems without occupant detection, the visual signal must clearly
indicate to the driver the seating positions showing the rear seat
belts in use and not in use. (These seats would not be eligible for
points, but in order for seats with occupant detection to receive
points the seats without occupant detection would have to meet these
requirements.) For systems with occupant detection, the visual signal
does not need to indicate the number of seat belts in use or not in
use, but the signal must remain as long as the seat belt remains
unfastened on any of the occupied seats in the rear.\70\ No signal is
required if all of the rear occupants are belted \71\ or no rear
occupants are detected.\72\
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\70\ Section 3.4.3.1.3.
\71\ Section 3.4.3.1.4.
\72\ Section 3.4.3.1.1.
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The IIHS rating protocol requires a visual signal indicating
``whether the seat belt at each rear seating position is fastened or
unfastened.'' \73\
---------------------------------------------------------------------------
\73\ Seat Belt Reminder System Test and Rating Protocol, Version
III at pg. 7.
---------------------------------------------------------------------------
The NPRM acknowledged that the proposed compliance options were not
consistent with all seat belt warning systems currently deployed in the
U.S. and Europe or with Euro NCAP's requirements. Specifically, we
noted that manufacturers appeared to be deploying systems that would be
categorized as either positive-only or negative-only except without
occupant detection, the latter of which would not be permitted under
the proposed compliance options. We also noted that the positive-only
compliance option did not appear to be consistent with Euro NCAP
because Euro NCAP requires that systems without occupant detection show
the rear seat belts in use and not in use, and the positive-only
compliance option would not permit a visual signal for an unfastened
seat belt.
Accordingly, while we tentatively concluded that the proposed
compliance options would help mitigate false warnings and the possibly
attendant consumer acceptance issues, we explained that we were
considering altering the proposed compliance options to accommodate
systems that are currently being deployed, or that manufacturers may
wish to deploy in the future.
Comments
Auto Innovators, General Motors (GM), American Honda Motor Co.
(Honda), and Hyundai America Technical Center, Inc. (HATCI) generally
supported including multiple compliance options in the final rule.
Freedman, Automotive Safety Council (ASC), Tesla, Advocates and Public
Citizen, and the National Automobile Dealers Association (NADA)
generally supported the proposed compliance options, although as noted
below some of these commenters preferred certain compliance options or
requested that additional compliance options be added.
Several commenters (Consumer Reports, Safe Kids Worldwide (SKW),
Paradise, NSC, Safe Ride News (SRN), Cross, and Ms. Tombrello) argued
that NHTSA should require occupant detection in the rear seats. Other
commenters (Freedman, IEE,\74\ ASC), while not explicitly recommending
that occupant detection be required, either preferred options requiring
occupant detection or focused on the benefits and feasibility of rear-
seat occupant detection. These commenters made a variety of arguments.
---------------------------------------------------------------------------
\74\ A supplier of automotive sensing systems.
---------------------------------------------------------------------------
Some commenters argued that the necessary technology for occupant
detection is feasible. Consumer Reports commented that occupant
detection does not pose unreasonable technical challenges, and is not
prohibitively expensive (see Section VIII, Overview of Costs and
Benefits). Consumer Reports and Mr. Paradise commented that rear-seat
occupant detection technology is already widely available; Mr. Paradise
also noted that 7 percent of vehicles already have the technological
capability of occupant detection in rear seats. NSC commented that
challenges with false positives (e.g., transportation of cargo and
pets) can be addressed through a relatively small investment, such as
with low-cost 2-D or digital cameras, and that costs would further
decrease over time if it were required. Consumer Reports noted that
occupant detection is already widely deployed in the front outboard
passenger seats. Relatedly, although not recommending that occupant
detection be required, IEE commented that today's occupant detection
sensors, predominantly designed for a detection of 5th percentile adult
female, can reliably differentiate occupants from cargo.
Several commenters focused on the benefits of requiring occupant
detection. Consumer Reports, Mr. Paradise, SKW, SRN, ASC, Ms. Cross,
NSC, and Ms. Tombrello commented that warning systems using occupant
detection would be more effective than those without it. Consumer
Reports, Paradise, Ms. Cross, and NSC noted that occupant detection
would enable enhanced warnings, which are more effective.
Accordingly, some of these commenters recommended requiring the
proposed full-status and/or negative-only options that required
occupant detection. Consumer Reports argued that NHTSA should require
the full-status compliance option because the ``positive-only'' and
``negative-only'' compliance options are insufficient to incentivize
rear seat belt use. Consumer Reports commented that the positive-only
option would be the least technically complex, but it would also be the
least effective type of warning system (because it creates unnecessary
mental work for the driver and allows room for human error). Consumer
Reports further explained that the positive-only system would be a
departure from Euro NCAP, which requires that systems without occupant
detection show both the rear seat belts in use and those not in use.
Consumer Reports also commented that given that both the negative-only
and the full-status options require a belt latch sensor and an occupant
detection system, the negative-only option should be eliminated because
the full-status option is more informative and effective. SRN, ASC,
NSC, and Ms. Cross similarly commented that NHTSA should require
negative-only or full-status systems, which would be more effective in
alerting caregivers to an unbuckled rear passenger than ``positive-
only'' systems. Ms. Cross commented that negative-only and full-status
systems can inform the driver whether any rear seat occupants are
unbuckled without having to make a comparison between number of seats
to the number of occupants and an audible component can be added. ASC
also noted that permitting only negative-only and full-status systems
would harmonize with the requirements in Europe.
[[Page 404]]
Consumer Reports, Cross, and SKW also recommended requiring
occupant detection because that feature could eventually be used for
other safety functions such as rear occupant alerts for vehicular
heatstroke prevention and air bag suppression. SKW and Ms. Cross
pointed to the potential to detect children or other vulnerable
occupants in child safety seats, booster seats, or seat belts.
On the other hand, vehicle manufacturers commented that the final
rule should not require occupant detection. Toyota Motor North America,
Inc. and Toyota Motor Corporation (Toyota) and Auto Innovators
commented that an occupant detection system can introduce false
positives. Several manufacturers requested removing the requirement for
occupant detection from one or both of the proposed compliance options
that required it (full-status and negative-only).
Toyota argued that NHTSA should allow negative-only systems without
occupant detection because an occupant detection system does not
provide any additional safety benefit for the negative-only system.
Toyota explained that it is reasonable to anticipate that a driver
knows whether a rear occupant is in the vehicle, and, as with a
positive-only system, can combine that knowledge with the information
from the visual indicator. Toyota also commented that a telltale
indicating a seat belt is not fastened at an unoccupied seat is not a
false positive, but is instead useful information for the driver.
More generally, several manufacturers and trade groups (Auto
Innovators, Ford Motor Company (Ford), Nissan North America (Nissan),
NADA, Honda, Hyundai Motor Company (Hyundai)) commented that NHTSA
should permit manufacturers to convey information on positive belt
status information (i.e., when belt is in use) and/or negative belt
status information (i.e., when the belt is not in use) without occupant
detection--that is, NHTSA should expand the proposed compliance options
to permit negative-only systems without occupant detection and/or full-
status systems without occupant detection.\75\ NADA argued that these
options would provide better contextual information for drivers than
the proposed full[hyphen]status option because they would provide seat
belt status information for all seating positions regardless of
occupancy. Nissan, Ford, and Auto Innovators argued that presenting
information on the seat belt status regardless of whether the seat is
occupied or not should not be deemed as misleading but rather as
furnishing the driver with pertinent contextual information concerning
seat belt usage across all positions. Nissan and Ford argued that this
information would empower the driver to distinguish easily between
buckled and unbuckled seat belts, particularly when compared to the
locations where known passengers are situated in the rear row. Auto
Innovators, Nissan, NADA and Ford commented that this approach would be
consistent with European regulations. Nissan, NADA, and Ford indicated
that this approach would align with ECE R16, and Ford and Auto
Innovators commented that the approach aligns with the IIHS approach.
Honda commented that systems without occupant detection that provide
visual information on both fastened and unfastened seat belts have been
in use in Europe for many years and are well understood by those that
use it regularly. Auto Innovators and NADA commented that not expanding
the compliance options in this way would require development and
deployment of new systems and increase cost and lead time for some
original equipment manufacturers (OEMs), which ultimately harms
consumers and hinders achievement of NHTSA's safety objective. Auto
Innovators further commented that it was unaware aware of any data that
would support NHTSA's claim that a visual indication of an unfastened
seat belt at an unoccupied seat would annoy drivers and argued that if
driver annoyance is a concern, NHTSA should consider allowing a
dismissible initial warning, as is the case with both IIHS and R16.
---------------------------------------------------------------------------
\75\ Some of the comments were ambiguous with respect to whether
they were referring to full-status systems, negative-only systems,
or both.
---------------------------------------------------------------------------
In addition, Ford, Toyota, and Honda raised concerns with the
proposed positive-only compliance option. Ford and Toyota commented
that it conflicts with R16 and the IIHS protocol. Honda commented that
if all rear occupants are unbuckled and there is no indication of their
status, the driver may remain unaware of the system's ability to
support the determination of the statuses of the belts for the rear
occupants.
Agency Response
In response to the comments, the final rule follows the proposal in
not requiring occupant detection, but modifies the proposal by revising
the requirements to allow full-status and negative-only reminder
systems without occupant detection.
The final rule follows the proposal in not requiring that rear seat
belt reminder systems be equipped with occupant detection. There are a
few reasons for this decision.
One reason is that we believe rear-seat occupant detection
continues to present technical challenges. This is especially the case
because we have concluded that rear-seat occupant detection systems
should be able to detect, at a minimum, occupant characteristics
matching a 6-year-old for determining whether a rear seat is occupied.
This standard differs from ECE R16 and Euro NCAP, both of which base
their requirements for occupant detection-equipped rear seat belt
reminder systems on the 5th percentile female. This difference is
discussed in more detail in Section VI.A.2.a.iv, Seat Occupancy
Criteria and Interaction with Child Restraint Systems. Rear-seat belt
reminder systems with occupant detection have only been recently
deployed in vehicles sold in the U.S. (starting in MY 2021 based on our
available data) and are currently offered on only a small proportion of
new vehicles.\76\ Based on the projected sales for MY 2022,
approximately 7 percent of vehicles were equipped with rear-seat
occupant detection. We have no data on how the occupant detection in
these vehicles is working.
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\76\ NHTSA does not have any specific information on the size of
occupant these systems are designed to detect. However, based on the
manufacturer comments requesting that NHTSA require occupant
detection systems to detect a 5th percentile female occupant, it is
likely that these systems are designed to detect occupants as small
as the 5th percentile female.
---------------------------------------------------------------------------
While occupant detection technology is readily available and
standard equipment in most front outboard passenger seats, the occupant
detection technology used for the front outboard passenger seat does
not necessarily translate directly to the rear seats. By comparison,
vehicles subject to advanced air bag requirements comply using either
suppression or low-risk deployment for different size child dummies,
including the 6-year-old child dummy, in the front outboard passenger
seat. Vehicles with a suppression system use some type of occupant
detection technology in addition to other inputs (e.g., seat belt use,
seat position, etc.) to determine whether or not to deploy the air bag.
Vehicles using low-risk deployment, however, do not necessarily need to
use occupant detection to meet the advanced air bag requirements for
that option. The vast majority of vehicles use the suppression option
in the front outboard passenger
[[Page 405]]
seat for at least one child dummy, and therefore use occupant
detection.77 78
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\77\ There is also an option to use a dynamic automatic
suppression system. To date, no manufacturer has attempted to
certify using this option.
\78\ With respect to the driver's seat, while it is subject to
certain advanced air bag requirements, those particular requirements
do not necessitate occupant detection.
---------------------------------------------------------------------------
Vehicle manufacturers that opt to use a rear seat belt warning
system with occupant detection will have to develop and implement
occupant detection solutions that work for the unique seat designs and
configurations found in rear seats (e.g., bench seats, folding seats,
different types of seat cushions, etc.) and validate the performance to
ensure that they meet the new requirements and mitigate the potential
for false positives. Among other challenges, rear seats create more
potential for false positives than the front seats. As we explained in
the NPRM and ANPRM, while occupant detection can reduce false warnings
for unoccupied seats, it can also result in false warnings, due to the
limitations of the sensors and different use scenarios in the rear
seats (e.g., transportation of cargo and pets). In addition, rear seats
may be less well-defined than front seats (most rear seat rows, unlike
the front seat rows, are comprised of three closely spaced seating
positions), which could impede accurate detection. This deficiency
could negatively affect consumer acceptance and/or effectiveness.
Another reason the final rule does not require occupant detection
is that it adds non-trivial costs to the seat belt warning system.
While we agree with Consumer Reports that rear-seat occupant detection
is not prohibitively expensive in the sense that this is true for some
vehicle lines, our cost-benefit analysis shows that occupant detection
would be cost-beneficial only if rear seat belt use increased
substantially more than we estimate it would for a warning system
without occupant detection. Our teardown analysis indicates that
occupant detection components cost $39.74 per vehicle, which, added to
the $19.59 per vehicle cost of the buckle sensor, results in a combined
warning system cost of $59.33 per vehicle (2020 $). We estimate that
the total new fleet cost of a rear seat belt warning system with
occupant detection would be about $802 million (2020 $). With respect
to benefits, there is uncertainty with respect to how much more
effective systems with occupant detection are compared to systems
without it. Because of this uncertainty, our regulatory analysis does
not attempt to estimate the net benefits or cost-effectiveness of rear
seat belt reminder systems that use an occupant detection system. The
regulatory analysis does, however, include a break-even analysis for a
rear seat belt reminder system that requires occupant detection. For
benefits and costs to break even (be equal) for this regulatory option,
seat belt use for rear seat occupants 11 years and older would need to
increase by approximately 5.2 percent when discounted at 3 percent and
6.4 percent when discounted at 7 percent. Furthermore, NHTSA considered
the increase in seat belt use for rear seat occupants that would be
required to match the net benefits under the final rule, which does not
require occupant detection. When discounted at three and seven percent,
seat belt use for rear seat occupants 11 years and older would need to
increase by 6.43 percent to 8.57 percent to match the net benefits
(taking into account the Low and High estimates) under the final rule.
This is about two to three times greater than that estimated for the
compliance option without occupant detection. (For more details, see
Section VIII.B.1 and the FRIA.) Accordingly, while we agree with the
commenters who supported a requirement for occupant detection because
there may be benefits to having occupant detection (such as
facilitating enhanced or more effective warnings) \79\ and would expect
some potential increase in seat belt use from that specific
functionality, an effectiveness increase of this order of magnitude
seems unlikely. Therefore, we do not expect this regulatory alternative
to be net beneficial and would not generate the same level of net
benefits as the final rule. Manufacturers may voluntarily equip
vehicles with occupant detection if they so choose. Our hope is that
over time, as the systems evolve and penetrate the fleet, the
technology will mature and per-unit costs will decrease.
---------------------------------------------------------------------------
\79\ With respect to SKW's comments about the benefits of
monitoring children in forward- or rear-facing CRSs, as we explained
in the NPRM, children restrained by child restraint systems are not
part of the target population for this rule.
---------------------------------------------------------------------------
With respect to the comment from Mr. Paradise concerning what he
believed was an inconsistency between NHTSA's statements that a single-
digit percentage of vehicles with rear-seat occupant detection being a
small percentage of the fleet, and weighing in favor of not requiring
it, and a single-digit percentage of vehicles with an indefinite
reminder being non-trivial and supporting our proposal to require an
indefinite reminder for the front seat belt start-of-trip warning, we
do not believe these statements are inconsistent. In the context of
occupant detection, we are referring to technological feasibility and
likely regulatory cost; in the front seat belt warning section, we are
referring solely to the optimum duration, as there is no question about
feasibility. That is, a single-digit percentage has a different meaning
in the two contexts.
Because we have decided not to require occupant detection, we
disagreed with commenters who recommended requiring one or both of the
proposed options that required occupant detection (full-status with
occupant detection or negative-only with occupant detection). We
continue to believe, as we explained in the NPRM, that while the full-
status system (with occupant detection) does provide the driver with
the most information, the other allowable types of systems, including
those without occupant detection, will provide the driver with
sufficient information to easily determine whether and where there are
any unbuckled occupants and request that they fasten their seat belts.
Accordingly, the final rule allows the proposed positive-only
option. These systems, while not providing information on the occupancy
status of each seat, do provide information on which seat belts are
buckled. The driver can combine this information with knowledge of the
other occupants in the vehicle and determine if there are any unbuckled
occupants and request them to fasten their belts. While this does
require mental work on the part of the driver, and may not be as
effective as a full-status system, we believe it is not so burdensome
as to render such systems ineffectual to such a degree that we see a
basis for prohibiting them. While such systems are not permitted under
ECE R16 or Euro NCAP, manufacturers could select another type of system
if they wished to harmonize with those protocols. (The positive-only
system without occupant detection does conform with the IIHS protocol.)
With respect to Honda's comment that the proposed positive-only option
could potentially leave the driver unaware that the vehicle was
equipped with a seat belt reminder system, we acknowledge that is a
possibility, but it would not be a long-term problem. This would be
limited to times when a driver is driving a vehicle new to them (unless
the driver always reads owner's manuals first) and would only be an
issue until a rear passenger buckles up. Once a rear passenger buckles
up the driver would become aware of the existence of the warning.
We have modified the proposal so that the final rule does not
dictate
[[Page 406]]
specific compliance options for the information conveyed by the visual
warning; the finalized requirements for the visual warning allow all of
the systems that would have been allowed under the proposed rule, as
well as additional systems that would not have been allowed under the
proposal, such as a negative-only system without occupant detection,
and a full-status system without occupant detection. Both the negative-
only system without occupant detection and the full-status system
without occupant detection are consistent with ECE R16 and the IIHS
protocol (they would not be eligible for points under Euro NCAP). One
factor underlying this choice is the lack of firm research data that
could lead NHTSA to meaningfully compare the effectiveness of the
different types of systems,\80\ coupled with the fact that rear seat
belt reminder systems conforming to the finalized requirements have
already been deployed on vehicles sold in the United States.\81\ These
factors make us reluctant to prohibit particular design choices and
inhibit manufacturer flexibility and ability to optimize system
characteristics. We believe that the finalized regulatory text (``A
visual warning indicating how many or which rear seat belts are in use
and/or not in use must activate when the ignition switch is placed in
the `on' or `start' position (or upon manual activation of the
propulsion system, but prior to the vehicle being placed in ``possible
active driving mode'' as defined by FMVSS No. 305))'' \82\ includes all
of the systems manufacturers are currently deploying, but is specific
enough to be objective and enforceable. For example, if there is one
rear occupant, and that occupant is belted, a positive-only system
without occupant detection that accurately indicates one buckled rear
belt, and a full-status system with occupant detection that accurately
indicates one rear occupant with a fastened belt, would both comply
with the finalized regulatory text.
---------------------------------------------------------------------------
\80\ See Mark Freedman et al., Effectiveness and Acceptance of
Enhanced Seat Belt Reminder Systems: Characteristics of Optimal
Reminder Systems Final Report. DOT HS 811 097 at pg. 49 (Feb. 2009)
(hereinafter ``DOT 2009 Seat Belt Study'').
\81\ An exception is a positive-only system with occupant
detection, which is not prohibited by the finalized requirements and
has yet to be deployed on vehicles sold in the United States.
However, we believe it would be unlikely that a manufacturer would
deploy such a system because the presence of occupant detection
allows for more informative reminders--for example, a full-status
reminder--than provided by a positive-only system. This is reflected
in the fact that while we are aware of production versions of
positive-only systems without occupant detection, negative-only and
full-status systems with and without occupant detection, we are not
aware of any vehicle equipped with both occupant detection and a
positive-only reminder system.
\82\ The language relating to EVs is discussed in Section
VI.C.1.
---------------------------------------------------------------------------
We agree with Toyota and Honda that the negative-only system
requires the same cognitive effort on the part of the driver as the
proposed positive-only option, and that it would still be effective and
beneficial, even without occupant detection. We no longer agree with
the view we expressed in the NPRM that such a signal is a false
positive that might either desensitize the driver to the warning signal
or lead them to circumvent or defeat the system. We now agree with
Toyota that this is instead more accurately considered relevant
information on seat belt status that the driver can use to determine
whether there are any unbuckled occupants and request them to fasten
their seat belts.
We reached a similar conclusion with respect to full-status systems
without occupant detection. As we discussed above for the negative-only
systems without occupant detection, we agree that while this system
does not provide as much information as would a system with occupant
detection, the information it does provide on the seat belt status at
every seating position (occupied or not) is useful information for the
driver. We also agree with the commenters who argued that allowing this
option would support the introduction of systems that are already in
widespread use, without adding in additional cost and complexity.
ii. Lack of an Audible Warning
The NPRM recognized that warnings with an audible component are
generally more effective than visual-only warnings. However, we also
recognized that requiring an audio-visual warning would necessitate
requiring occupant detection because, without occupant detection, an
audible warning would activate every time a rear seat is empty. These
``false positives'' would annoy the driver (as well as other occupants)
and would decrease the effectiveness of the warning. Thus, the NPRM did
not propose an audible warning on start-up. However, manufacturers
would be free to provide an audible warning on start-up if they so
choose. This approach is also consistent with ECE R16, Euro NCAP, and
IIHS.
Comments
Many of the commenters who supported requiring occupant detection
also supported requiring an audible warning (NSC, Consumer Reports,
SRN, Karleigh Cross, and an anonymous commenter). SRN, Consumer
Reports, and Ms. Cross commented that audible warnings are more
effective than visual-only warnings. Consumer Reports also commented
that requiring an audible component to the rear seat start-up warning
would also make start-up warnings more consistent throughout a vehicle,
regardless of the seating position.
Agency Response
The final rule does not require a rear seat audible start-of-trip
warning, for the reasons articulated in the proposal. Because the final
rule does not require occupant detection in the rear seats, it does not
require an audible warning. We acknowledge that audio-visual warnings
are more effective than visual warnings alone, and we believe that
consumers would accept them. However, we believe that a visual warning
alone will still be effective. While we cannot precisely estimate
effectiveness, we have used a three to five percent belt use rate
increase range (``lower'' and ``higher'' scenario) in our analysis
based on the available research. This analysis is explained in detail
in the FRIA. We agree that in general, consistency between the rear
reminder and front reminder requirements (which do require an audio-
visual start-of-trip warning) is desirable, but do not believe that not
requiring an audible component to the rear start-of-trip warning will
create an issue in practice. In this context, the relevant potential
concern with this inconsistency is that the driver--the recipient of
the warning--would be confused or annoyed by any differences in the two
warnings. Ultimately, we do not believe this inconsistency is a
significant problem. The front seat belt warnings have been in vehicles
for many years. Rear seat belt warnings will be new to most drivers, so
drivers will have to become accustomed to them. In addition, the rear
reminder will be a fairly prominent visual warning. If the driver is
unsure of how the warnings operate, this rule also requires that the
owner's manual include an accurate and easily understandable
description of system features and operation.
iii. Triggering Conditions for Start-of-Trip Warning (Not Including
Occupant Detection Criteria)
The NPRM proposed that the rear seat start-of-trip warning (which,
as discussed above, is only required to be a visual warning) activate
when the ignition switch is placed in the ``on'' or ``start'' position,
except for negative-only systems when there are no occupied rear seats
with a seat belt not
[[Page 407]]
in use (for which we proposed that a warning not be required to
activate). The activation criteria were modeled on the existing driver
seat belt warning requirements and are also similar to those in ECE
R16, Euro NCAP, and the IIHS protocol.
ECE R16 requires that the rear seat belt visual warning activate
when a belt is not fastened and the ignition or master control switch
activated.\83\ It also provides that for vehicles with rear seat
occupant detection, the visual signal does not need to indicate
unfastened belts at unoccupied seats.\84\
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\83\ Section 8.4.2.3.1.
\84\ Section 8.4.4.2.
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Euro NCAP similarly requires that the warning ```start' at the
commencement of each `journey' that the vehicle makes.'' \85\ More
specifically, the Euro NCAP protocol specifies that the visual signal
be activated ``when the ignition switch is engaged (engine running or
not) and a seatbelt is not fastened.'' \86\ However, Euro NCAP allows
for short breaks in the journey (up to 30 seconds) to account for
events such as engine stalling where the reminder is not required to
start again.\87\ Euro NCAP also provides that for systems with rear
seat occupant detection, the visual signal does not need to indicate
the number of rear seat belts in use or not in use.\88\
---------------------------------------------------------------------------
\85\ Section 3.4.1.
\86\ Section 3.4.2.1 (front); Sec. 3.4.3.1.1 (rear).
\87\ Section 3.4.1.
\88\ Section 3.4.3.1.3.
---------------------------------------------------------------------------
For the rear seats, the IIHS protocol permits a 10-second delay
between the ignition being turned on and the activation of the visual
signal. Similar to ECE R16 and Euro NCAP, no visual signal is required
for the rear seat belts if there are no unfastened belts at occupied
seats.
The major differences between the proposal and other approaches
were that, unlike ECE R16, we did not propose to refer to a ``master
control switch'' because we did not believe it is necessary to
introduce this new term into FMVSS No. 208; unlike Euro NCAP we
proposed not allowing for short breaks in the journey; and unlike IIHS
we did not propose allowing any delay after the ignition was turned on.
Comments
Commenters differed on whether the start-of-trip warning should be
permitted to be delayed. HATCI and Ford supported the proposed trigger
conditions (which did not permit a delay). On the other hand, Auto
Innovators, NADA, Freedman, and Nissan recommended allowing a delay.
Nissan, Auto Innovators, and NADA recommended aligning with the IIHS
protocol and permitting a 10-second delay, while Freedman favored a 30-
second delay. Auto Innovators also commented that while it generally
supports the agency harmonizing with ECE R16, the agency should
maintain flexibility for when these warnings are displayed on startup
and allow for a brief delay for when the alert is provided. Freedman
also commented that certain systems, such as an electronic system
separate from that of the OEM system, will require a powerup and boot
cycle which can take several seconds.
Auto Innovators also requested that the final rule allow the visual
warning to be suppressed if all rear row seating positions are belted
or determined to be empty based on occupant detection.
Lastly, RVIA explained that motor homes can be used in many ways
other than for transportation, such that the ignition may be turned on
with occupants seated in the rear accessing the vehicle's amenities,
but with no intention of placing the vehicle in motion. RVIA was
concerned that such use of the rear seats would trigger the rear seat
belt visual warning, even though the motor homeowner has no intention
of operating the vehicle. RVIA concluded that a visual warning system
on vehicle start-up would often go unnoticed in this scenario, creating
a requirement not suitable for the application of the start-up trigger
in a motor home.
Agency Response
The final rule adopts the proposal for the warning to activate on
start-up, with no provision for a delay. We continue to believe that
basing the trigger on the ignition switch is preferable to delaying the
warning until the vehicle is placed in gear because with a delay, there
could be instances where a driver would pull out onto the road before
the warning starts and before passengers have belted. The finalized
requirements increase the likelihood that the occupants fasten their
belts before the vehicle is in motion.\89\ With respect to mitigating
interaction with other vehicle warnings, NHTSA does not believe this
will be an issue at vehicle start-up because critical safety warnings
that activate at start-up would likely have dedicated space on the
display. Interactions between warnings is discussed in more detail in
Section VI.C.4. We believe consumers will accept this start-up warning.
The longstanding current front seat belt warning is based on similar
triggers and has not caused any issues. In addition, the rear start-of-
trip warning is visual-only, so any potential annoyance is minimized.
This factor distinguishes the rear-seat warning from the front seat
belt warning, which we are requiring to be both audio-visual and to
have two phases. We acknowledge there may be some scenarios during a
trip where a rear seat belt warning is not required for an unbuckled
occupant; for example, a passenger pickup scenario when the car is not
turned off. In such a scenario, we are not requiring a warning because
we are not requiring occupant detection, which would be necessary to
detect the new occupant (and potentially avoid a false warning).
Manufacturers of vehicles with rear-seat occupant detection may choose
to provide warnings for such situations.
---------------------------------------------------------------------------
\89\ See DOT 2009 Seat Belt Study at pg. 65.
---------------------------------------------------------------------------
In addition, we are modifying the proposed trigger condition
related to the vehicle ignition being in the ``on'' or ``start''
position for both the front and rear seat belt warning to better
account for EVs. This change is discussed in Section VI.C.1. This
modification generally harmonizes with ECE R16, Euro NCAP, and the IIHS
protocol, so that a vehicle that complies with the finalized trigger
requirements can still meet these requirements; some exceptions are
discussed immediately below.
In addition, we have also modified the proposal so that the final
rule does not require a visual warning in three circumstances: (1) for
an unoccupied seat if the system is able to determine whether a seat is
occupied; (2) for a seat belt that is in use in a system designed to
indicate to the driver how many or which rear seat belts are not in
use; and (3) for a seat belt that is not in use in a system designed to
indicate to the driver how many or which rear seat belts are in use.
This regulatory text is intended to clarify two things.
First, that, depending on the type of seat belt reminder system and
belt use/occupancy scenario, a visual signal may not be necessary for a
particular DSP, or may not be necessary for any DSP. So, for example,
no visual warning would be required for a negative-only system when
every rear seat is occupied by a belted occupant. Another example: if
no rear seats are occupied, no visual signal is required for negative-
only, positive-only, or full-status systems with occupant detection; a
visual warning would, however, be required in this case for a negative-
only system without occupant detection (assuming that no rear belts
were in use) and a full-status system without occupant detection.
[[Page 408]]
This requirement is consistent with ECE R16, Euro NCAP, and IIHS.
Second, this also clarifies, in response to the comments, that
systems utilizing symbols or numbers may utilize colors other than
green or red to indicate unoccupied seats or seating positions for
which the system is not providing information on belt use. Accordingly,
a negative-only system would be permitted to display a pictogram that
denotes a seating position with an in-use belt as grayed-out (to give
one example).\90\
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\90\ See also Section VI.C.3, Visual Warning Characteristics.
---------------------------------------------------------------------------
Freedman's comment regarding certain vehicles requiring more time
to boot up appears to be referring to accommodating aftermarket
systems. Because the final requirements apply to vehicles before first
purchase other than for resale, they do not directly apply to
aftermarket systems that are installed later on. However, Sec. 30122
of the Safety Act prohibits a vehicle modifier from taking a vehicle
out of compliance with an applicable FMVSS.\91\ (The vehicle owner is
not subject to the make inoperative provision). Therefore, a vehicle
modification performed after the compliance date of this final rule on
a vehicle with a rear seat belt warning system certified to the
requirements in this rule that modifies the vehicle such that the rear
seat belt visual warning does not activate when the ignition is in the
``on'' or ``start'' position (or upon manual activation of the
propulsion system, but prior to the vehicle being placed in ``possible
active driving mode'' as defined by FMVSS No. 305) \92\ would violate
Sec. 30122 and would therefore not be permitted.
---------------------------------------------------------------------------
\91\ 49 U.S.C. 30122(b) (``A manufacturer, distributor, dealer,
rental company, or motor vehicle repair business may not knowingly
make inoperative any part of a device or element of design installed
on or in a motor vehicle or motor vehicle equipment in compliance
with an applicable motor vehicle safety standard prescribed under
this chapter unless the manufacturer, distributor, dealer, rental
company, or repair business reasonably believes the vehicle or
equipment will not be used (except for testing or a similar purpose
during maintenance or repair) when the device or element is
inoperative.''); section 30122(a) (``(a) Definition. In this
section, ``motor vehicle repair business'' means a person holding
itself out to the public to repair for compensation a motor vehicle
or motor vehicle equipment.'').
\92\ See Section VI.C.1.
---------------------------------------------------------------------------
The final rule does not incorporate RVIA's request to accommodate
use scenarios specific to Recreational Vehicles (RVs). We agree that in
the scenarios identified by RVIA the warning would activate when the
vehicle was turned on with no intent to drive (thus obviating the need
for a seat belt). A speed or motion trigger could address this issue,
but we believe that such a trigger is undesirable because there is a
safety benefit to having occupants belted before the vehicle is in
motion or when it is travelling at lower speeds. Moreover, because the
rear seat belt start-of-trip warning is visual-only, there are not the
same consumer acceptance concerns that led us to include a speed
criterion like we have included for the second-phase front seat belt
audible warning. (See Section VI.B.3.) We could also potentially
address this concern by either exempting RVs or crafting trigger
criteria specific to RVs. We conclude the former is undesirable due to
the significant safety benefit of belts when the vehicle is in motion,
and that the latter would be overly complex. In addition, the rear seat
belt start-of-trip warning is a mild visual warning that should not
cause meaningful consumer annoyance (or condition them to ignore the
warning) in these use cases.
iv. Seat Occupancy Criteria and Interaction With Child Restraint
Systems
For rear seat belt warning systems that manufacturers voluntarily
choose to equip with occupant detection, NHTSA proposed the occupancy
criteria for the test dummy (or human, at the manufacturer's option)
that NHTSA would position in the seat to conduct compliance testing of
the system. NHTSA proposed that a rear designated seating position
would be considered ``occupied'' when an occupant who weighs at least
46.5 lb (21 kg), and is at least 45 in (114 cm) tall, is seated there.
These criteria are proxies for a 6-year-old child, which roughly
corresponds to a typical age at which a child would begin using a seat
belt (with a booster seat), transitioning from a forward-facing child
restraint system (CRS). These are the same criteria used in FMVSS No.
208 to specify the smallest child that may be used as an alternative to
the 6-year-old dummy in static suppression tests under FMVSS No. 208.
We proposed using either a human being, at the manufacturer's option,
or any anthropomorphic test device specified in 49 CFR part 572 that
meets these proposed weight and height criteria (Section VI.C.8., Test
Procedures).
The proposed criteria corresponded to a smaller occupant than ECE
R16 or Euro NCAP, each of which essentially specifies an occupant (or
load) no smaller than a 5th percentile adult female (e.g., the HIII-5F
specified in 49 CFR part 572). In the NPRM we explained that we
believed that harmonizing with ECE R16 and using a heavier dummy would
not capture the child segment of the population that could be
restrained with a seat belt. We also did not believe it was necessary
to use a larger-size occupant because a system capable of recognizing a
6-year-old should also be capable of recognizing larger occupants.
At the same time, we tentatively believed that the proposed
criteria were preferable to criteria reflecting a younger occupant
(lower weight). The smallest dummy that would meet the proposed weight
and height criteria is the 6-year-old dummy specified in part 572. The
next smallest dummy represents a 3-year-old child (i.e., the Hybrid III
3-year-old); we believed it would not be appropriate to specify the use
of the 3-year-old because a child represented by this dummy should be
seated in a forward- or rear-facing CRS, not restrained with a seat
belt.
NHTSA did not propose to require any sort of CRS detection
capabilities. As explained in the NPRM, there are essentially three
types of CRSs: rear-facing CRSs, forward-facing CRSs, and booster
seats. Rear-facing and forward-facing CRSs are child seats that are
installed using either Lower Anchors and Tethers for Children (LATCH)
or a seat belt to secure it in place. Booster seats raise and position
a child so the vehicle's lap-and-shoulder belt fits properly. We
tentatively believed that a forward- or rear-facing CRS installed with
the seat belt would not cause problematic false warnings; rather the
system would just register the CRS as a buckled passenger. Similarly,
we believed that a forward- or rear-facing CRS installed with LATCH
would not pose issues necessitating any specific requirements related
to the LATCH system, such as LATCH sensors.
We also did not believe a booster seat would present any special
challenges to a seat belt warning system. If an unbelted child is in a
booster seat, the system would register the belt as not fastened and,
if equipped with occupant detection, that the seat was occupied. The
system would not have to specifically detect the booster seat because
the performance criteria are weight-based. In addition, we would not
expect an occupant detection system to provide a false warning for an
unoccupied booster seat because the proposed seat occupancy criterion
(roughly equivalent to a 6-year-old) is heavier than an unoccupied
booster seat. We did not propose to specify the use of a booster seat
for testing because children may be prematurely transitioned to a seat
belt without the use of a booster, and we believe it is desirable to
test the lower end of the
[[Page 409]]
possible weight range that encompasses children that could conceivably
be restrained with a seat belt.
Comments
A number of commenters (Auto Innovators, Mercedes, GM, NADA, IEE,
Honda, HATCI, and Consumer Reports) disagreed with the proposal and
recommended harmonizing with ECE R16 and Euro NCAP and specifying
occupancy criteria based on a 5th-percentile adult female occupant.
These commenters made a variety of arguments.
Auto Innovators commented that harmonizing with the ECE
requirements would avoid introducing unnecessary complexity and reduce
the need for additional lead time to develop U.S.-specific designs. IEE
commented that the proposed detection criterion would entail
significant additional costs.
IEE also commented that a detection criterion based on the 5th
percentile female would address the key target population of unbelted
teenagers and adults. Relatedly, IEE noted that the NPRM analysis
investigated potential benefits for the age group 6 to 10 years old and
only found a very small belt usage increase (by only 0.27 percent to
0.41 percent) and concluded that members of this age group already have
high rates of seat belt use (98 percent according to the preliminary
regulatory impact analysis).
Consumer Reports, IEE, Auto Innovators, Honda, HATCI, NADA, RVIA,
and GM raised concerns regarding feasibility. Consumer Reports agreed
with NHTSA on the importance of testing the lower end of the possible
weight range that encompasses children that could conceivably be
restrained with a seat belt alone, but believed that it would be
premature to require the detection of dummies smaller than the 5th
percentile adult female because the ability to detect occupants smaller
than the 5th percentile adult female is limited. IEE commented that
while detecting a 5th percentile female is well-established in the
market and would not present any design or technical challenges, it was
not aware of any car on the market that would be able to meet the
proposed detection of the 6-year-old child scenarios, with or without a
booster cushion. IEE commented that the 5th percentile female is the
state-of-the art in contemporary sensing technology for seat belt
reminder-related occupant detection and that no realistic alternative
technologies are readily available at comparably low costs. IEE stated
that it believed that the 7 percent of U.S. MY 2022 vehicles with rear
seat occupant detection all meet the 5th percentile female detection
criterion, not the one 6-year-old proposed in the NPRM.
IEE also commented that the proposal assumed that a 6-year-old
child on the booster seat would be automatically covered and detected
as it has a higher total weight than the weight proposed for the
occupancy criteria. IEE stated that this assumption is wrong: rear
occupant detection systems are designed to detect a load that is
generating a pressure profile on the seat foam that matches the
pressure profile of a human buttocks. IEE commented that the pressure
profile generated by a booster seat is different and would not be
classified by the system as an occupant; contemporary occupant
detection sensors used for seat belt reminder systems are not designed
to detect booster seats, and child seats are considered as non-
detection objects. IEE indicated that this distinction is also required
to differentiate between humans and objects, to avoid objects that
would be likely to trigger false positives. Auto Innovators similarly
commented that the contact area between a booster seat and a seat
cushion can vary, causing some of the occupant's weight to be
distributed to the seat itself or to the LATCH system, rather than to
the weight sensor.
Auto Innovators also pointed out that child occupants are also more
likely to be out-of-position compared to an adult, further contributing
to uneven weight transfer. Auto Innovators argued that if the weight of
a child in a booster seat is not transferred to the weight sensor, the
proposed system could misclassify the seat as empty. If this
misclassification occurs, coupled with the lack of a visual warning for
an unfastened seat belt at an unoccupied seat, Auto Innovators argued
there would be no visual warning for cases where an age-appropriate
child is sitting in a booster seat and not wearing a belt. Relatedly,
IEE commented that more advanced detection technologies (such as
cameras or radar sensors) are not currently used in the context of a
seat belt reminder function, and that these technologies would still
have to prove their reliability and robustness for the occupant
detection needs of a seat belt reminder system. IEE explained that
while future developments may enable the support of seat belt reminder
functionalities with these technologies, it is too early to consider
such a potential innovation in a regulatory pass/fail scenario.
Honda, HATCI, Auto Innovators, NADA, IEE, RVIA, Honda, and GM
commented that specifying criteria matching a 6-year-old would
exacerbate the problem of false positives. HATCI and IEE commented that
behavioral alternatives to avoid false positives, such as moving cargo
to the floor of the vehicle or buckling the belt before loading heavy
cargo onto seats, may not always be feasible or reliable. Auto
Innovators and Honda argued that the proposed criteria would
potentially discourage manufacturers from implementing occupant
detection systems due to the potential for false warnings.
IEE similarly commented that if the agency were to adopt the 6-
year-old criterion proposed in the NPRM, manufacturers would be
disincentivized from implementing occupant detection in rear seats. IEE
explained that because the proposed detection threshold is not
technically feasible today within a regulatory pass/fail context, the
threshold proposed in the NPRM would fail advanced rear seat belt
reminder systems that have already entered the U.S. market and that
offer a seat belt warning functionality that exceeds the proposed legal
minimum. IEE stated that this requirement would force vehicle
manufacturers to withdraw these advanced seat belt reminder systems
from the market and downgrade the seat belt reminder systems features
to the legal minimum (the positive-only compliance option). IEE argued
that this result would be counterproductive from a safety perspective.
IEE and Consumer Reports commented that manufacturers could
voluntarily detect occupants smaller than the 5th percentile female.
IEE argued that making such detection voluntary would provide
flexibility for innovation. Consumer Reports recommended that NHTSA
incorporate detection of dummies smaller than the 5th percentile female
into NCAP ratings for rear seat belt reminders, which would award
manufacturers for going above and beyond the regulatory minimum and
drive innovation.
On the other hand, NSC and SRN suggested a 3-year-old child for the
occupancy criterion. NSC commented that data from the National Digital
Car Seat Check Form show that many children are not riding in the
appropriate CRS based on their height and weight, so specifying
criteria corresponding to a 3-year-old child would protect children.
SRN similarly noted that the weight of a 3-year-old dummy, though
average for a toddler, is also the weight of many older children in the
lower growth chart percentiles. SRN argued that since nearly all
school-age children ride in seat belts or boosters (including these
lighter-weight
[[Page 410]]
children, regardless of NHTSA best-practice recommendations), families
would benefit from warnings about the belt-use status of those
children. SRN explained that this is especially true for warnings that
a passenger has unbuckled during a ride, which younger, less mature
children may be prone to do. SRN explained that, as proposed, a system
with occupant detection would not recognize some of the youngest
booster/belt users, may provide inadequate warnings to families, and
may cause caregivers some frustration in interpreting status
indicators. SRN also commented that in comments to the ANPRM, SRN had
voiced the concern that LATCH-installed car seats could trigger false
alarms. SRN was less concerned that the proposed system will rise to
the level of nuisance and is more concerned that false warnings will
happen, such as when relatively heavy car seats are installed using
LATCH. SRN argued that owners will need clear guidance in owner's
manuals on how to interpret warnings when traveling with children, and
that these instructions should be included (or at least referenced) in
the child passenger section of the manual.
Consumer Reports, HATCI, and Freedman agreed with NHTSA that a CRS
detection requirement was not necessary. Consumer Reports stated that
consumers might be better served by incorporating CRS detection into a
component of NCAP for rear seat belt reminder systems to help drive
safety innovation. Freedman commented that the easiest and most
effective solution for LATCH-installed CRS is to continue recommending
the seat belt be fastened behind the CRS.
Auto Innovators and GM recommended that NHTSA ensure a technology-
neutral approach that includes consideration of compliance options that
permit the use of camera- or vision-based sensors, or other
technologies that may be adopted in lieu of weight-based sensors, as a
means for determining occupant presence at a given designated seating
position. Advocates and Public Citizen commented that the final rule
should not preclude or discourage the use of existing state-of-the-art
technology.
Agency Response
After considering the comments, NHTSA has decided to adopt the
proposal to use (at the option of the manufacturer) either a
anthropomorphic test device at least as large as a 49 CFR part 572,
subpart N 6-year-old child dummy or a person, at the manufacturer's
option, that is at least 21 kg in weight and 114 cm in height to define
an occupied rear designated seating position for the purposes of
testing the rear seat belt reminder system. These criteria represent a
50th percentile 6-year-old child, and only specify the low end of the
occupancy criteria used for compliance testing. Therefore, when we
refer to a 6-year-old as our occupancy criteria, this includes
occupants or dummies that are larger.
Before addressing the specific issues raised by the commenters, it
is important to recognize that this final rule does not require or
necessitate occupant detection. Moreover, we recognize that a
manufacturer currently deploying reminder systems with occupant
detection based on the 5th percentile female would likely need some
time and effort to develop and implement new sensor solutions in the
rear. Based on MY 2022 NCAP data, approximately 7 percent of vehicles
sold in the U.S. are equipped with rear seat belt reminders using
occupant detection. The commenters, however, did not provide specific
information on what additional development would be necessary to meet
the requirements when tested with a 6-year-old.
Further, as explained above (Section VI.A.2.a.i) we have revised
the proposed requirements to provide greater flexibility for systems
without occupant detection. The proposal only included one compliance
option (the positive-only compliance option) without occupant
detection. In response to the comments, the final rule would allow for
additional warning systems without occupant detection (e.g., negative-
only and full-status). Given this flexibility, manufacturers can simply
use reminder systems without occupant detection if they believe they
cannot deploy a reminder system using occupant detection that would
comply with the requirements when tested with a 6-year-old.
Given the above, NHTSA has concluded that it would fulfill the MAP-
21 mandate, meet the need for safety, and be practicable and
appropriate to require that an occupant detection system be capable of
detecting at least a 6-year-old. There are several reasons for this
decision.
First, section 31503 of MAP-21 directs NHTSA to initiate (and
finalize, if the Sec. 30111 criteria are met) a rulemaking proceeding
``to provide a safety belt use warning system for designated seating
positions in the rear seat.'' Section 31503 itself does not refer to
particular classes of occupants or identify a target population.
``Subtitle E--Child Safety Standards'', in which Sec. 31503 is
located, however, contains four mandates related to child passenger
safety: improving the protection seated in CRSs during side impact
crashes; improving the ease of use for LATCH systems; providing seat
belt reminders for rear seats; and researching the risk of hyper- or
hypothermia to children or other unattended passengers in rear seating
positions.93 94
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\93\ See, e.g., Norman J. Singer & Shambie Singer, 2b Sutherland
Statutory Construction section 46:5 (7th ed.) (``[E]ach part or
section of a statute should be construed in connection with every
other part or section to produce a harmonious whole. Thus, it is not
proper to confine interpretation to the one section to be
construed.''); section 47:3 (explaining that while legislative
titles cannot control a statute's plain words they ``may help
resolve uncertainty'' and ``illuminat[e] statutory meaning''). See
also id. section 47:6 (``Courts give effect to all the language of a
purview as a harmonious whole, in light of the statute's purpose,
and regardless of sectional formatting, unless to do so is plainly
contrary to legislative intent.'').
\94\ MAP-21, Division C, Title I, ``MOTOR VEHICLE AND HIGHWAY
SAFETY IMPROVEMENT ACT OF 2012.''
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In addition, the Safety Act gives NHTSA the discretionary authority
to issue safety standards to address specific safety needs, provided
that the standard is objective, practicable, and appropriate for the
type(s) of vehicles to which it applies.\95\ NHTSA has concluded that
requiring a rear seat belt warning system equipped with occupant
detection be able to detect unbelted children smaller than the size
represented by the 5th percentile female crash test dummy meets a
safety need and is practicable and appropriate.
---------------------------------------------------------------------------
\95\ 49 U.S.C. 30111.
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Specifying occupant characteristics corresponding to a 5th
percentile female would not address rear seat belt usage by children
because the vast majority of children are smaller than the 5th
percentile female test dummy. The population of children seated in the
rear who should be restrained with a seat belt is comprised of children
seated in a booster seat and children who have transitioned out of a
booster seat to sit directly on the vehicle seat. As we explained in
the NPRM, children typically begin sitting in a booster seat
(transitioning out of a forward-facing CRS) around 4-7 years old
(depending on the height and weight of the child and the respective
limits of their forward-facing car seat). Children typically transition
out of a booster seat between the ages of about eight and thirteen
(again, exactly when depends on the child's height and weight). The
Hybrid III 5th percentile female crash test dummy weighs 108 lb (50
kg). This weight corresponds (approximately) to a 50th percentile
fourteen-year-old girl and a 50th percentile thirteen-and-a-half-year-
old boy.\96\ This means that if
[[Page 411]]
NHTSA were to specify criteria matching the 5th percentile female, it
would essentially be ignoring a large percentage of children ages 6-14,
and likely some 15-18 year old children with weight lower than that of
a 5th percentile female. That is, if NHTSA specified the 5th percentile
female, the rear seat belt warning requirements would only be targeting
older children, not younger children.\97\ This disparity strongly
suggests that NHTSA should specify a smaller occupant for testing if
doing so would be practicable.
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\96\ Center for Disease Control Growth Charts for Children 2-20
years of age: Boys Stature-for-age and Weight-for-age percentiles
and Girls Stature-for-age and Weight-for-age percentiles, published
in May 2000 (modified in November 2000) and available at https://www.cdc.gov/growthcharts/data/set1clinical/cj41c022.pdf and https://www.cdc.gov/growthcharts/data/set1clinical/cj41c021.pdf,
respectively. (last accessed September 10, 2024).
\97\ A booster seat augments the total weight on the rear seat.
However, as we explained in the NPRM--and as we adopt in this final
rule--we will not be testing with a booster seat because we are
aware that children can be prematurely transitioned to a seat belt
without the use of a booster, and we believe it is desirable to test
the lower end of the possible weight range that encompasses children
that could conceivably be restrained with a seat belt alone. We
discuss the issue of booster seats in our discussion regarding
feasibility later in this section.
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Although NHTSA has concluded that specifying occupant
characteristics matching those of a 6-year-old child would meet a
safety need and be fully consistent with MAP-21, MAP-21 directs NHTSA
to issue a final rule only if the rule would meet the criteria set out
in Sec. 30111 of the Safety Act. These criteria include that the rule
be practicable. As noted earlier, the statutory criterion of
practicability is multidimensional (see Section IV. Statutory
Authority). After considering the comments, NHTSA agrees that most
currently deployed rear seat belt warning systems utilizing occupant
detection are not able (or designed) to reliably detect a 6-year-old
occupant. NHTSA also agrees with the commenters who indicated that
there are a number of challenges to rear-seat occupant detection,
related both to false negatives and false positives. However, while
many or most currently deployed rear occupant detection systems used
for seat belt warnings may not comply with the requirements in the
final rule, we believe that OEMs are capable of improving the
technology and meeting these challenges. Further, NHTSA believes that
selecting a 6-year-old child instead of the 5th percentile female
appropriately balances benefits and costs. We explain this conclusion
in more detail below.
NHTSA believes that while current occupant detection systems might
not reliably detect a 6-year-old child, or a booster seat, such a
requirement is feasible. NHTSA acknowledges the commenters who argued
that many or most rear occupant detection systems that are currently
deployed may not be able to reliably detect a 6-year-old occupant,
either seated directly on the seat or in a booster seat. NHTSA has not
tested current systems to verify or refute this claim, so we have no
firm basis on which to agree or disagree with these comments. NHTSA
has, though, noted that some owner's manuals inform consumers that if
they place lightweight objects (such as a briefcase) on the rear seat,
it may trigger the seat belt warning; this suggests that some rear seat
belt occupant detection systems may be capable of detecting younger
(and therefore lighter) occupants. For example, the owner's manual for
the MY 2024 Cadillac Escalade states that ``[t]he rear passenger seat
belt reminder light and chime may come on if an object is put on the
seat such as a briefcase, handbag, grocery bag, laptop, or other
electronic device. To turn off the reminder light and/or chime, remove
the object from the seat or buckle the seat belt.'' \98\ In most cases
the weights of these listed items would be less than the weight of a 6-
year-old. Furthermore, we understand (although again, have not been
able to verify) that at least one manufacturer's system may be able to
detect a 6-year-old not in a booster.\99\
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\98\ Page 114. As another example, the owner's manual for the MY
2024 Tesla Model Y states: ``If all occupants are buckled up and the
[seat belt] reminder stays on, . . . remove any heavy objects (such
as a briefcase) from an unoccupied seat.''
\99\ NHTSA is not disclosing further details about this finding
because this information is confidential.
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We also acknowledge that some rear-seat occupant detection systems
may not be able to reliably classify a young child seated in a booster
seat as an occupant. We explained in the NPRM that children start using
belts (with a booster seat) at about 6 years old, and typically
transition out of a booster seat around 8 to 13 years old. We
acknowledge, as IEE commented, that some rear detection systems may not
simply classify objects/occupants based on weight, but may also base
the classification on other information, such as the pressure profile,
so that a child seated in a booster seat may not be classified as a
human occupant, regardless of the child's weight and height. We
recognize that manufacturers would have to develop a solution to this
issue. We also acknowledge other issues pointed out by the commenters
that make accurate detection a challenge, such as out-of-position
children.
Nevertheless, we believe that it is feasible to develop this
technology. We agree with IEE that more advanced technologies (such as
radar sensors) are not yet proven. However, occupant detection
technology similar to that used for advanced air bag testing in the
front that is used to detect different sized dummies in different test
scenarios,\100\ including 6-year-old dummies, could potentially be
reprogrammed to address our occupancy criteria needs and this would
also address the comments about not being able to detect children in
boosters. Testing with a 6-year-old should also be compatible with the
requirements in ECE R16 and Euro NCAP; if a system can recognize a 6-
year-old occupant, it should also be able to recognize an occupant with
the characteristics of the 5th percentile female. Moreover, to give
manufacturers flexibility, we have kept the requirements as technology-
neutral as possible in order to facilitate innovation. We acknowledge
that requiring an occupant detection system to meet the final
requirements when tested with a dummy or human representing a 6-year-
old could increase the cost of the system and may take some time to
implement and test, but again, the final rule does not require occupant
detection. We are also providing two years of lead time, so current
occupant detection systems could be offered until then (See Section IX,
Compliance Date).
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\100\ The Advanced Air Bag rule was targeted at protecting all
individuals from potential harm from air bags; specific requirements
were included that were targeted at protecting children. See Section
VI.A.2.a.1.
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With respect to the comments on cargo (or pets) leading to false
warnings based on the relatively low weight specification for the
occupancy criteria, while this is a potential issue, we believe that it
is mitigated in a variety of ways. First, potential consumer annoyance
should be mitigated by the relatively short duration of the warning (60
sec) and the fact that it does not have an audible component. The
weight of the types of objects typically placed on the rear seats (such
as briefcases, water bottles, and groceries) would also likely be well
under the weight of a 6-year-old (46.5 lb).
There may also be technical solutions to mitigate false warnings.
Several comments referred to complications with detection related to
the weight of the occupant or object placed on the seat. However,
occupant detection technology reliant solely on weight-based sensors
may not necessarily be the only technology solution to meet the
performance requirements in this final
[[Page 412]]
rule. We also note that, based on the comments alone, it appears that
there are presently issues with false alarms for current systems which
are presumably based on detecting a 5th percentile female occupant.
(However, no specific data were provided on the performance of these
systems with relation to false warnings or how such false warnings have
affected acceptance.)
If technical solutions to mitigating any remaining consumer
acceptance concerns are not readily available, NHTSA continues to
believe the behavioral solutions we suggested in the NPRM (such as
placing objects on the floor instead of the seat, or buckling the belt
if cargo is placed on the seat) are viable. Although Honda and HATCI
did not believe such behavioral solutions were viable, as noted
earlier, at least some manufacturers are already providing such
guidance in the owner's manual. We acknowledge that there may be some
trade-off in effectiveness if consumers frequently buckle the belt when
cargo is placed on the seat or become accustomed to ignoring the
warning. (We are not aware of any data or research on such trade-offs.)
Nevertheless, we believe that this concern would not meaningfully
affect the warning's effectiveness, and that any lessening in
effectiveness should be offset by the system being able to detect the
full range of occupants that should be using a seat belt.
With respect to interactions between the occupant detection system
and CRSs, we agree with the commenters that the final rule should not
require that the occupant detection system be able to detect a forward-
or rear-facing CRS installed with LATCH. We agree with Freedman and
Honda that the easiest and most effective solution to avoid false
warnings for LATCH-installed CRSs is to continue recommending the seat
belt be fastened behind the CRS. We encourage this practice on our
website \101\ and some manufacturers are already providing consumers
with this guidance.\102\
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\101\ See www.nhtsa.gov/road-safety/child-safety (last accessed
May 16, 2024).
\102\ For example, the owner's manual for the MY 2024 Subaru
Forester advises the consumer that ``[t]he seatbelt warning system
of the rear seats detects if any of the seats are occupied by a
passenger. Installing a child restraint system in the rear seating
area, using the LATCH anchors, may result in the activation of the
passenger seatbelt warning light and chime. Fastening the rear
seatbelt prior to installing the child restraint system will avoid
activating the passenger seatbelt warning light and chime.''
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NHTSA also considered the relative costs and benefits of specifying
a 6-year-old child as opposed to the 5th percentile female. In
particular, we considered some commenters' assertions that specifying
the 6-year-old would discourage manufacturers from adopting systems
with occupant detection or would force manufacturers to downgrade their
systems to the positive-only option (which did not require occupant
detection). We have concluded that specifying a 6-year-old as opposed
to the 5th percentile female appropriately balances costs and benefits.
There are several reasons for this conclusion.
First, and most important, a system that does not monitor child
occupants smaller than a 5th percentile female does not monitor the
entire population of children who can and should be using seat belts.
As we noted above, the height and weight of the 5th percentile female
dummy correspond, approximately, to that of a 14-year-old. Because the
5th percentile female dummy would not represent most younger children,
the system would not work accurately for these children. This is
especially worrisome given that children 12 years old and younger
represent more than half of the rear seat occupant population.\103\
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\103\ See https://www.nhtsa.gov/crashworthiness/child-safety-
crashworthiness-
research#:~:text=Since%20children%2012%2Dyears%2Dold,booster%20seats%
20and%20seat%20belts (last accessed May 16, 2024).
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Accordingly, specifying the 5th percentile female could result in
unbelted child occupants in the rear not benefiting from the seat belt
warning. For instance, if a negative-only system with occupant
detection did not detect an unbelted child smaller than the 5th
percentile female seated in a rear seat, the visual warning would not
indicate an unbelted occupant at an occupied seat (e.g., for systems
with a pictogram that indicates which seat are not in use, the
pictogram would likely display something like a ``grayed-out'' seat to
indicate that the system was registering a seat as unoccupied). In this
scenario, the driver may not realize that the system was not detecting
the child occupant and may think the child is buckled when they are
not. This concern is not hypothetical. The owner's manual for the MY
2024 Subaru Forester states that ``[t]he driver must check that all the
passengers have fastened their seatbelts properly since the seatbelt
warning system may not detect passengers under the following
circumstances.--When cushions or child restraint systems, etc., are
used--When a child or small adult is sitting in the seat.'' The fact
that the system does not work for some classes of occupants could also
lead the driver to be less likely to respond to accurate warnings.
These shortcomings could also affect consumer acceptance of the system.
Second, the concern about downgrading to a positive-only system is
alleviated because we have modified the proposal so that the final rule
does not dictate specific compliance options for the information
conveyed by the visual warning; the finalized requirements for the
visual warning allow all of the systems that would have been allowed
under the proposed rule, as well as additional systems that would not
have been allowed under the proposal.
Third, a very small percentage of vehicles currently sold in the
U.S. is equipped with rear-seat occupant detection. Based on the 2022
NCAP data, approximately seven percent of light vehicles have SBWS with
occupant detection for the rear seats. Relatedly, rear systems with
occupant detection are a relatively new feature in the U.S. vehicle
market. So even if some manufacturers were to stop offering occupant
detection, it would affect a relatively new feature on a small fraction
of vehicles offered for sale in the U.S. and would not be a meaningful
reduction in the choices presently offered to consumers.
Fourth, this trade-off may or may not materialize. The trade-off
would not occur if manufacturers develop and deploy rear-seat occupant
detection systems capable of detecting a 6-year-old within the allotted
lead time (two years).
Fifth, the possibility that some manufacturers may choose to forgo
occupant detection because the final rule specifies the 6-year-old does
not lead us to conclude that it would be preferable to specify the 5th
percentile female. We considered the relative benefits and costs of
specifying each of these systems.
The target population addressed by this rule will necessarily be
larger if we specify the 6-year-old--and, importantly, this addition to
the target population consists of children. Due to a lack of data, the
FRIA was unable to establish how much more effective a rear seat belt
reminder system with occupant detection would be relative to a seat
belt reminder system without occupant detection. However, it is
important to note that the baseline seat belt use rate for rear seat
occupants ages 6 to 10 years is already very high. As it is unlikely
that the seat belt use rate would reach 100 percent, this leaves very
little room for improvement. Accordingly, the children who will benefit
from the rule if we specify the 6-year-old is effectively children from
about ages 11-18. This is still a larger
[[Page 413]]
target population than if we specified the 5th percentile female.
Targeting this population points towards greater benefits.
On the other hand, if NHTSA specifies the 6-year-old, at least some
manufacturers may offer fewer rear seat belt reminder systems with
occupant detection. However, we are unable to estimate the overall
impact of this potential reduction because of several unknowns: how
many fewer systems with occupant detection will be offered; the
difference in effectiveness between systems with occupant detection and
systems without occupant detection; \104\ and the seat belt use rates,
injuries, or fatalities for children ages 11-18.\105\ We also believe
that any short-term decrease in net benefits (if that should in fact
materialize) is outweighed by what we anticipate to be the greater
benefits in the medium-to-long term for children. Moreover, specifying
the 6-year-old would result in seat belt reminder systems that are able
to reliably inform the driver of unbelted children in the rear seat.
While our regulatory analysis is not able to quantify these benefits to
an especially vulnerable occupant population, we recognize the
importance of these unquantified benefits. NHTSA therefore concludes
that specifying the 6-year-old appropriately balances benefits and
costs compared to specifying the 5th percentile female.
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\104\ The NPRM explained that while the main advantage is more
informative warnings and that it can reduce false warnings for
unoccupied seats, it can also (as pointed out by some commenters)
result in false warnings.
\105\ Because of data limitations, NHTSA was unable to break out
this information for this age group specifically. NHTSA was only
able to segment the analysis into occupants ages 6-10 and occupants
11 and older.
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v. Duration
NHTSA proposed that the start-of-trip warning last for at least 60
seconds. We believed that 60 seconds would be sufficient to capture the
driver's attention and appropriately balanced effectiveness and
acceptance.
60 seconds is a shorter warning than we proposed for the front
outboard seats. There were a couple of reasons for our tentative
decision that a shorter warning is warranted for the rear seats. First,
we did not propose to require occupant detection for the rear seat belt
warning system; the positive-only compliance option would require that
the driver be informed of which rear seat belts are fastened. This type
of ``warning'' functions more to provide information to the driver,
rather than a true warning (because it will be providing information to
the driver even if all rear occupants have fastened their seat belts),
so we tentatively believed that it is not necessary to require that it
be particularly long-lasting. Second, and related, even for the
compliance options that would entail occupant detection, the
complexities of occupant detection in the rear seats and the
possibilities for false positives provide another reason for not
requiring an extremely long-lasting warning. Manufacturers would be
free to provide a longer warning.
This duration was consistent with ECE R16, Euro NCAP, and the IIHS
protocol, each of which requires a visual warning at the start of the
trip for the rear seat belts lasting at least 60 seconds. It is also
consistent with many of the rear seat belt warning systems currently
deployed in the United States. In the NPRM we noted that, of the
fifteen manufacturers that provide vehicle models with a rear seat belt
warning system in the United States, eight appeared to provide systems
with initial visual warnings that are active for at least 60 seconds.
An additional three manufacturers appeared to provide visual warnings
until the seat belt is fastened.
Comments
Auto Innovators, Freedman, Honda, HATCI, and Consumer Reports
supported a 60-second minimum requirement. Auto Innovators and HATCI
commented that this requirement would align with ECE R16.
SRN requested a longer-duration warning requirement. It argued that
the proposed warning would be only moderately effective (especially for
occupants of rideshare vehicles) because it could be easily ignored.
SRN also commented that caregivers, who may have children in car seats
and boosters, may need more time to interpret the warning. SRN also
suggested that a seat belt status indicator could be valuable as a
constant readout on the dashboard, as warning lights are sometimes
dismissed or ignored.
Agency Response
The final rule adopts the proposed 60-second minimum duration. We
believe this requirement appropriately balances effectiveness and
acceptance. A 2015 survey of drivers of vehicles with RSBWSs found that
28 percent of GM drivers noticed an increase in rear seat belt usage,
and 23 percent of Volvo drivers reported an increase in rear seat belt
usage.\106\ The GM system used a 30-second visual warning at start-up
and the Volvo system provided a short message at start-up, suggesting
that a 60-second warning would be at least as effective. The 60-second
minimum duration also harmonizes with ECE R16, Euro NCAP, and the IIHS
protocol.
---------------------------------------------------------------------------
\106\ Paul Schroeder & Melanie Wilbur, Survey of Principal
Drivers of Vehicles with a Rear Seat Belt Reminder System.
Washington, DC: National Highway Traffic Safety Administration
(2015).
---------------------------------------------------------------------------
A longer warning then 60 seconds could be annoying (in particular
for systems without occupant detection that display unfastened belts).
We also believe that 60 seconds is long enough to interpret the
warning. This is what some current systems use, and we have no
information to suggest that consumers have had difficulty interpreting
the warning. This is a minimum performance requirement so manufacturers
may voluntarily provide warnings lasting longer than 60 seconds. On the
other hand, we are aware of vehicles that provide shorter warnings, so
having a 60-second requirement will ensure a minimum level of
performance.
vi. Other Aspects
NHTSA also received comments on other aspects of the proposed rear
seat belt warning requirements.
Comments
Tesla requested that NHTSA clarify whether the ``rear rows''
reference includes all designated rear seating positions. Tesla also
commented asking if the agency had a plan to also address integrated
child seats that have seat belt reminder technology. Auto Innovators
commented that the proposed S7.5(c)(1)(ii), requiring a visual and
audible change of status warning, and S7.5(c)(2)(ii), prohibiting a
visual warning that a seat belt is not in use for an unoccupied seat,
are inconsistent and require clarification.
Agency Response
The final rule retains the reference to ``all rear designated
seating positions.'' The proposed regulatory text did not refer to
``rows''; it simply referred to ``rear designated seating positions.''
Accordingly, it applies to all rear designated seating positions in
applicable vehicles.
It is not necessary that the rule specifically address integrated
child seats. Integrated child seats are CRSs or booster seats that are
built into the vehicle seat. A child seated in an integrated child seat
is secured with either a seat belt or a harness. If the child is
secured with a seat belt, then the seat belt warning should monitor
belt use as with any seat belt. If the child is secured with a harness,
the seat belt reminder would not be required for the harness, because
children in an integrated seat with a harness are not part of the
target population for this rule
[[Page 414]]
just as children in rear- and forward-facing CRSs are not part of the
target population. In addition, we were unable to identify any new
vehicles with integrated child seats that use a harness. Integrated
booster seats would not pose an issue for the seat belt warning system,
and we are aware of only one vehicle manufacturer that offers
integrated booster seats on some vehicles as an option.\107\ Regarding
Auto Innovators comment, the final rule does not include the proposed
requirement that the warning is not permitted to indicate a seat belt
is not in use for an unoccupied seat because we do not believe this is
necessary.
---------------------------------------------------------------------------
\107\ See https://www.volvocars.com/lb/support/car/xc90/article/3212aabb4f810a77c0a8015146e81cc9 (last accessed May 16, 2024).
---------------------------------------------------------------------------
b. Audio-Visual Change-of-Status Warning
NHTSA proposed requiring an audio-visual warning when a rear seat
belt is unbuckled during a trip. We proposed that an audio-visual
warning must activate when the ignition switch is in the ``on'' or
``start'' position, the vehicle is in forward or reverse drive mode,
and the status of the seat belt changes from in use to not in use,
unless any rear door is open, in which case a change-of-status warning
would not be required. The exception for an open rear door was intended
to allow for passengers to exit the vehicle when the driver does not
shift into park without activating the change-of-status warning.
The audio-visual warning would have to last for at least 30 seconds
or until the seat belt that triggered the warning is in use. We
proposed that the audible signal may be ``intermittent'' (i.e., not
continuous), which mirrors the longstanding requirements for the
driver's seat belt warning. If intermittent, we proposed that inactive
periods longer than three seconds would not be counted toward the total
minimum duration of the audible warning. Because the required minimum
duration was relatively short, we did not propose additional audible
signal characteristics, such as a duty cycle. (In contrast, we proposed
additional signal characteristics for the front seat belt change-of-
status warning because of the required longer duration for that
warning. The final rule decisions on these aspects of the front seat
warning are discussed in Section VI.B.3).
ECE R16 similarly specifies an audio-visual change-of-status
warning for rear seats. Specifically, if a fastened belt becomes
unfastened when the vehicle is in ``normal operation'' (defined as
forward motion at a speed greater than 10 km/h (6.2 mph)),\108\ ECE R16
specifies an audio-visual warning (second level) when certain distance,
time, and/or speed threshold(s) (at the choice of the manufacturer) are
exceeded.\109\ The additional thresholds are distance traveled (not to
exceed 500 meters), vehicle speed (not to exceed 25 km/h (15.5 mph),
and/or travel time (not to exceed 60 sec). This warning must last for
at least 30 seconds unless the unfastened belt becomes fastened, the
seat associated with the unfastened belt is no longer occupied, or the
vehicle is no longer in normal operation.\110\ This warning may not be
canceled by the driver.
---------------------------------------------------------------------------
\108\ Section 2.47.
\109\ Section 8.4.3.3 (front seat belts) and section 8.4.4.5
(rear seat belts).
\110\ These summaries simplify the requirements somewhat. They
will be discussed in greater detail later in the preamble where
relevant.
---------------------------------------------------------------------------
Euro NCAP also requires (to earn points) an audio-visual change-of-
status warning at vehicle speeds of 25 km/h (15.5 mph) and above.\111\
If the change of status occurs below 25 km/h (15.5 mph) and no doors
are opened, the signal may be delayed until the vehicle has been in
forward motion for 500 meters or has reached a forward speed of 25 km/h
(15.5 mph).\112\ A warning is not required if the system has occupant
detection as long as all doors remain closed and the number of buckled
positions remains the same, in order to minimize the number of false
positives (e.g., children remaining in the vehicle but swapping seats
in the rear while at a traffic light).\113\ The warning duration
differs for the visual and audible warnings. With respect to the visual
warning, if the system does not have occupant detection, the warning
must last until the seat belt is fastened or 60 seconds have
elapsed.\114\ If the system does have occupant detection, the signal
must remain on until the belt is fastened. The audible warning must
last until the belt is fastened,\115\ 30 seconds have elapsed,\116\ or
the vehicle speed falls below 10 km/h (6.2 mph).\117\
---------------------------------------------------------------------------
\111\ Section 3.4.1.5.
\112\ Section 3.4.1.5.
\113\ Section 3.4.1.5.
\114\ Section 3.4.3.1.1.
\115\ Section 3.4.1.6.
\116\ Section 3.4.3.2.
\117\ Section 3.4.1.6. The audio signal must resume when the
speed goes above 25 km/h (15.5 mph) and no doors have been opened
and the seat belt(s) remain unbuckled. In addition, the audible
signal may instead meet the requirements for the front seating
positions, if the vehicle is equipped with occupant detection.
---------------------------------------------------------------------------
ECE R16 \118\ and Euro NCAP \119\ do not count periods in which the
warning stops for longer than three seconds as part of the overall
duration.
---------------------------------------------------------------------------
\118\ Section 8.4.2.4.1.
\119\ Section 3.4.3.2.3.
---------------------------------------------------------------------------
The IIHS protocol also requires an audio-visual change-of-status
warning lasting at least 30 seconds when the vehicle is in motion. The
exact trigger depends on vehicle speed. When vehicle speed is between
10 and 40 km/h (6.2 and 24.9 mph), the audio-visual warning must start
within 30 seconds of continuous forward motion, and when the speed
exceeds 40 km/h (24.9 mph), the audio-visual warning must begin within
two seconds if the signal has not already begun. The warning can
deactivate when the seat belt that triggered the warning is fastened;
the vehicle is no longer in forward motion above 10 km/h (6.2 mph); or
the seat or seats that triggered the warning are no longer occupied.
Similar to Euro NCAP, the thresholds to trigger the primary audible
signal and visual signal may be reset if any doors have been opened
when the vehicle is not in motion.
The proposal differed from ECE R16, Euro NCAP, and the IIHS
protocol in some respects. The proposed 30-second duration was shorter
than the 60-second duration for the visual signal specified in Euro
NCAP, but consistent with the 30-second duration for the audible
signal. We also did not propose any speed, distance, or time triggers.
And we did not propose the Euro NCAP allowance for not requiring a
change-of-status warning when all doors remain closed and the number of
buckled positions remains the same because it would require a delay in
the activation of the change-of-status warning; also, these types of
events are likely uncommon and require very little time to complete, so
exposure to the warning would be very limited.
Comments
Consumer Reports agreed with the agency's decision to require the
change-of-status warning to include both audible and visual components.
It also supported departing from ECE R16 and Euro NCAP and requiring a
warning whether or not a vehicle is in motion because a stopped vehicle
presents the best opportunity for the driver to ensure that the
occupants are belted.
On the other hand, Honda, Nissan, NADA, Tesla, Ford, Auto
Innovators, and HATCI commented that reminder trigger conditions should
harmonize with ECE R16 and/or Euro NCAP and be based on vehicle motion.
Auto Innovators and Honda commented that the proposed requirements for
providing an audible alert may result in widespread consumer acceptance
issues. For example, Auto Innovators argued that establishing a trigger
[[Page 415]]
threshold based solely on the ignition being on, absent vehicle motion,
will result in scenarios where an unbelted condition that may otherwise
be viewed as reasonably acceptable would result in an audible alarm,
including those where the vehicle is either stopped (and in drive) or
slowing in anticipation of an upcoming stop (e.g., in a rideshare
scenario or school drop-off). Auto Innovators recommended that NHTSA
harmonize with ECE R16, which requires the audio-visual warning to be
provided only when there is a change in seat belt status when the
vehicle is traveling above 25 km/h (15.5 mph) or moving below 25 km/h
(15.5 mph) for a period of 60 seconds.
Auto Innovators further commented that the agency did not
articulate why it has proposed that an audible alert occur when the
vehicle is in reverse. Auto Innovators explained that such maneuvers
are typically low-speed events, and that the agency has not provided
clear justification for why an audible alert is needed in these
scenarios.
Honda commented that if NHTSA does not adopt a speed threshold, it
could consider an alternative approach that would allow a single chime
when the change of status occurs (assuming the vehicle is stationary)
and then resume the full alarm when the vehicle begins moving. Honda
commented this modification would minimize intrusive and annoying
alarms, ensuring that the system still provides a warning but does not
cause excessive consumer annoyance.
We also received comments both in support of the proposed warning
duration, as well as comments that recommended alternative durations.
Auto Innovators, HATCI, and Honda support the proposed 30 second
duration and harmonizing with ECE R16. Tesla encouraged harmonizing
with either ECE R16 or Euro NCAP.
Some commenters favored a longer minimum duration. Freedman argued
that the audio warning should be the same as that for the driver seat
(indefinite). Consumer Reports commented that the warning should last
at least 60 seconds unless the belt is buckled, to be consistent with
the start-of-trip visual warning. Ms. Cross proposed requiring at least
a 90 second minimum duration, pointing to, for example, consumer
surveys showing that many consumers favor persistent warnings.
Honda and Auto Innovators recommended that NHTSA allow the change-
of-status warning to cease if a different belt is buckled (and the
total number of buckled seats is restored) to allow the driver to
recognize that a rear occupant has changed seats and refastened the
belt.
Tesla requested that NHTSA define the start time to measure the 30
seconds duration. Tesla further commented that if the warning continues
after the seat belt is fastened, it may lead to a potential confusion
on system functionality, which could lead to occupants ignoring future
warnings.
Agency Response
In response to the comments, the final rule adds a provision to
accommodate occupants switching seats. However, we are declining to
adopt additional trigger conditions, such as a speed criterion. The
final rule also includes the proposed 30-second duration. Our reasoning
for these and other choices is detailed below.
The final rule includes the proposed exception from activation when
a rear door is opened, i.e., for a drop-off scenario: a change-of-
status warning is not required if a rear passenger unbuckles and exits
the vehicle. However, the final rule omits the additional proposed
language that ``the system may consider this situation as a new trip
with respect to that seat belt and reset the warning system.'' This
language is vague and superfluous. The exception is based on the door
opening, and there is no need to permit the system to ``reset'';
manufacturers can program the system logic for the state of the system
after a belt is unfastened and a door is opened as they deem
appropriate, as long as the system complies with the finalized
requirements.
The final rule implements the recommendation from Auto Innovators
and Honda to follow Euro NCAP and allow the change-of-status warning to
deactivate if the system is able to recognize passenger(s) switching
seats when all the doors are closed and the number of buckled positions
remains the same. This change would limit the exposure to the warning
if the occupant(s) changes seats and refastens the belt in another
seat. Without this allowance, the warning would remain activated when
all occupants were belted and would be unnecessarily annoying. This
condition will also accommodate situations where a passenger buckles
into a wrong buckle and corrects it. The additional regulatory text is
based on Euro NCAP.\120\
---------------------------------------------------------------------------
\120\ Section 3.4.1.5 (``Where the system is able to track the
number of buckled positions in the rear, no change of status signal
(for the rear seats) is required as long as all doors remain closed,
and the number of buckled positions remains the same. This is to
minimize the number of false positives (ex: children remaining in
the vehicle but swapping seats in the rear while at a traffic
light.'')).
---------------------------------------------------------------------------
However, we are declining to add the additional requested trigger
conditions, or to simply require a single chime when a change of status
occurs because, as we explained in the NPRM, seat belts provide a
safety benefit even at lower speeds, and regardless of the direction of
motion. We also believe a warning would be beneficial even if the
vehicle is not moving. A driver may want to know if any rear seat
occupants--especially children--have been unbuckled while the vehicle
is temporarily stopped (e.g., at a traffic light) or slowed (e.g., in a
parking lot), because the vehicle could soon be resuming travel. In
addition, providing a warning when the vehicle is stationary would
allow the driver to attend to the unbuckled passengers before having to
focus attention on the driving task. We similarly believe that a
warning would be useful before the vehicle has reached any distance or
trip time threshold. The final rule also includes the reverse driving
mode as a trigger as proposed. We believe this trigger is beneficial
because it will require a warning before a vehicle begins driving on
the road (e.g., before pulling out on to the road). We believe the
benefits of having a warning activate in these circumstances outweighs
the potential drawbacks identified by the commenters (for example, when
the vehicle is stopped and the belt is unbuckled before a door is
opened). In addition, we have eliminated the condition that the
ignition switch be in the ``on'' or ``start'' position because it was
redundant with the condition that the vehicle be in a forward or
reverse drive mode.
We do not believe that a visual warning alone, without an audible
component, would be sufficient; a change of status is a serious event,
due to the higher risk that comes with riding unbelted, and we believe
this risk warrants a more effective audio-visual warning. In addition,
the relatively short duration of the warning (30 seconds) should help
minimize consumer annoyance in other scenarios that might result in an
unbelted occupant in very low-risk scenarios. We therefore believe that
consumers will accept the warning.
NHTSA is also finalizing the proposal that the audio-visual change-
of-status warning last at least 30 seconds (or until a rear door is
opened). As we explained in the NPRM, this requirement is comparable to
the change-of-status warnings on vehicles currently equipped with rear
seat belt warnings.
[[Page 416]]
While we recognize that longer warnings may be more effective, we are
not requiring a longer warning for the rear change-of-status warning.
This requirement differs from the front seat, for which we are
requiring a visual warning that lasts until the belt is re-buckled and
a speed threshold for the indefinite audible warning. The main reason
we are not requiring a longer rear change-of-status warning is to
mitigate driver distraction. Because the majority of rear passengers
are children, the driver would not necessarily be able to address the
issue immediately and a longer warning could distract from the driving
task.\121\ With respect to Ms. Cross's comment, the survey on consumer
acceptance for rear warnings does not support a specific duration, just
that the majority found the feature acceptable, and the data on the
majority of vehicles having at least a 90 second warning is for the
front seat belt warning at the start of a trip, not a change-of-status
warning, so they are not necessarily directly comparable.
---------------------------------------------------------------------------
\121\ The change-of-status warning does not present the same
concerns with false warnings as does the start-of-trip warning
because the change-of-status warning is not triggered by occupancy.
---------------------------------------------------------------------------
With respect to Tesla's question about start time, the 30-second
clock commences when the trigger conditions specified in the rule are
met. The warning is permitted to stop if the occupant of the seat with
the belt triggering the warning buckles within 30 seconds.
c. Electrical Connections/Removable Seats
In the NPRM we explained that we had tentatively decided not to
propose any requirements with respect to the electrical connections for
folding, rotating, or stowable seats. Because these seats are not
readily removable, the electrical connections should not be disturbed
and could be accommodated with additional wiring. We did, however,
propose two requirements related to the electrical connections for
readily removable seats.
First, we proposed that readily removable seats must either
automatically connect the electrical connections when the seat is put
in place or, if a manual connection is required, the connectors must be
readily accessible. A system using a wireless connection could be
classified as either automatic or manual, depending on whether the user
needs to take any additional actions to establish the wireless
connection when the seat is installed. We agreed with the commenters
who recommended no prescriptive requirements to ensure manufacturers
have flexibility in system design.
Second, we proposed that vehicles using the negative-only
compliance option provide a visual warning to the driver if a proper
electrical connection has not been established for a readily removable
seat because we were concerned that consumers could reinstall removable
seats without making a proper electrical connection. We proposed
requiring a visual warning for negative-only systems only because a
faulty connection would result in the system not triggering any warning
of an unbelted rear seat occupant. Moreover, for a negative-only
system, the driver would otherwise have no reason to suspect that the
system was malfunctioning, and so might mistake the lack of a warning
as an indication that the rear seat occupant was belted. In the NPRM we
explained why we believed that these issues were not present in full-
status or positive-only warning systems.
In the NPRM we stated our belief that both requirements would
mainly affect minivans, which make up a small percentage of the fleet,
but further explained that it might be possible to use the rear seat
belt visual warning signal, with slight modifications (e.g., a
different color) to comply.
Comments
Freedman, ASC, Honda, and Consumer reports commented that they
agree that readily removable seats should not be exempt from the
proposed requirements.
ASC also commented on potential challenges in establishing reliable
electrical connections, explaining that seat belt technology to support
seat belt reminder systems in the field today is contained within an
electrical switch inside the buckle. According to ASC, this
functionality presents two challenges. First, since the removal and
reattachment of the seat will result in disconnecting/reconnecting the
buckle wiring to the vehicle wire harness, the reliability of this
connection needs to be studied to ensure it is robust against
malfunction considering its use case. (RVIA also raised this concern in
its comment.) Second, a user's handling of the electrical interface
presents an opportunity for accidental damage. ASC recommended further
study to determine the robustness of this connection in these systems.
RVIA commented that motor homes are also often equipped with non-
conventional, custom-made rear seating, so that developing wiring and
sensors for the seat belt warning system that are not damaged in the
conversion process from seat to bed would be challenging if not
impossible. RVIA further commented that the NPRM does not consider
convertible seats.
IEE recommended that a visual warning be required for all systems,
not just the negative-only system.
Agency Response
The final rule includes the proposed electrical connection
requirements for readily removable seats. We agree with the commenters
who supported including these requirements that doing so would provide
important safety benefits by helping to ensure that proper electrical
connections are made and the warning system operates correctly, and, in
the case of negative-only systems, warns users that a proper connection
has not been made. We agree with ASC that there is a foreseeable
possibility that users can accidentally damage the system. This risk is
why the final rule requires a warning that alerts the driver if a
connection has not been properly made or if there is a malfunction for
negative-only systems (where there is a risk of the driver not being
aware of the issue).
We acknowledge the potential challenges associated with electrical
connections pointed out by some of the commenters, but we believe the
requirements are feasible. NHTSA's understanding is that removable rear
seats are relatively rare, and typically only installed in the second
row of passenger vans (a very small percentage of the fleet). In the
vehicles in which they are present, it is likely that the seats are not
frequently removed, which would suggest that the electrical connections
would not be exposed to constant removal and re-installation that could
increase the likelihood of damage. Moreover, the fact that the seat is
removable does not necessarily mean that removing the seat means
disturbing the electrical connection. NHTSA is aware of one minivan
model with a rear seat belt reminder and a removable seat (MY 2024
Toyota Sienna Hybrid); in that vehicle, the seat belt anchors--which
contain the wiring necessary for the rear reminder signal to function--
remain in place when the seat is removed, obviating any need to re-
establish any electrical connections when the seat is re-installed.
Furthermore, the technology at issue here is not complex; re-
installing the seats simply would require re-establishing a connection.
If a seat is designed to be removable, it would not be unreasonable to
expect that the seat, when re-installed, continues to have the same
functionality it had before it was
[[Page 417]]
removed. The fact that removable seats are not exempted by ECE R16 or
Euro NCAP strongly suggests that this requirement is not
unreasonable.\122\ Accordingly, we do not believe more study is
necessary to determine the robustness of the connection. Electrical
connections may not be necessary for every removable seat and only a
limited number of vehicles are equipped with removable rear seats. It
is also unlikely that seats are removed and reinstalled frequently.
Therefore, this issue does not appear to warrant further study. In
addition, the requirement for a warning if there is a malfunction also
addresses safety risks associated with potential damage over time.
---------------------------------------------------------------------------
\122\ NHTSA did some limited market research of European models
with removable rear seats. In one (MY 2023 Peugeot 5008) the seat
belt anchors did not appear to be affected by the removal of the
seat. In another (MY 2023 Ford Tourneo Connect), visual indicators
where the seat locks in place were used to confirm proper
installation, but not pertaining to electrical connections
specifically.
---------------------------------------------------------------------------
With respect to RVIA's comment regarding seating specific to motor
homes, such as dinette seating, it is unlikely the requirements apply
to motor home convertible seats. Motor homes not greater than 10,000 lb
GVWR are generally not required to have rear seat belts.\123\ And
NHTSA's regulations exempt motor home seating locations labeled in
accordance with S4.4 of FMVSS No. 207 from being classified as
``designated seating positions,'' so that the seat belt and seat belt
reminder requirements do not apply to motor home seats so labeled.\124\
---------------------------------------------------------------------------
\123\ FMVSS No. 208 S4.2.7.
\124\ 49 CFR 571.3(b) (definition of ``designated seating
position'').
---------------------------------------------------------------------------
The final rule does not expand the connection warning requirements
to systems beyond the negative-only system. As mentioned in the NPRM,
we only think this issue would pose a serious risk for negative-only
systems.
d. Owner's Manual Instructions
NHTSA proposed that the owner's manual (which includes information
provided by the vehicle manufacturer to the consumer, whether in
digital or printed form) describe the warning system's features,
including the location, format, and meaning of the visual warnings. We
also proposed that the owner's manual include instructions on how to
make any manual electrical connections for readily removable seats.
These proposed additions would require a revision to the approved
collection of information in OMB No. 2127-0541.
Comments
We received comments both in support of and in opposition to the
proposed owner's manual instructions.
ASC agreed with the proposal to include information regarding seat
belt reminder systems in the owner's manual instructions. NSC commented
that the owner's manual instructions should include instructions on how
to make any manual electrical connections for readily removable seats,
like child passenger safety seats. NSC urged NHTSA to consider
standardizing generic nomenclature as well as standardizing warning and
icon symbols to reduce driver confusion. SRN requested that
instructions regarding false warnings, such as when relatively heavy
car seats are installed using LATCH, be provided.
Auto Innovators opposed any specific owner's manual requirements,
particularly if the required language is not relevant or applicable to
all vehicles. Auto Innovators commented that the extent to which
guidance may need to be included in the owner's manual is a function of
how the system is designed; if there are certain aspects of the system
design that may require additional instruction, this information should
be provided at the discretion of the manufacturer.
Agency Response
The final rule includes, without any substantive changes, the
proposed owner's manual requirements. We agree that these requirements
will aid in public adoption of the warning systems and help to achieve
their full safety potential. In addition, with increased system
complexity, greater knowledge and understanding of the system is
required. Including detailed information in the vehicle itself is not
practical.
The final rule to some extent standardizes nomenclature by defining
some terms used in the regulation and by specifying requirements for
the visual warning characteristics. However, we attempted to minimize
such requirements to the extent possible to provide manufacturers with
design flexibility. We agree with Auto Innovators not to require
including specific information on how warning systems with occupant
detection function when a CRS is installed with LATCH and guidance on
how to avoid activating the warning (e.g., by fastening the seat belt).
As Auto Innovators points out, the extent of the guidance needed to
potentially limit false warnings depends on the type of system and its
technology and should be left up to the discretion of the manufacturer.
Manufacturers may include language in the child passenger section of
their manuals for further guidance on potential false warnings that is
specific to their system capabilities.
e. Telltale Location
The NPRM proposed that the visual warning signal be required to be
visible to the driver only and not the rear passengers.
Comments
Auto Innovators supported the proposal to provide flexibility for
manufacturers to specify the location of any necessary telltales
related to rear row seat belt use, provided they are visible to the
driver. On the other hand, Freedman commented it would be beneficial
for passengers to see the seat belt status in those vehicles with
multiple rows of rear seats, and indicated that this requirement could
be accomplished with additional monitors in the passenger seating area.
Agency Response
The final rule adopts the proposed requirement that the visual
signal needs to be visible only to the driver. Although we agree with
Freedman that it could be beneficial for rear passengers to see the
warning, we conclude that the increased cost, complexity, and redesign
such a requirement would entail would not be justified. However,
manufacturers would have the flexibility to place the visual warning
where it could be seen by some or all rear seat occupants. In Section
VI.C.7. we discuss the implications of the telltale location as it
relates to automated vehicles. This requirement harmonizes with ECE
R16,\125\ Euro NCAP,\126\ and IIHS,\127\ all of which require that the
rear seat belt visual warning be visible only to the driver.
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\125\ Section 8.4.4.2.
\126\ Section 3.4.1.1.
\127\ Insurance Institute for Highway Safety. (April 2024.) Seat
Belt Reminder System Test and Rating Protocol, Version III, pg. 7.
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3. Alternative Warning Signals
In the NPRM, we noted that the ANPRM had sought comment on
requiring or specifying as a compliance option a rear seat belt warning
that differs from the type of audio-visual warning that is currently
required for the driver's seat belt, such as a haptic warning.
Commenters to the ANPRM generally argued that an alternative warning is
not necessary and that an audio-visual warning would be appropriate.
[[Page 418]]
Comments
We received one comment on this issue. Auto Innovators agreed that
an alternative warning is not necessary in addition to the audio-visual
warnings proposed. However, Auto Innovators commented that
manufacturers should not be prohibited from using alternate warnings
(in addition to the required alerts) if they choose to do so.
Agency Response
We are moving forward with the originally proposed requirements for
audio-visual warnings, while neither requiring nor prohibiting
alternative warning signals. We are specifying minimum performance
requirements to balance the effectiveness and acceptability of these
systems. Manufacturers may go beyond our requirements, such as by
providing a warning on the instrument panel that must be acknowledged
by the driver before any other use of the instrument panel is
permitted. Manufacturers interested in implementing supplementary
alternative warnings signals should take steps to ensure that what is
used will not cause unnecessary confusion or annoyance.
B. Front Seat Belt Warning Requirements
1. Applicability
In the NPRM, NHTSA proposed to require an audio-visual seat belt
warning for any front outboard seating positions in passenger cars, and
all front outboard designated seating positions certified to a
compliance option requiring seat belts in trucks, MPVs, and buses with
a GVWR of 4,536 kg (10,000 lb) or less.\128\ NHTSA also proposed not to
extend the seat belt warning requirements to front center seats.
Additionally, in the NPRM the agency noted that the 2022 automated
driving system (ADS) final rule \129\ also addresses situations where
an ADS-equipped vehicle without manual driving controls has one or no
outboard seats in the front row (e.g., an ADS-equipped vehicle with
only two seats in the front row, one or both of which would be
classified as inboard passenger seating positions under 49 CFR 571.3)
and requires seat belt warnings for certain inboard seats in such
vehicles. We proposed that these front inboard passenger seats have the
same seat belt warnings as front outboard seats. However, although the
proposed regulatory text for passenger cars addressed this ADS-related
applicability issue, the regulatory text for trucks, MPVs, and buses
did not have conforming revisions.
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\128\ There are some compliance options for certain trucks and
MPVs that permit passive protection in lieu of seat belts at the
front outboard seating positions. See FMVSS 208 S4.2.3 (compliance
options for trucks and MPVs weighing between 8,500-10,000 lb);
S4.2.6 & S4.2.1.1 (compliance options for walk-in van-type trucks
and vehicles designed to be sold exclusively to the U.S. Postal
Service 8,500 lb and less).
\129\ 87 FR 18560 (Mar. 30, 2022).
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ECE R16 requires a warning for seats in the same row as the driver
in passenger vehicles up to 5 tons (~11,000 lb) and vehicles used for
carrying goods (e.g., pick-up trucks, vans, commercial trucks) up to 12
tons (~26,000 lb).\130\ Euro NCAP awards points for warnings for all
front row seating positions.
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\130\ Section 8.4.1.1. ECE R16 requires seat belt reminders in
vehicle categories M (passenger vehicles) and N (vehicles carrying
goods). Category M vehicles have a maximum mass of 5 tons
(approximately 11,000 lb) and category N vehicles have a maximum
mass of 12 tons (approximately 26,500 lb).
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Comments
Several commenters, including Consumer Reports, Ms. Freeman, Honda,
Tesla, Mothers Against Drunk Driving (MADD), and Ms. Tombrello
commented in support of requiring an audio-visual seat belt warning for
front outboard passenger seats. Consumer Reports commented that most
manufacturers already implement audible warnings for front outboard
passenger seats that last more than eight seconds, and they agreed with
updating the requirements to reflect marketplace changes that have
resulted in more substantial audible warnings. Ms. Tombrello emphasized
the value in mandating this technology to cover the remaining vehicles
that have not yet incorporated it.
IEE commented that NHTSA should consider mandating a seat belt
reminder warning for the front row seats of vehicles with a GVWR beyond
10,000 lb. IEE indicated that such vehicles are included in ECE R16,
and it would be a safety relevant gain to cover the whole vehicle
fleet. They also noted that ECE R16 includes some exemptions, such as
foldable seats in entry areas of coaches, that could also be
incorporated.
Ms. Tombrello, MADD, Advocates and Public Citizen, and IEE
supported extending the requirements to the front center seating
position. Ms. Tombrello noted the high percentage of center-seat
fatalities that were unrestrained and stated that many children may be
seated in the front center seat. IEE commented that even with a
possibly still negative cost-benefit analysis, NHTSA should consider
including the front center seat because the market share of vehicles
with front center seats can be expected to increase as EVs no longer
have a transmission tunnel. IEE also noted that because ECE R16
includes the front center seating position, established technical
solutions are available.
Agency Response
We are finalizing the applicability of the front seat warning
requirements as proposed in the NPRM, except for a correction to the
regulatory text for certain ADS-equipped vehicles. NHTSA appreciates
IEE's concerns regarding the harmonization and safety benefits that
could be gained by expanding this rule to cover vehicles with a GVWR
over 10,000 lb. However, the agency will not do so in this final rule
because we lack information on implementation cost to support such a
requirement for heavy vehicles. The Safety Act requires that FMVSS be
practicable, which includes appropriately weighting the benefits and
costs of a requirement while ensuring that the standard meets the need
for motor vehicle safety. As we explained in the NPRM, long duration or
indefinite audio-visual warnings are typically appropriate only for
occupied seats due to the nuisance and desensitization effects that
occur when warnings are activated for unoccupied seats.\131\ We also
noted several factors that enabled us to conclude that no cost is
associated with requiring front outboard passenger seat occupant
detection technology in the light vehicle fleet (the vehicles to which
this rule applies). Specifically, light vehicles are covered by the
advanced air bag requirements in FMVSS No. 208, so occupant detection
in the front outboard passenger seat is already widely deployed as part
of the air bag system. Additionally, passenger seat occupant detection
systems are often installed in the light vehicle fleet in part for use
in voluntary seat belt warning systems. Based on compliance and
consumer information submitted to NHTSA, the agency was, and still is,
unaware of any vehicles to which the requirements will apply which do
not already have occupant detection for the front outboard passenger
seating position.
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\131\ 88 FR 61674, 61691 (Sept. 7, 2023).
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However, we do not currently have such information regarding the
heavy vehicle fleet and therefore cannot come to the same (or any)
conclusion about the costs associated with implementation of a similar
requirement for heavy vehicles, so we are not going to extend the
requirements in this final rule. Heavy vehicles are not covered by the
advanced air bag requirements in FMVSS No. 208 \132\ and we do not have
[[Page 419]]
data indicating the market penetration of occupant detection systems
for front outboard passengers in the heavy vehicle fleet in the United
States. Without this or other information indicating the adoption of
occupant detection technology, NHTSA is unable to determine whether
additional occupant detection systems may need to be incorporated into
vehicle designs to support a seat belt reminder system and the
associated cost, and therefore at this time cannot determine that such
a requirement would be practicable. Given the safety problem associated
with a lack of seat belt use in light vehicles, and the availability
and strength of data for systems in light vehicles, delaying this rule
to obtain information for heavy vehicles would not be prudent. Instead,
we are finalizing this rule to cover light vehicles and achieve those
safety benefits quickly. In the future, as more data regarding heavy
vehicles is available, we may choose to extend these requirements.
However, we are not doing so in this final rule.
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\132\ 49 CFR 571.208, S14.
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Additionally, NHTSA is finalizing this rule without a requirement
for front center seats. As we explained in the NPRM, a system for the
front center seat without occupant detection would provide limited
benefit because it would be only a visible and not an audible warning,
the low occupancy of the front center seat, and the limited number of
vehicles in the fleet with a front center seat. In addition, we
estimated that requiring a system with occupant detection for the front
center seats would not be cost effective.\133\ This is discussed
further in Section VIII.B.3 as well as in the docketed FRIA. While EVs
present fewer technical barriers to having a front center seat, we do
not have data suggesting that manufacturers of EVs are incorporating
front center seats at higher rates, or that if they did so, the
requirement would become cost effective.
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\133\ Due to lack of data, NHTSA was unable to establish seat
belt use rates for front center seat passengers under the baseline.
The analysis therefore used the use rates for front outboard
passengers.
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Finally, NHTSA is correcting the regulatory text for trucks, MPVs,
and buses to address the potential for ADS-equipped vehicles that may
have one or no outboard seats in the front row. We discuss other
considerations related to ADS vehicles in Section VI.C.7.
2. Driver's Seat Belt Warning for Light Buses
In the NPRM we proposed to require buses with a GVWR greater than
3,855 kg (8,500 lb) and less than or equal to 4,536 kg (10,000 lb), or
with a GVWR less than or equal to 3,855 kg (8,500 lb) and an unloaded
weight greater than 2,495 kg (5,500 lb), to be equipped with a driver
seat belt warning. This requirement would close a loophole in FMVSS No.
208.\134\
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\134\ In the NPRM, NHTSA mistakenly referred to these vehicles
as ``medium-sized buses.'' This was incorrect. ``Medium-sized
buses'' refers to buses with GVWRs between 10,000 lb and 26,000 lb.
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Comments
Consumer Reports supported NHTSA's efforts to close this regulatory
gap.
Agency Response
NHTSA is finalizing this provision as proposed without change.
3. Visual and Audible Warning Duration and Activation
In the NPRM, we proposed two separate audio-visual warnings for the
driver and front outboard passenger seats. First, we proposed an audio-
visual ``start-of-trip'' warning that must activate when the ignition
switch is placed in the ``on'' or ``start'' position if the seat is
occupied and the seat belt is not in use. This warning would be
required to continue until the seat belt that triggered the warning is
in use. Second, we proposed an audio-visual change-of-status warning
that would be required to activate when the ignition switch is in the
``on'' or ``start'' position, the vehicle is in forward or reverse
drive mode, and the status of the seat belt changes from in use to not
in use. We also proposed that if the change-of-status occurs and a
front door on the same side of the vehicle as the belt triggering the
warning is open, the system can consider that the start of a new trip.
The warning would be required to continue until the seat belt that
triggered the warning is in use. We also proposed that the audio-visual
warning would otherwise not be permitted to activate.
ECE R16 requires a first-level visual warning and a second level
audio-visual warning. The first level visual warning is a start-of-trip
warning that must activate for at least 30 seconds a front seat belt is
not fastened and the ignition is activated. The second-level audio-
visual warning must activate when a seat belt at an occupied seat is or
becomes unfastened when the vehicle is in ``normal operation'' (defined
as forward motion at a speed greater than 10 km/h) and specific
threshold criteria are met (distance traveled, speed, time). The
second-level warning must remain activated for at least 30 seconds,
unless the safety belt is fastened, the seat is no longer occupied, or
the vehicle is no longer in ``normal operation.''
The Euro NCAP specifications are largely similar to those in ECE
R16, with some differences. For example, Euro NCAP requires a longer-
duration ``Loud and Clear'' audible warning (90 seconds) when an
additional speed, time or distance threshold is met. The audio-visual
signal must also immediately deploy if a change of status to unbuckled
occurs at speeds over 25 km/h (15.5 mph). When the change of status
occurs below 25 km/h and the doors are opened, the system may consider
this a ``new journey.'' To prevent unnecessary signals, both ECE R16
and Euro NCAP require that the system be capable of detecting whether
the front passenger seat is occupied.
The IIHS ratings protocol for the initial signal specifies that if
a seat belt at an occupied outboard front-row seating position is
unfastened at ignition and the vehicle achieves continuous forward
motion (at least 10 km/h (6.2 mph)), the audible signal must begin
within 30 seconds when the vehicle speed remains between 10 and 40 km/h
(6.2 and 24.9 mph) and within 2 seconds once the vehicle speed exceeds
40 km/h (24.9 mph), if not already active. For the change-of-status
signal, IIHS specifies the following: If a fastened seat belt at an
occupied outboard front-row seating position is unfastened when the
vehicle's forward motion is between 10 and 40 km/h (6.2 and 24.9 mph),
then the primary audible signal must begin within 30 seconds of
continuous forward motion; if a seat belt at an occupied outboard
front-row seating position is unfastened when the vehicle's forward
motion exceeds 40 km/h (24.9 mph), then the primary audible signal must
begin within 2 seconds if it has not already begun.
In the NPRM, NHTSA proposed to require that the audio-visual
reminder last indefinitely until the belts are fastened (or refastened,
in the case of a change-of-status scenario) at any occupied front
outboard seating position. We proposed that this requirement be both
upon start-up as well as in a change-of-status scenario. We based this
proposal on five reasons that supported our belief that the proposal
would be practicable, objective, and meet the need for motor vehicle
safety. First, the existing requirements are significantly exceeded by
the warnings provided in current vehicles. Second, we tentatively found
(in agreement with IIHS) that the current audible signal duration upper
limit of eight seconds is ineffective for increasing seat belt use.
Third, we tentatively believed that contemporary
[[Page 420]]
consumers would accept a longer warning. Fourth, the technology
necessary to implement such an enhanced warning is already standard
equipment on almost all light vehicles. Fifth, a longer duration would
be consistent with seat belt warning durations required or encouraged
in other markets and ratings programs.
We also sought comment on other duration alternatives, including
those specified in or by ECE R16, Euro NCAP, and the IIHS. ECE R16
requires a 30 second visual warning when the front seat belts are not
fastened and the ignition is activated as well as an audio-visual
warning that must activate for at least 30 seconds if the seat belt
remains unfastened and specific onset criteria are met (e.g., distance
traveled, speed, etc.). The Euro NCAP assessment protocol requires a
visual signal that remains active until the seat belt is fastened, and
a two-stage audible signal; the initial audible signal must not exceed
30 seconds and the final audible signal must be at least 90 seconds.
Under the IIHS ratings protocol, the primary audible reminder signal
for the front outboard seats must be at least 90 seconds in total
duration to obtain an ``acceptable'' or ``good'' rating.
Comments
Duration
NSC, Consumer Reports, and Ms. Freeman supported the proposed
indefinite warning. NSC and GM cited IIHS studies estimating that
audible reminders lasting at least 90 seconds were significantly more
effective for increasing seat belt use than an intermittent audible
reminder and could save up to 1,489 lives annually. NSC also noted IIHS
research that suggests that indefinite and 100 second constant
reminders increased seat belt use by 30-34 percent over an intermittent
reminder. Consumer Reports agreed with updating the requirements to
reflect that the marketplace now accepts more substantial audible
warnings.
Auto Innovators, Mercedes, Honda, NADA, GM, Tesla, Nissan, and
Rivian Automotive (Rivian) opposed the proposed indefinite reminder.
Commenters cited consumer acceptance concerns, and some, such as
Mercedes, Ford, and Auto Innovators, expressed concern that vehicle
owners might seek to circumvent use of the system in various ways. Auto
Innovators also commented that requiring a persistent audible warning
may distract the driver from the driving task and other relevant safety
warnings and may also result in desensitization. Honda noted that these
concerns may lead to consumer backlash if the triggering conditions
fail to accurately target risky situations when trips commence or when
trips are actively occurring.
Auto Innovators commented that the proposal is inconsistent with
the agency's assertions with respect to the rear seat where a 60-second
visual warning would be effective. They argued that 60 seconds is
sufficient to capture the driver's attention and that a longer warning
would have the potential to become distracting or a nuisance.
Commenters suggested a variety of alternative warning durations.
Auto Innovators, Mercedes, NADA, and Nissan encouraged NHTSA to align
the final requirement with the ECE R16 requirement of 30 seconds.
Honda and General Motors both recommended adopting a 90-second
continuous audio-visual warning because it would be the most effective
and is sufficiently persistent to ensure that occupants buckle up.
Honda also encouraged the agency to consider whether adopting a warning
that is continuously active (i.e., 100 percent duty cycle) for a
definite duration of 90 seconds would be as effective as the proposal
to require an indefinite warning with a minimum duty cycle of 20
percent. Honda comments that it believes that a continuous 90-second
chime is sufficiently persistent and might offer greater effectiveness
compared to an indefinite warning that delivers only a 6- second chime
followed by a 24-second pause between chimes. GM cited the IIHS
research mentioned above and an internal research study with the
Virginia Tech Transportation Institute that they stated showed that
even a seat belt reminder chime lasting only approximately 34 seconds
could result in all vehicle occupants in the study buckling their seat
belts.
Tesla and Rivian suggested maintaining the current 4-second
regulatory duration. Tesla noted that longer duration warnings may
increase the risk of distraction if a sensor malfunctions as well as
lead to defeat attempts. Rivian commented that, based on the proposed
triggers, the proposed continuous audible warning would sound in EVs
even if the occupant does not intend to initiate a trip but rather just
sits in the vehicle. It explained that depressing the brake at ignition
places the vehicle in ``Go'' power mode and provides access to the
vehicle's full feature set. As a result, a driver occupying the vehicle
and depressing the brake, even without shifting the vehicle into Drive
mode, would initiate the continuous chime. Rivian suggested that the
current requirement resolves this concern, or alternatively, NHTSA
could allow a manual reset or discontinue feature.
Start-Up Warning Trigger
NADA, Nissan, Auto Innovators, Ford, Mercedes, Rivian, Honda, and
HATCI specifically disagreed with the proposed ignition trigger for the
indefinite warning and argued that it would result in consumer
annoyance.
Some commenters, such as Auto Innovators, HATCI, and NADA,
suggested that the agency should more closely align with the trigger
requirements of ECE R16, which requires a first level visual warning on
start-up but does not require an audible alert to be provided until the
vehicle travels 500 m, the vehicle speed exceeds 25 km/h (15.5 mph), or
the duration time (engine running, propulsion system activated, etc.)
is more than 60 seconds (second level warning). Nissan, Ford, and Honda
urged NHTSA to contemplate harmonization with Euro NCAP and ECE R16 by
including a minimum speed criterion for the trigger.
Mercedes made a similar comment and argued that harmonization would
allow for new seat belt reminder technology/designs to be implemented
faster in the U.S. market. It also commented that it would support
implementing the approach taken in IIHS's protocol, which requires an
audible warning to begin after driving for 30 seconds while exceeding
10 km/h (6.2 mph) or within 2 seconds while exceeding 40 km/h (24.9
mph). Rivian also suggested use of the 10 km/h (6.2 mph) IIHS threshold
for the indefinite audible alert because it largely mitigates low speed
crash concerns. Rivian also noted that this requirement would resolve
concerns with activating the reminder during activation of Auto Hold,
which applies the brakes when the vehicle is stopped even though the
brake pedal is released. Ford supported using a visual warning when the
vehicle is stationary because it offers the best balance of providing
an important reminder before the start of a trip without the potential
annoyance of a persistent audio warning, especially in use cases where
an audio warning is not warranted.
Several commenters, including Nissan, Ford, Auto Innovators, and
Honda, had concerns regarding the proposed triggering conditions when
it comes to consumer acceptance. Honda commented that the start-of-trip
audio-visual warning should be triggered by vehicle motion (or,
alternatively, by the vehicle being shifted into drive or reverse), not
by the vehicle's ignition
[[Page 421]]
being turned on. Honda referred to consumer research suggesting
desensitization regarding the intended purpose of the existing start-up
alarm, which it argued might worsen under the proposed approach. Honda
commented that most individuals do not comprehend why their car chimes
at start-up and that consumers also often incorrectly identify this
chime as being merely a normal start-up sound. Honda argued that an
alarm should sound only when genuine need for the alarm exists.
Honda also requested a clarification, if NHTSA were to retain the
status of the ignition switch as a trigger. It pointed out that as
proposed, the start-of-trip warning ``must activate when the ignition
switch is placed in the `on' or `start' position'' (emphasis Honda's).
Relatedly, the proposed trigger for the change-of-status warning was
tied to the vehicle being in forward or reverse gear. Honda pointed to
a scenario where the driver buckles after turning on the ignition, and
then unbuckles while the vehicle is still in park. In such a case, a
warning would not be required (either start-of-trip or change-of-
status). Accordingly, Honda suggested modifying the logic of the start-
of-trip and/or change-of-status warning to require a warning in this
situation.
A number of commenters, such as Ford, HATCI, and Mercedes, noted
specific consumer acceptance concerns with an ignition trigger in
circumstances where a vehicle has been started but a trip has not begun
or is not going to occur or when a vehicle is going to be travelling at
low speeds. Commenters described situations including: when idling,
waiting for passenger(s), warming up or cooling down a vehicle prior to
a trip (Honda), waiting out inclement weather inside a vehicle, sitting
in a stationary vehicle listening to audio (Honda), and, in the case of
EVs, keeping the vehicle ``ignition'' on for extended periods while
charging to allow use of air conditioning (Mercedes and Honda).
Honda also commented that the proposed trigger is excessively
stringent to meet the safety need and asked that the agency reevaluate
the trigger mechanism to ensure it aligns with safe consumer
expectations and behavior. Auto Innovators commented similarly, noting
that the proposed approach does not meet the need for safety. Auto
Innovators noted customer complaints regarding overly aggressive start-
of-trip warnings that begin on start-up, before the driver even has the
opportunity to put the belt on. Honda argued that crash data illustrate
that crashes at sufficiently low speeds are not likely to lead to
injury, and pointed to data indicating that occupants are highly
unlikely to sustain injuries in crashes occurring below 10 mph. Honda
also argued that speeds below 15 mph are typically not associated with
regular roadway driving. The lowest posted speed limits on residential
or urban roadways in the U.S. are typically set at 25 mph. Speed limits
of 15 mph are more common in non-roadway settings like residential
neighborhoods or parking lots.
Some commenters suggested other alternatives beyond incorporation
of a speed-based trigger. For example, HATCI and Honda suggested a
trigger in which the audible warning begins when the transmission is
placed into a forward or reverse gear. HATCI commented that this
trigger would resolve some concerns with a stationary vehicle pre-trip
or during pick-up and drop-off and for EVs. Auto Innovators posited a
short visual warning as an alternative to an ECE R16 harmonization. It
noted that this approach would be consistent with the IIHS requirements
for front-row seating positions, which also predicate second level
audible alerts based on forward motion of the vehicle. Additionally,
Auto Innovators argued that for the front outboard passenger seat, the
triggering conditions should provide for a delay before a visual
warning is required. Auto Innovators argued that this delay would be
consistent with the proposal to allow for a similar delay for rear row
occupants. It expected that this delay would address challenges in
detecting seat occupancy instantaneously upon ignition.
Change-of-Status Warning Trigger
With regard to the change-of-status warning, commenters generally
supported a requirement but several, including Mercedes, NADA, Honda,
and Tesla, commented that the trigger for the change-of-status warning
should include a minimum vehicle speed. Mercedes and NADA recommended
NHTSA harmonize with the ECE R16 on this issue and require only a
visual warning if the vehicle is stopped or travelling at slow speeds
and incorporate an audio warning if the vehicle is travelling at speeds
of 25 km/h (15.5 mph) or greater. Nissan emphasized that when the
trigger for audio warnings is solely based on gear selection, and these
warnings are activated even when the vehicle is stationary, it has the
potential to be irritating for the occupants, especially in situations
such as being stuck in heavy traffic or waiting in drop-off lines.
Honda commented that using vehicle speed would be more aligned with
safety needs, and that triggering the warning any time the vehicle is
in the drive mode would result in unnecessary alarms for individuals
who are otherwise consistent belt users. Honda commented that this
trigger would reduce acceptance of the system among regular belt users
and desensitize consumers to the alarm. Honda also suggested adding
seat occupancy as one of the activation criteria for the change-of-
status warning to address use cases where an occupant buckles a seat
belt for another seat that is unoccupied, and then unbuckles it.
Nissan and HATCI emphasized consumer acceptance concerns with the
proposed change of-status warning, in particular regarding drop-off.
HATCI noted that the ECE R16 triggers are particularly useful for
addressing these scenarios. It explained that in these drop-off
scenarios, the proposed audible alert would sound until the passenger
opens the door, which could be considered a nuisance to the occupants.
Ford also noted that its vehicles tend to experience frequent ingress/
egress scenarios (e.g., work use of farmers, ranchers or construction
workers) where a persistent warning is not warranted.
Honda suggested that if the agency retains the drive mode trigger
for the change-of-status warning, an alternative could be to use a
single chime when the vehicle speed is below a certain threshold at the
time of unbuckling that becomes a persistent reminder of indefinite
duration once the vehicle resumes motion (if the door remains closed).
Honda argued that if NHTSA believes that a notification is needed, the
single-chime approach would adequately notify the occupants in a non-
intrusive manner.
Mr. Gaal suggested that once a driver or front outboard seat
passenger has unbuckled their seat belt during a trip, a visual change-
of-status warning should immediately appear along with a singular
audible beep, followed by a two-minute gap allowed before the
indefinite audible component of the change-of-status warning occurs
again.
In the NPRM, the agency sought comment on the possibility of
allowing deactivation of the audio-visual system and the situations
under which it would be warranted. While comments on this topic are
discussed more broadly in Section VI.C.6, we note here that a few
commenters, such as Rivian, suggested a manual reset or discontinue
feature as an alternative to a speed-based trigger. Honda, however,
commented that if deactivation requires a complicated procedure, it is
impractical to deactivate nuisance warnings for short trips and
therefore this approach does not effectively mitigate driver annoyance,
[[Page 422]]
especially in comparison to alternative triggers, like vehicle motion.
Honda noted that the use of a motion-based trigger would eliminate the
need for deactivation.
Tesla requested clarification on the definition of ``during the
trip.'' Tesla also asked how the front change-of-status warning is
envisioned to be applied to vehicles in automated mode or full
automation.
Auto Innovators commented that NHTSA proposed unnecessary
restrictions on when an audio-visual warning for a front outboard seat
belt warning system is permitted to activate and requested that they be
removed. It argued that there may be other circumstances, including
those currently unforeseen by the agency, where a manufacturer may seek
to provide a similar audio-visual warning. It also stated that it is
unclear whether these restrictions prevent standardization of the
audible alert used for both front and rear rows.
AVIA observed, with regard to vehicles with automated driving
systems, that the NPRM proposed that the front outboard seats be
allowed to suppress and reset the change-of-status warning only when
the front door being opened is on the same side of the vehicle as the
seat belt triggering the warning. In contrast, the NPRM proposed that
the rear seat belt warning system may suppress and reset the change-of-
status warning when any rear door is opened. AVIA commented that while
this distinction makes sense for a conventional vehicle, some vehicles
with automated driving systems may have interior configurations that
allow for a front outboard occupant to exit through a door that is not
adjacent to their seat. Further, AVIA indicated that autonomous ride
hailing manufacturers or operators may implement safety measures that
only permit the door(s) on a particular side to be opened to encourage
safer egress, even though the door(s) may not be adjacent to the
occupant's seat. AVIA noted that this scenario could lead to a seat
belt change-of-status warning remaining active indefinitely after a
front row occupant exits the vehicle. AVIA suggested the language of
the change-of-status warnings (both front and rear) be updated to allow
the change-of-status warning to be reset when any door designed to
provide egress for the seat is opened.
Agency Response
After considering the comments, NHTSA has decided to modify the
proposed front seat belt warning requirements. The final rule requires
a visual warning whenever a driver or front outboard occupant is
unbelted, and a two-phase audible warning.\135\
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\135\ The final rule also applies to any inboard designated
seating position for which a seat belt warning is required in
S4.1.5.6 (which concerns inboard designated seating positions in
passenger cars without manually operated driving controls).
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The first-phase audible warning is required to activate whenever
the ignition switch is placed in the ``on'' or ``start'' position (or
upon manual activation of the propulsion system, but prior to the
vehicle being placed in ``possible active driving mode'' as defined by
FMVSS No. 305), the seat is occupied, and the seat belt is not in use.
The first-phase audible warning must continue for 30 seconds, until the
seat belt that triggered the warning is in use, until the seat is no
longer occupied, or until the second-phase warning activates, whichever
comes first.
The second-phase audible warning must activate and remain active
when the vehicle speed is equal to or greater than 10 km/h (6.2 mph),
the seat is occupied, and the seat belt is not in use.
Under this approach, there is a start-of-trip audio-visual warning,
with the visual warning lasting until the driver and any front outboard
passenger have fastened their belts, and the audible component lasting
at least 30 seconds (regardless of vehicle speed) and remaining
activated whenever the vehicle speed is 10 km/h or more. Thus, if the
vehicle is on but not traveling at least 10 km/h (6.2 mph), the audible
warning would end after 30 seconds, but would either continue or
reactivate should the vehicle speed reach 10 km/h or more. Similarly,
the final rule requires an audio-visual change-of-status warning, with
the visual warning required to activate and remain activated as long as
the occupant remains unbuckled, and the audible component required to
activate and remain activated whenever the vehicle is traveling at
least 10 km/h.
We are making these accommodations to reduce the potential that
frequent belt users will interact with the audible warning.
Additionally, as explained later in Section VI.C.5 and in the NPRM, we
are specifying a level of audible characteristics, i.e., 30 second
warning cycle, 0.5 Hz chime frequency, and a 20 percent duty cycle,
which we believe will allow manufacturers to optimize for acceptability
while maintaining effectiveness.
This brief summary only gives a high-level overview of the
requirements; the final rule contains additional specifications and
nuances. These, as well as a response to the comments, are covered in
detail below. First, we discuss the audible warning; then we discuss
the visual warning.
Audible Warning Duration
NHTSA has chosen to finalize the indefinite warning (subject to
certain triggers and conditions) because NHTSA has concluded that it
strikes an appropriate balance between effectiveness and annoyance and
meets the need for safety.
As NHTSA explained in the NPRM and PRIA, and explains in the FRIA,
over the years there have been a number of studies of reminder
effectiveness by NHTSA and others. The results of these studies have
been consistent though somewhat fragmentary. In general, longer
warnings are more effective than shorter warnings, and audio-visual
warnings are more effective than visual warnings alone. Overall, these
studies provide evidence that the relative annoyance (e.g., longer
duration, more frequent cycle) of a warning increases the
effectiveness. The studies also suggest that annoyance and
effectiveness are inversely related to acceptance, although not
necessarily in the same way. Therefore, there is the potential to
optimize systems so as to increase effectiveness and also enhance
acceptance. However, NHTSA's research also found that the evidence to
date was not sufficient to clearly identify which specific signal
characteristics were optimal.
The proposal explained that in developing our estimate of the
effectiveness of a front seat belt reminder with an indefinite
duration, we used the results of a study conducted by the Insurance
Institute for Highway Safety (IIHS) by Kidd et al. (2019).\136\ We
explained that the study found that, relative to a short intermittent
reminder, an audio-visual seat belt warning with a 100-second audible
component increased seat belt use by 30 percent, and an audio-visual
seat belt warning with an indefinite audible component increased belt
use by 34 percent. In the NPRM, we explained that there were several
limitations in this study, the main one being that the number of study
participants was small, and, consequently, there was limited
statistical power when comparing the change in rate of belt use between
the different vehicle technology conditions. We noted that the study
further discusses this and other limitations, such as how the
demographics of the
[[Page 423]]
study sample differs from part-time belt users nationwide.
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\136\ ``The effects of persistent audible seat belt reminders
and a speed-limiting interlock on the seat belt use of drivers who
do not always use a seat belt,'' April 2019, David G. Kidd Insurance
Institute for Highway Safety, Jeremiah Singer Westat, Inc.
---------------------------------------------------------------------------
Another limitation in the study is that the confidence intervals
for the reported estimates are large. The 34 percent effectiveness
estimate for the indefinite reminder had a 95 percent confidence
interval of (12.7, 59.9), and the 30 percent effectiveness estimate for
the 100-second reminder had a 95 percent confidence interval of (10.9,
52.4.). Not only are the confidence intervals large, they also
substantially overlap.
We also note that the Kidd study further adjusted these
effectiveness estimates to account for potential circumvention by study
participants (e.g., buckling the seat belt behind the driver's back).
Four of the seventeen study participants assigned to the vehicle with
the 100 second reminder and three of the sixteen participants assigned
to the vehicle with the indefinite reminder circumvented the warning.
Accordingly, ``due to concern that the rate of seat belt use for
participants who circumvented the vehicle technologies could bias the
comparisons being made,'' \137\ the study authors repeated the
analysis, except this time excluding those individuals who circumvented
the warning. With that adjustment, the indefinite reminder increased
seat belt use by 23 percent (95 percent CI [6.5, 42.6]) and the 100
second reminder increased seat belt use by 25 percent (95 percent C I
[8.2, 44.3]).\138\
---------------------------------------------------------------------------
\137\ Id. at pg. 16.
\138\ The study does not report how often these excluded
participants circumvented the warning. Accordingly, this exclusion
could lead the effectiveness estimate to be lower than it actually
was. And to the extent that the rate of circumvention for the
excluded BMW and Subaru participants differed, that could also
affect the relative effectiveness of the indefinite and 100-second
warnings.
---------------------------------------------------------------------------
In addition to these limitations in the Kidd study, the estimation
of the effectiveness in the regulatory analysis has several other
limitations or assumptions. These are discussed in detail in the FRIA.
Thus, while the research is clear that longer durations are generally
more effective than shorter durations, there is no conclusive evidence
regarding what duration will maximize effectiveness (recognizing, of
course, that duration is not the only warning characteristic and that
other attributes, such as duty cycle, also affect effectiveness as well
as annoyance).
Nevertheless, the evidence is such that we are able to easily
reject some of the specific suggestions from commenters for shorter
warning durations. The 4-second and 30-second warnings suggested by
some commenters are well below the typical duration for an audible
warning in current vehicles. Further, a 4- or 30-second reminder is
shorter and less persistent than the intermittent Chevy Cruise reminder
\139\ included in the Kidd study, compared to which both the 100-second
and indefinite audible warnings were significantly more effective. We
are similarly unable to agree with General Motors, which referred to
internal research showing that an audible warning lasting 34 seconds
would be sufficient. (In addition, NHTSA has not seen the underlying
research or data.)
---------------------------------------------------------------------------
\139\ This was an enhanced reminder with three cycles that
occurred at ignition, 105 seconds after ignition, and 360 seconds
after ignition. Each cycle was 20 seconds in duration.
---------------------------------------------------------------------------
The available evidence also does not lead us to conclude with
confidence that, as asserted by Honda and General Motors, a 90-second
continuous warning would be most effective. As we explained earlier,
the Kidd study, while informative, still leaves uncertainty about
whether a 90-second or indefinite warning would be most effective. We
are also unaware of any study, as suggested by Honda, comparing a 90-
second continuous warning to an indefinite 20 percent duty cycle
warning. However, a study of indefinite warnings with 100 percent and
20 percent duty cycles found no difference in their relative
effectiveness, which suggests that a 90-second continuous warning would
not necessarily be more effective than a 20 percent duty cycle
indefinite warning.\140\ Similarly, we are not aware of--and the
commenters did not present--any persuasive evidence that an audible
warning lasting greater than 90 seconds and less than indefinite would
be at least as effective as an indefinite warning.
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\140\ Kidd, D.G. (2012). Response of part-time belt users to
enhanced seat belt reminder systems of different duty cycles and
duration. Transportation Research Part F, 15, 525-534.
---------------------------------------------------------------------------
In light of the available evidence, NHTSA has therefore concluded
that requiring an audible warning that lasts until all front outboard
occupants are belted best and appropriately balances effectiveness and
annoyance, and will help to ensure that as many as possible occupants
take advantage of one of the most safety-enhancing technologies, the
seat belt. As we explained above, there is uncertainty about the most
effective duration and the magnitude of the effectiveness. The
commenters did not provide any persuasive evidence or data that a
shorter audible warning would be at least as effective as an indefinite
warning.
At the same time, there is no uncertainty that seat belts save
lives, and there would appear to be little uncertainty that, regardless
of assumptions and estimates, the monetized net benefits of a long
warning would almost certainly be positive, because almost all subject
vehicles already provide a seat belt warning for the front outboard
seats, and any necessary changes to implement a longer warning (such as
re-programming to optimize the warning characteristics) would likely be
quite low-cost. Moreover, although an indefinite-duration warning would
likely require some re-engineering, audio-visual seat belt warnings are
a longstanding and established technology, so there should be no
concerns about the technical feasibility of such a warning.
Of course, effectiveness and component cost are not the only
considerations in deciding what duration to require. Consumer
acceptance is also crucial, and the Safety Act requires NHTSA to
consider it. NHTSA is cognizant of--and takes seriously--likely
disbenefits from annoyance. Many of the commenters' criticisms relate
to the potential for an indefinite warning being annoying. In the NPRM
the agency acknowledged past studies that found a correlation between
annoyance and warning effectiveness.141 142 Elsewhere in
this preamble we discuss the modifications NHTSA has made to the
proposal in response to the comments in order to address concerns
related to consumer acceptance, such as including a speed threshold for
the indefinite audible warning. However, despite the steps the agency
is taking to make the audible warning acceptable, it is not
unreasonable to expect that there will be some level of annoyance,
particularly from hardcore non-belt users, for an effective reminder.
Similarly, it would be expected that with annoyance would come some
level of distraction. Consequently, we would expect some level of lack
of acceptance from hardcore non-users.\143\ Additionally, we
[[Page 424]]
understand that this lack of acceptance could lead to some level of
misuse or attempts to defeat the system for some in this same group.
The agency has studied such potential misuse in previous research
\144\, and, as noted earlier, some of the Kidd study participants
circumvented both the indefinite and 90 second audible warnings.
---------------------------------------------------------------------------
\141\ N. Lerner et al. (2007). Acceptability and Potential
Effectiveness of Enhanced Seat Belt Reminder System Features.
(Report No. DOT HS 810 848). National Highway Traffic Safety
Administration.
\142\ Kidd, D.G. (2012). Response of part-time belt users to
enhanced seat belt reminder systems of different duty cycles and
duration. Transportation Research Part F, 15, 525-534.
\143\ The Kidd study excluded from participation individuals who
reported never using a seat belt from participating in the study. As
we explain in Section VIII, Overview of Benefits and Costs and the
FRIA, our benefits estimates conservatively assume that an
indefinite audible warning will not cause occupants who ``never''
use a seat belt to begin using a seat belt. This is a change from
the PRIA, which assumed that the indefinite reminder would be
effective for such occupants. We note that the NPRM incorrectly
stated that ``for the purposes of our effectiveness (and benefits)
analysis, we conservatively assume that the increase in belt use
would be due entirely to part-time nonusers'' (pg. 61711, n.231).
\144\ Mazzae, E.N., Baldwin, G.H.S., & Andrella, A.T. (2018,
October). Performance assessment of prototype seat belt misuse
detection system. (Report No. DOT HS 812 593). National Highway
Traffic Safety Administration. NHTSA has chosen not to implement
measures to harden the systems against misuse at this time, for the
reasons expressed in the NPRM. However, the agency will monitor this
situation and act in the future if need be.
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NHTSA, however, believes that the population of occupants who will
not respond to the warning by fastening the belt will be relatively
small in number; as noted earlier, about 5.4 percent of occupants never
or seldom use a seat belt. Moreover, we note that NHTSA's survey data
does suggest that even though ``[s]eat belt reminder systems are likely
to have little effect on hard-core nonusers who choose not to buckle
up'',\145\ some individuals who report never using a belt would likely
be responsive to a reminder. When asked about their reasons for not
using a seat belt, many people who report never using a seat belt give
reasons suggestive of some amenability to a reminder (for example, only
driving a short distance or forgetting), as opposed to reasons that
indicate general opposition to belts (such as e.g., ``don't like being
told what to do'' or ``belts sometimes cause injuries'').\146\ In
addition, many of those who never or rarely used a belt do not
necessarily hold strongly negative beliefs about seat belts or seat
belt use. For example, of drivers who never or rarely used a belt, 43
percent do not report disliking seat belts or finding them annoying;
\147\ about half do not believe that the belt is just as likely to harm
them as help them; \148\ and only 20 percent report that putting on a
seat belt makes them worry.\149\ And, when asked whether they would
want a belt on in a crash, 63 percent of drivers who never or rarely
use a belt strongly or somewhat agreed that they would want to be
wearing a belt in a crash.\150\ This is consistent with NHTSA's other
research, which acknowledges that occupants who sometimes use belts are
the primary target for seat belt reminders, but not necessarily the
only target.\151\ Therefore, while our benefits analysis excludes
occupants who never use a seat belt, we would expect at least some of
these nonusers to begin using a seat belt. Accordingly, overall we
believe that the public will accept the required reminder, and that it
will not negatively impact public acceptance of warnings in general.
---------------------------------------------------------------------------
\145\ Buckling Up: Technologies to Increase Seat Belt Use.
Special Report 278, Committee for the Safety Belt Technology Study,
Transportation Research Board of The National Academies (2003), pg.
40.
\146\ 2016 MVOSS, pg. 71(Fig. 53).
\147\ 2016 MVOSS, pg. 79 (Fig. 55).
\148\ 2016 MVOSS, pg. 89 (Fig. 64).
\149\ 2016 MVOSS, pg. 90 (Fig. 65).
\150\ 2016 MVOSS, pg. 88 (Fig. 63).
\151\ For example, as we stated in the NPRM (pg. 61705), the
2004 Transportation Research Board Report notes that part-time belt
users are the primary (not sole) target group for seat belt
warnings.
---------------------------------------------------------------------------
On the whole, in light of the uncertainty about the duration that
will be most beneficial; the unquestioned benefit and effectiveness of
seat belts; the relatively small proportion of users who will choose
not to use the belt and will either experience annoyance from the
reminder or choose to circumvent it; and recognizing that in MAP-21
Congress removed the statutory limitation on the required duration for
an audible seat belt warning, NHTSA is choosing to require an audible
warning that lasts until the front outboard occupants are belted
(again, subject to additional triggering criteria, such as the 10 km/h
speed threshold).
The other points raised by the commenters also do not persuade us
to require a shorter warning. Commenters opposed to the indefinite
warning also argued that it would be desensitizing. This conclusion
does not seem to be consistent with the IIHS study where the findings
indicate that a long duration warning may have a greater impact on seat
belt use,\152\ and the comments by Honda and GM that warnings lasting
90 or 34 seconds (respectively) may be more effective than an
indefinite warning. As to the comments that a seat belt warning will
cause other warnings to not be recognized, we address this in the
Section VI.C.4. As to the comment by Auto Innovators that an indefinite
warning in the front would be inconsistent with the agency's conclusion
to limit the rear seat warning to 60 seconds because a longer warning
could be distracting, the commenter did not provide the full context of
the rationale for the agency's conclusion. Our conclusion was partially
based on the fact that the rear seat warning system does not require
occupant detection. Because of this, the rear seat belt warnings
(particularly what the NPRM referred to as positive-only or full-status
systems, which provide information on belted, as well as unbelted,
occupants) function more as a source of information for the driver,
rather than as a true ``warning'' for an unbelted occupant. It was for
this reason that we believed that it was not necessary to require a
particularly long-lasting warning for the rear. This logic does not
apply to the front seats, for which occupant detection is either
required or (for a driver's seat) can be assumed. Accordingly, the
audio-visual signal functions more as a warning than as a source of
information, because it is not activated for a belted occupant.
---------------------------------------------------------------------------
\152\ Kidd, D.G., and Singer, J. (2019, April) The effects of
persistent audible seat belt reminders and a speed-limiting
interlock on the seat belt use of drivers who do not always use a
seat belt. Insurance Institute for Highway Safety, Westat, Inc.
---------------------------------------------------------------------------
Audible Warning Activation
The final rule incorporates a two-phased audible warning. The
first-phase audible warning is required to activate whenever the
ignition switch is placed in the ``on'' or ``start'' position (or upon
manual activation of the propulsion system, but prior to the vehicle
being placed in ``possible active driving mode'' as defined by FMVSS
No. 305),\153\ the seat is occupied, and the seat belt is not in use.
The first-phase audible warning must continue for 30 seconds, until the
seat belt that triggered the warning is in use, until the seat is no
longer occupied, or until the second-phase warning activates, whichever
comes first. The second-phase audible warning must activate and remain
active when the vehicle speed is equal to or greater than 10 km/h (6.2
mph), the seat is occupied, and the seat belt is not in use.
---------------------------------------------------------------------------
\153\ This EV-specific language is discussed in Section VI.C.1.
---------------------------------------------------------------------------
The agency believes that this change in the triggering strategy
from that specified in the NPRM will address many of the concerns
expressed by the commenters related to potential user annoyance such as
when the vehicle occupant is in a stationary vehicle, e.g., interacting
with non-driving aspects of the vehicle or waiting for the vehicle's
climate control. This change will also ameliorate the concerns related
to EVs triggering the indefinite warning while being on, but stationary
(Auto Hold applied).
We are rejecting advice from commenters suggesting requiring only a
visual warning upon vehicle start. Such
[[Page 425]]
a requirement would not even be consistent with the 4-8 second audible
warning requirement currently in FMVSS No. 208. The initial 30-second
audible warning remains important for the reasons expressed in the NPRM
for why we want such a warning to initiate at vehicle start. We believe
basing the trigger on the ignition switch is preferable to delaying the
warning until the vehicle is placed in gear because the proposed
requirement would make it more likely that the occupants fasten their
belts before the vehicle is in motion.\154\
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\154\ DOT 2009 Seat Belt Study at pg. 65.
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The selection of 30 seconds is consistent with the ECE R16 start-up
visual warning duration and the rear seat change-of-status audible
warning for this final rule. We believe the 30-second audible warning
will maintain the agency's goal of an effective warning at the start of
a trip, while increasing the level of acceptance from what might be the
case if the start-up warning remained indefinitely active. The initial
30-second audible warning will have the same characteristics as the
rear seat change-of-status audible warning, i.e., the warning may be
continuous or intermittent. If intermittent, inactive periods longer
than 3 seconds will not be counted toward the total duration of the
warning and no gap longer than 10 seconds is allowed. These are also
characteristics required by the ECE R16 audible warning, except for the
10-second gap limit, which is required by Euro NCAP.
The second-phase audible warning is important to encourage belt use
for occupants that would otherwise wait out a finite warning and not
buckle their belt. The 30-second start-up warning alone would have very
little additional safety benefit, given that nearly all new vehicles
already have audible warnings of this length or greater. Additionally,
the agency agrees with commenters that a speed-based approach for the
indefinite audible warning should address pick-up and drop-off
situations that could lead to consumer backlash, particularly for
frequent belt users.
The selected speed threshold (10 km/h (6.2 mph)) is aligned with
the IIHS rating system and Rivian's recommendation. ECE R16 also uses a
10 km/h (6.2 mph) threshold for its definition of when a vehicle is in
normal operation, and 10 km/h (6.2 mph) is within its maximum allowed
speed threshold (25 km/h (15.5 mph)). The selected speed threshold is
meant to address such scenarios as where the vehicle is parked, driving
to a mailbox, on a long driveway, driving in a parking lot/garage, or
dropping off passengers, but is not high enough that vehicles will be
able to drive on roadways and not get a warning. Once the vehicle is
traveling below 10 km/h (6.2 mph), the warning may deactivate. We are
not allowing for any delay in the warning after the speed threshold is
reached as is allowed by the IIHS rating,\155\ as we do not believe
such a delay is necessary to achieve our goal of limiting the
activation of the audible warning for regular belt users and would be
counterproductive (i.e., increase the amount of time at which unbelted
occupants do not get a warning).
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\155\ IIHS allows for a 30-second delay at speeds between 10 and
40 km/h (6.2 and 24.9 mph) and a 2-second delay at speeds at and
above 40 km/h (24.9 mph).
---------------------------------------------------------------------------
The agency is not allowing manufacturers the choice to initiate the
warning based on a combination of speed, timing, or distance traveled,
such as is the case for the second level ECE R16 warning. We believe
that vehicle speed is the most relevant parameter and that 10 km/h (6.2
mph) limit is sufficiently low to achieve the agency's safety goals.
Analysis of agency field data indicates that a 10 km/h (6.2 mph) delta
V frontal crash shows a 28 percent probability of MAIS1 and 1.7 percent
MAIS2 injuries and essentially no risk of higher level injury, whereas
at 20 km/h (12.4 mph) there is a 39 percent probability of MAIS1 and
4.0 percent MAIS2.\156\ Though still low probability, this is a 2.4-
fold increase in the risk of MAIS2.\157\ Although equating vehicle
travel speed to delta V would tend to overestimate occupant injury, the
results are directionally correct, and a higher speed threshold (or
delay in initiating a particular speed threshold) would tend to
increase injury risk.
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\156\ Wang, J.-S. (2022, May). MAIS(05/08) injury probability
curves as functions of delta V (Report No. DOT HS 813 219). National
Highway Traffic Safety Administration.
\157\ At 25 km/h (15.5 mph) there is a 41 percent probability of
MAIS1 and 4.3 percent MAIS2.
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We acknowledge that the data show that MAIS1 and MAIS2 injuries,
which are meaningful safety concerns, occur frequently in collisions
with delta V at 10 km/h, and that this final rule appears to depart
from the NPRM's stated belief that seat belts provide a safety benefit
even at lower speeds, regardless of the direction of motion. We also
grant that in rare cases a vehicle traveling at a speed below 10 km/h
(6.2 mph) may be struck by another vehicle traveling at a higher speed
and that seat belt protection would be beneficial in such cases.
However, we believe that the resulting increase in the warning systems'
overall level of acceptability (which is an important consideration for
both meeting the safety need and practicability), particularly for
those that regularly wear seat belts, will outweigh the negative
effects from non-activation of the warning system below 10 km/h.
The second phase indefinite audible warning will also serve as a
change-of-status warning, except that now that the indefinite audible
warning is speed based, there is no need to relate activation to the
gear selection or door opening status as was proposed. The fact that
the speed threshold is exceeded is a sufficient reason for the audible
warning to be active.
With respect to AVIA's comment about modifying the provision for
resetting the system when a door is opened for the front seats to
address novel seating configurations, NHTSA believes these types of
vehicles, specifically vehicles without a driver's seating position
where all seats in the front and/or rear rows may be accessed via a
common door, are beyond the scope of this rule. The agency did not
develop the finalized seat belt warning requirements with these
specific vehicles in mind. In any case, AVIA's concern about exposure
to the proposed audio-visual change-of-status warning in these vehicles
under the scenario it described in its comment is largely addressed by
the finalized requirements for the front seat for change-of-status
events, which only requires the activation of a visual warning in a
drop-off scenario given the speed trigger criteria for the audible
component.
Visual Warning
The final rule requires that a visual warning activate and remain
active whenever the ignition switch is in the ``on'' or ``start''
position (or the propulsion system is activated), the seat is occupied,
and the seat belt is not in use. The final rule condenses the proposed
``start of trip'' and ``change-of-status'' visual warnings into a
single requirement and changes the proposed activation triggers in a
few ways.
We agreed with Honda's comment that under the proposed rule, if an
occupant unbuckled while the vehicle was in park, no warning would be
required to activate, even if the vehicle were subsequently placed in
gear and commenced moving. We therefore believe that a ``change-of-
status'' visual warning should not be limited to when the vehicle is in
a forward or reverse drive mode. Accordingly, for the visual warning,
we removed the activation triggers that referred to the ignition switch
being placed in the ``on'' or ``start'' position and to the
transmission
[[Page 426]]
gear position. (We have also made analogous changes to the regulatory
text related to EVs. These changes are discussed in Section VI.C.1.)
These changes will ensure that a warning is activated whenever the
vehicle is on and a driver or front outboard passenger is in the seat
and not belted. Because this only applies to the visual warning--and
not the audible warning--we do not believe this will lead to issues
with consumer acceptance, because a visual warning is not nearly as
intrusive as an audible warning. (On the other hand, as we explain in
the preceding section, we have modified the proposed triggers for the
audible warning to limit the scenarios in which it will activate to
address concerns with consumer acceptance.) Concerns with consumer
acceptance are further allayed by the fact that the warning requirement
is tied to seat occupancy, so there will not be nuisance alarms for an
unfastened belt at an unoccupied seat.
The finalized regulatory text also adopts Honda's suggestion that
the proposed change-of-status warning include seat occupancy as one of
the triggering conditions. Because the front seats are either equipped
with occupant detection or (for the driver's seat) occupancy can be
assumed,\158\ there is no reason to require a visual warning for an
unoccupied seat. This also addresses the misuse case Honda identifies.
Including seat occupancy as a trigger also allows us to further
simplify the triggering logic for the visual warning by deleting the
exception to the proposed change-of-status warning for when a front
door on the same side of the vehicle as the seat belt triggering the
warning is open. This language is now unnecessary because seat
occupancy is one of the triggers for the visual warning--in a scenario
where a driver or front outboard passenger unbuckles and disembarks, a
visual warning is not required because the seat is no longer occupied,
and any reference to a door opening is unnecessary.
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\158\ See Section VI.B.5.
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We also implemented Auto Innovators' recommendation to delete the
proposed restriction that the audio-visual warning is permitted to
activate only to comply with the requirements in this rule.
The finalized requirements for the visual warning are also
generally consistent with the broad tenor of the comments on the
proposed audio-visual warning, which, as we discussed earlier, were
primarily concerned with the proposed indefinite audible warning and
the proposed triggers for that warning. For example, we agreed with
Mercedes and NADA that the change-of-status warning should better
harmonize with ECE R16 and now require only a visual warning if the
vehicle is stationary or travelling at low speeds. We did disagree with
the commenters who suggested a shorter visual warning (at or below the
30 seconds required in ECE R16) because, among other things, we believe
both that a longer visual warning will be more effective than a shorter
warning and also that a long visual warning does not pose the same
consumer acceptance concerns as does a long audible warning.
4. Visibility of Visual Warning for Front Outboard Passenger Seat Belt
We proposed requiring that if there is a driver's designated
seating position, the visual warning for the driver's seat belt must be
visible from the driver's seat and the visual warning for the front
outboard passenger seat belt must be visible from both the driver's
seat and the front outboard passenger seat. We did not propose to
specify more detailed criteria for location or visibility of the
telltale. (For discussion of vehicles with no driver's designated
seating position, such as ADS-equipped vehicles without any manual
driving controls, see Section VI.C.7.) We proposed requiring that the
visual warning for the front outboard passenger seat belt be visible to
both the driver and the front outboard passenger because NHTSA's study
on front seat belt warning systems suggests that visual warnings for
front outboard passenger seat belts are more effective when they are
visible to the passenger as well as the driver.\159\ We tentatively
believed it would be practicable for manufacturers to comply with this
requirement; for example, the warning could be located in the center
console display (which might be a salient place to present visual
displays, both because of its location and because it may allow larger
size icons or text).\160\ Some manufacturers already provide a
passenger seat belt warning in close proximity to the passenger air bag
status indicator, which is visible to both the driver and front
passenger.
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\159\ See DOT 2009 Seat Belt Study at pgs. 67-68.
\160\ Id.
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We did not propose more detailed criteria for the location or
visibility of the telltale as, for example, are provided in FMVSS No.
208 S19.2.2 for the passenger air bag telltale. A visual warning for
the driver's seat belt has been required since the early 1970s and we
are not aware of any issues with the visibility of that telltale, so we
tentatively believed more detailed requirements to be unnecessary.
IIHS's ratings system specifies for the front outboard passenger
seat that a visual signal must be displayed in the instrument panel,
overhead panel, or center console, indicating an unfastened belt.
ECE R16 specifies only that the visual warning must be readily
visible and recognizable in the daylight and at nighttime by the driver
and distinguishable from other alerts.\161\ Euro NCAP recommends that
the visual signal must be clearly visible to the driver, without the
need for the head to be moved from the normal driving position (such as
in the instrument panel, head-up display, rear-view mirror, or center
console).\162\
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\161\ Section 8.4.2.1.1.
\162\ Section 3.4.1.1. We note that the NPRM incorrectly
referenced a prior version of the Euro NCAP protocols which
specified visibility to the passenger. NHTSA appreciates Auto
Innovators' comment noting that the referenced material was removed
in v8.0 of the assessment protocol.
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Comments
A number of commenters, such as Auto Innovators, Mercedes, Ford,
Nissan, HATCI, NADA, Toyota, and Honda, commented that the rule should
require only that the front outboard passenger seat visual warning be
visible to the driver. Mercedes noted that the agency did not provide
any insight on how to achieve the passenger visibility requirement.
Ford commented that a visual warning for front row passenger belt use
that is visible to both driver and passenger may be unnecessary, overly
complex to implement, and delay implementation. Auto Innovators and
Mercedes commented that requiring passenger visibility of the visual
reminder would be inconsistent with ECE R16 and Euro NCAP.
Auto Innovators, Nissan, HATCI, Mercedes, Ford, and NADA all
commented that the driver has primary responsibility to notify and
ensure occupants fasten their seat belts and that the occupant in the
front passenger seat will be alerted by the audible warning if the seat
belt is not fastened. Honda noted that the primary mechanism for
encouraging seat belt use is the audible alarm, and that the visual
indicator primarily serves to explain the cause of the alarm. Honda
stated that because the driver can hear the audible alarm and interpret
the visual alarm, the passenger telltale becomes a matter of
convenience.
Honda also commented that the proposed outboard passenger
visibility requirements have questionable merit because the DOT 2009
Seat Belt Study, the research upon which much of the expected benefits
of the requirement
[[Page 427]]
was based, has limitations. Honda noted aspects of the study and the
design of the warnings used in the study, such as unusually large and
aggressive indicators, which may limit the effectiveness conclusions
that can be drawn from the study. Honda commented the study noted that
in actual tests the most effective seat belt warning modality was the
audible chime that repeated at a frequent interval, which suggested
that the placement of the passenger telltale being visible to the
passenger is of questionable efficacy.
Auto Innovators, HATCI, Nissan, Mercedes, Ford, NADA, and Honda all
commented that requiring that a warning also be visible to the front
outboard passenger would require significant interior redesign of
displays. Auto Innovators commented that this requirement would likely
require either all visual warnings be in a central position (outside of
the instrument cluster) so that they are visible to both the driver and
right front passenger, or a second visual warning located in a central
position to solely communicate the status of the passenger seat belt.
Several of the commenters stated that this requirement would
necessitate additional lead time.
Toyota, Auto Innovators, and Honda commented that requiring front
outboard passenger visibility would be unnecessary and inconsistent
with the agency's proposed approach to the rear seat reminder
requirements. They emphasized that the agency did not propose a
requirement that visual warnings/indicators be visible to rear seat
occupants, and that the agency is being inconsistent by proposing a
requirement that the front seat visual reminder must be visible to the
passenger, while the rear seat visual reminder only must be visible to
the driver. These commenters expressed that the visual alert visible to
the driver combined with the required audible alert would be sufficient
to ensure that occupants in both the rear and the front passenger seats
know their belt status.
Auto Innovators and Honda commented that while FMVSS No. 208
specifies requirements for a telltale to indicate the status of the
passenger air bag for those seated in the front outboard passenger
seat, this does not create a precedent, or support the need for, a
similar front outboard passenger belt reminder telltale. Auto
Innovators and Honda argued that with respect to seat belt use, the
passenger can verify, based on a visual or manual check, whether their
seat belt is buckled. This is not the case for air bag systems.
Agency Response
The final rule requires that the front outboard passenger seat belt
visual warning be visible only to the driver, with two exceptions
related to ADS-equipped vehicles. In response to comments, we have
decided not to require that the visual warning for the front outboard
passenger seat belt be visible from the front outboard passenger seat.
Retaining this requirement for the driver is critical for generating a
communication dynamic between the driver and passenger, which is
discussed further in this section and in Section VI.C.3 below.
Manufacturers retain the flexibility to incorporate a visual signal
that is visible to both the driver and front outboard passenger (or an
additional signal visible to the passenger), and many already do. The
final rule harmonizes with ECE R16 and Euro NCAP. It also matches the
requirements for the visibility of alerts for the front passenger and
rear seat belt reminders.
Although there is limited information available on the safety
benefits and compliance costs of a passenger visibility requirement,
what information we have suggests that both would likely be low, at
least in the context of this final rule. In this instance we feel that
the relatively minimal benefits do not justify the costs that could be
realized.
With respect to benefits, because this final rule requires an
audible alert, it (along with the visual warning provided to the
driver) can serve the role provided by a visual warning to the
passenger. The primary study we used to support this proposal does
suggest that visual alerts may be more effective when the passenger
sees them. It also notes that the visual alert may present an
opportunity for communication between driver and passenger to prompt
passenger belt usage.\163\ However, given that this rule requires an
audible warning which can initiate this communication, the visual alert
for the passenger would likely serve a supporting role, limiting its
added benefit.\164\
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\163\ DOT 2009 Seat Belt Study at pg. 66.
\164\ We also note that this research noted the efficacy of
audible alerts, but suggested not using an alert audible to drivers
for the passenger's belt due to consumer acceptance concerns.
However, as discussed in the NPRM and elsewhere in this final rule,
research shows that consumers are now far more accepting of audible
alerts. Therefore, the audible alert required by this final rule may
serve to more effectively perform the communication role that this
research suggested the visual alert to the passenger did. See DOT
2009 Seat Belt Study at pgs. 67-68.
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It is also worth noting that under the requirements of this final
rule there are only rare scenarios in which a visual alert is the only
alert required to be active. We are requiring an indefinite audible
alert if the vehicle is traveling at or over 10 km/h (6.2 mph) and a 30
second minimum start-of-trip audible warning if there is an unbelted
front passenger. Therefore, the only situation in which the visual
alert is the only active warning is when the vehicle is traveling under
10 km/h (6.2 mph) (or stopped) and the start-of-trip warning has
elapsed. These situations are limited, and field data shows only small
risks of injuries with severity above MAIS1 and almost no risk of
injuries with severity above MAIS2 in frontal crashes at these speeds.
Therefore, while research suggests the proposed visibility requirement
might generate some safety benefits, given the structure of this final
rule those additional benefits are hard to determine and may only be
minor.\165\
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\165\ Other research referenced in the NPRM that suggested a
passenger visibility requirement might increase effectiveness was
preliminary on this point and precluded firm conclusions. For
example, some research noted that it is not evident to what extent
improved effectiveness is due to direct message effects on the
passenger and to what extent it may be due to more complex social
dynamics between the driver and the passenger. We also cited studies
that suggest that center console display locations might be more
effective than dashboard display locations but were not conclusive
due to other differentiating factors in the visual designs, such as
character size, display size, and color, which may be covaried. See
N. Lerner et al. (2007). Acceptability and Potential Effectiveness
of Enhanced Seat Belt Reminder System Features. (Report No. DOT HS
810 848). National Highway Traffic Safety Administration; DOT 2009
Seat Belt Study.
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Regarding costs, we disagree with commenters about the size and
scope of the costs associated with incorporating a signal visible to
the passenger. However, we understand that, depending on how
manufacturers decided to implement the proposed requirement, there
could be more than de minimis costs for certain vehicles and these
costs may outweigh the benefits of this requirement.\166\ Given this
potential imbalance and our belief that most if not all of the desired
benefits will be achieved by the indefinite audible warning, we are
only finalizing that the front passenger's visual seat belt warning be
visible to the driver.
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\166\ Given that many manufacturers currently provide visual
alerts in the center console or in proximity to the passenger
advanced air bag signal, we maintain our confidence that in many
cases the cost would be limited and encourage manufacturers to
voluntarily provide visual warnings to the passenger.
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This approach is consistent with the approach we took for the rear
seat belt warning. In the NPRM, we did not propose that the rear seat
visual warning be visible to the rear passenger because
[[Page 428]]
we did not believe that the benefits would outweigh the costs (viewed
qualitatively). On the other hand, the NPRM did propose this for the
front outboard passenger seat belt warning, because in that case we did
expect the benefits to be greater than the costs. We now agree with the
commenters, however, that because of the relatively low benefits;
potentially non-de minimis costs for at least some vehicles; and the
interplay between the visual and audible signals, that it is
appropriate not to require that the visual warning for the front
outboard passenger be visible to that passenger.
We also wish to clarify the purpose of our reference, in the NPRM,
to the advanced air bag visual signal because Honda's and Auto
Innovators' comments suggest it may have caused some confusion. In the
context of visibility, we referenced the advanced air bag telltale for
the passenger only to indicate that it provides a location some
manufacturers already use for a visual signal that is visible to the
passenger. We did not intend to make any statements about the purpose
of these signals within the structure of the FMVSS, their relative
safety benefits, or the meanings they convey.
Finally, we believe it is important to address two potential future
situations where only requiring the visual warning to be visible to the
driver would not be sufficient. The first is for dual-mode ADS-equipped
vehicles that still have a driver's seat and driving controls.\167\ For
such vehicles the driver's seat could remain unoccupied throughout the
vehicle's operation. In this situation, limiting the visibility of the
front seat warnings to the driver's seat would result in the passenger
not seeing the warning. The second is for ADS-equipped vehicles without
a driver's designated seating position. For the former, the final rule
requires that the visual warning for the front outboard passenger seat
belt must be visible from the front outboard passenger seat, and for
the latter the final rule requires that the visual warning for each
outboard designated seating position be visible from each outboard
passenger seating position.
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\167\ An ADS-Equipped Dual-Mode Vehicle is defined as ``[a] type
of ADS-equipped vehicle designed for both driverless operation and
operation by a conventional driver for complete trips.'' SAE
J3016_201806 Taxonomy and Definitions for Terms Related to Driving
Automation Systems for On-Road Motor Vehicles.
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5. Front Seat Occupant Detection and Seat Occupancy Criteria
In the NPRM, we proposed a single compliance option that requires a
start-of-trip audio-visual warning that lasts until the seat belt at
any occupied front outboard seat is fastened. We proposed that the
warning system consider the front outboard passenger seating position
``occupied'' when an occupant or dummy that weighs at least 46.7 kg
(103 lb) and is at least 139.7 cm (55 in) tall is seated in the seat,
which matches the specification in FMVSS No. 208 for a person who is
used as an alternative for the 5th percentile adult female test dummy
for compliance testing of advanced air bag systems using static
suppression. The NPRM also proposed giving the manufacturers the option
to use a human being instead of using test dummies for testing
purposes. Requiring occupant detection for front outboard passenger
seating is consistent with Euro NCAP and IIHS ratings protocols, and
the specification is consistent with Euro NCAP and the ECE R16 test
procedures. IIHS does not specify any occupancy criteria for either
front outboard seating positions.
However, the NPRM was unclear about the occupancy requirements
pertaining to the driver's designated seating position. The proposal
included occupancy as a condition to trigger the warning for the
driver's seat. The proposed test procedures also specified they applied
to ``front designated seating positions.'' Thus, the test procedures
would have applied to both front outboard seating positions and
therefore may have required NHTSA to place a dummy or a human being in
the driver's seat to establish occupancy for the test. However, we did
not propose to define ``occupied'' for the driver's seat.\168\
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\168\ Occupant detection systems are currently used for front
outboard passenger seating positions to comply with the advanced air
bag requirements in FMVSS No. 208. However, this is not the case for
driver's designated seating positions, which do not have the same
considerations.
---------------------------------------------------------------------------
Euro NCAP and IIHS allow occupancy for the driver's seat to be
assumed. ECE R16 does not require the driver's seat to be occupied in
its test procedures for the start-of-trip warning.
For the change-of-status warning for the front outboard passenger
seat, NHTSA did not propose that the seat must be occupied when the
buckle is unfastened to trigger the alarm. On the other hand, IIHS
protocol requires occupancy to trigger the change-of-status warning and
ECE R16 allows the warning to be discontinued if the seat which
triggered the warning is no longer occupied. This is also true of
IIHS's and ECE R16's specification for the driver's seat.
Comments
IEE, Honda, and Consumer Reports expressed support for requiring
occupant detection for the front outboard passenger seat and for using
occupancy as an element of the trigger for the front outboard passenger
seat warning. Consumer Reports commented that it agrees with NHTSA's
decision to align with Euro NCAP and require an occupant detection
system for the front outboard passenger seat. Consumer Reports further
explained that occupant detection is already widely deployed in these
seats, either as part of an advanced air bag system or as part of a
voluntary seat belt warning system, reinforcing the feasibility of
equipping vehicles with occupant detection technology. IEE commented
that it supports NHTSA's proposal to use the 5th percentile female as
occupant detection criteria for the front outboard passenger seat
because it aligns with the requirements for the sensors installed in
the front passenger seats of vehicles complying with the advanced air
bag requirements of FMVSS No. 208 and the same sensors are widely used
for the voluntary front passenger seat belt warning systems.
Honda commented requesting clarification on occupant detection for
the driver's seat. Honda explained that the NPRM proposed that the
start-of-trip warning for front outboard seats must activate ``if the
seat is occupied,'' among other conditions. It commented that while
this language is an appropriate condition for the front outboard
passenger seat, it is unnecessary for the driver seat. Honda further
commented that FMVSS No. 208 does not contemplate an occupant detection
system because a driver is assumed to be present in a conventional
vehicle. Honda recommended that this language be revised so that
occupant detection requirements are not unintentionally prescribed for
the driver's seat.
Honda commented that if a speed threshold is not adopted for the
change-of-status warning and the proposed transmission trigger is
retained, NHTSA should also use occupant detection as a trigger.\169\
Honda believes this recommendation would resolve a
[[Page 429]]
misuse case in which someone buckles an empty seat and then unbuckles
it. Honda expressed concern that under the proposal this type of
scenario would require an unending alarm until the seat is re-buckled
or the door is opened.
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\169\ Specifically, Honda recommended the change-of-status
warning should be revised to read as follows: ``An audio-visual
warning must activate when the ignition switch is in the `on' or
`start' position, the vehicle is in forward or reverse drive mode,
the seat is occupied (other than the driver's seat for vehicles with
a designated driver seating position), and the status of the seat
belt changes from in use to not in use, unless a front door on the
same side of the vehicle as the seat belt triggering the warning is
open, in which case a warning is not required and the system may
consider this as a new trip with respect to that seat belt and reset
the warning system.''
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Agency Response
NHTSA appreciates IEE's, Honda's, and Consumer Reports' support for
requiring occupant detection for the front outboard passenger seat and
for using occupant detection as an element of the trigger for the front
outboard passenger seat warning. In addition, NHTSA received no
comments in opposition to requiring vehicles to have occupant detection
capability for front outboard passenger seats or for including front
outboard passenger seat occupancy as one of the trigger conditions for
the start-of-trip front outboard passenger seat belt warning. Likewise,
NHTSA received no comments in opposition to specifying that the warning
system consider a front outboard passenger seating position
``occupied'' when an occupant or dummy that weighs at least 46.7 kg
(103 lb) and is at least 139.7 cm (55 in) tall is seated in the seat.
We are finalizing these provisions proposed in the NPRM with some
revisions to the final regulatory text for clarity.
With respect to a driver's seat, we have modified the proposal to
clarify that the final rule does not require occupant detection for the
driver's seat. The final rule does specify seat occupancy as one of the
criteria for activation of all of the required front seat belt warnings
(the visual warning and first- and second-phase audible warnings).
However, the final rule also provides manufacturers with three
compliance options for certifying that a driver's seat belt warning
complies with these requirements. First, a manufacturer may certify
that the system meets the requirements when the 5th percentile female
test dummy described in part 572 \170\ of this chapter, as well as any
larger dummy described in part 572, is seated in the seat. Second, a
manufacturer may certify that the system meets the requirements when
any human occupant that weighs 46.7 kg (103 lb) or more and is 139.7 cm
(55 inches) tall or taller is seated in the seat.\171\ Third, a
manufacturer may certify that the system meets the requirements when,
instead of seating a dummy or human, the seat is considered occupied
when the ignition switch is in the ``on'' or ``start'' position (or the
propulsion system is activated). Similar to the front outboard
passenger seat, the first two options would necessitate occupant
detection technology and is technology-neutral with respect to the type
of occupant detection technology used. The third option is consistent
with our understanding of how these systems currently work as well as
the approaches taken by Euro NCAP and ECE R16, and essentially allows
the vehicle to infer that the driver's seat is occupied based on the
fact that the vehicle has been turned on.\172\
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\170\ 49 CFR part 572, subpart O.
\171\ These are the bottom of the ranges specified in FMVSS 208
S29.1(f) for the weight and weight of a human female who may be used
in certain of the advanced air bag testing in place of the 5th
percentile female dummy.
\172\ To be clear, although a vehicle might be placed in these
conditions without an occupant in the driver's seat, this is not a
typical or likely scenario in the field because it is the driver
that initiates these conditions (other than for vehicles without a
driver's designated seating position).
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We are finalizing the rule this way for three reasons. First,
requiring that the system activates only when the seating positions are
occupied reduces false activations, which is important both for
effectiveness and consumer acceptance. Although this is a larger
concern for long or indefinite reminders, it is also relevant for the
start-of-trip 30-second audible warning.
Second, requiring occupancy for the driver's seat aligns the
activation criteria for the front outboard passenger and driver's
seating positions. Although Honda suggested that regulatory language is
not necessary because driver's seat occupancy can be inferred,
including it avoids confusion about when the warning needs to or can
activate that could come from specifying different activation criteria.
Third, the first and second compliance options provide
manufacturers the flexibility to optimize systems for vehicles with a
driver's designated seating position, but which may be ``on'' without a
driver in the vehicle, such as dual-mode vehicles equipped with ADS but
which still have a driver's seat and driving controls, as well as
vehicles which use remote start. Because dual-mode vehicles could
operate without an occupant in the driver's seat, we do not believe
that inferring or assuming occupancy (which Euro NCAP and ECE R16 do)
fully accounts for these vehicles. Without the option to use occupant
detection, these vehicles could be required to initiate the driver's
seat start-of-trip audible warning when the ignition switch is placed
in the ``on'' position (or for an EV, when the propulsion system is
activated. Such scenarios would therefore result in false positives. By
allowing manufacturers to select the occupancy method, our approach is
similar in application to the inference approach taken by Euro NCAP and
ECE R16 for conventional vehicles, while being forward-looking for
vehicles with ADS.
To clarify, although adding an activation condition that the seat
is occupied is a change to the current driver's seat belt warning
requirements in FMVSS No. 208, we do not intend it to increase the
stringency of the existing requirement for the driver's seat. The
activation criteria for the current driver's seat belt warning do not
include seat occupancy.\173\ Although the final rule introduces an
occupancy criterion, it does not require occupant detection technology
for the driver's seat. Indeed, we are not defining occupancy for the
driver's seat as we have for the front outboard passenger seat, and the
test procedure for the third compliance option does not require placing
a test dummy (or human) in the driver's seat. Instead, under this final
rule, manufacturers will have the discretion to choose the method by
which the seat belt warning system determines whether the driver's seat
is occupied in the context of seat belt warning activation. The third
option enables systems that do not use occupant detection to certify to
occupancy, while the first and second options enable manufacturers, if
they so choose, to certify using a test dummy or a person
(respectively), which may enable them to optimize a system for vehicles
which may not have a person in the driver's seat at start-up.
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\173\ The activation criteria are (1) the vehicle's ignition
switch is moved to the ``on'' position or to the ``start'' position;
and (2) the driver's lap belt is not in use, as determined either by
the belt latch mechanism not being fastened, or by the belt not
being extended at least 4 inches from its stowed position.
---------------------------------------------------------------------------
Finally, in response to a comment from Honda and to incorporate
considerations for certain vehicles with ADS, the finalized regulatory
text implements Honda's suggestion that the proposed change-of-status
warning have occupancy as one of the triggering conditions. Because in
the final rule, the visual warning and the second-phase audible warning
function as a change-of-status warning, the regulatory text for these
warnings includes seat occupancy as one of the triggering conditions.
C. Issues Common to the Front and Rear Seat Belt Warning Requirements
1. Modification of Start-of-Trip Warning Trigger Related Ignition
Switch Position To Accommodate EVs
As noted earlier, the NPRM proposed that the activation of both the
front and rear seat belt warnings be triggered
[[Page 430]]
when, among other things, ``the ignition switch is placed in the `on'
or `start' position.'' We also stated that this same condition appears
in the existing driver seat belt warning requirements and is similar to
ECE R16 and Euro NCAP.
ECE R16 specifies that the first-level visual warning activates
``when the safety-belt of any of the seats is not fastened and the
ignition switch or master control switch is activated.'' \174\ In the
NPRM we explained that we were not proposing to follow ECE R16 and
refer to a ``master control switch'' because we did not believe it
necessary to introduce this new term into FMVSS No. 208. The second-
level warning and the change-of-status warning have different triggers
that are all based on the vehicle being in motion.
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\174\ Section 8.4.2.3.1.
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Euro NCAP similarly specifies that the visual signal activate
``when the ignition switch is engaged (engine running or not)'' and the
seatbelt is not fastened.'' \175\ Like ECE R16, the audible and change-
of-status warnings have different triggers, mostly related to the
vehicle being in motion.
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\175\ Section 3.4.2.1 (front); section 3.4.3.1.1 (rear).
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The IIHS protocol similarly links the start-of-trip visual signal
to the vehicle engine being ``turned on (i.e., powered and capable of
propulsion).''
Comments
Tesla requested that NHTSA broaden the definition of ``ignition
switch'' to cover, for example, EVs which do not have one. As an
example, Tesla noted that the ``ignition switch'' definition could be
expanded to the moment when power is delivered to wheels to initiate
vehicle motion. Tesla also requested clarity on the definition of
``vehicle start-up.'' Tesla noted that this clarification is especially
important for EVs.
Honda had similar concerns, noting that electrified vehicles may
differ from traditional internal combustion vehicles in that they may
not have a distinct moment when the ignition switch is turned ``on'' or
``started.'' Instead, Honda explained that these vehicles typically use
automatic ``wake'' and ``sleep'' modes, which are activated based on
various sensing and detection algorithms. While Honda preferred that
NHTSA reconsider using the ignition switch as a trigger, it requested
clarification on the start-of-trip warning if it is retained.
Agency Response
We agree with Tesla and Honda that it would be helpful to provide
clarity regarding warning activation for vehicles that do not have a
traditional ignition switch or button with ``on'' and ``start''
positions or conditions, which could be the case for EVs. Therefore, we
are adding regulatory text to address these vehicles.
The start-of-trip warnings (front seat belt visual and first-phase
audible warnings and rear seat belt warning) are required to activate
when (among other things) the ignition switch is ``placed in'' the
``on'' or ``start'' position or upon manual activation of the
propulsion system, but before the vehicle is placed in ``possible
active driving mode'' as defined by FMVSS No. 305.\176\ In developing
this language, our goal was to specify a time in the start-up process
to begin the start-of-trip warning for EVs that is roughly the same as
the time we specified for vehicles with a conventional ignition switch
such that the safety benefits for EVs would be the same as for
ignition-equipped vehicles. For an ignition-equipped vehicle, while in
the ``on'' position the vehicle electrical systems have been powered.
While in the ``start'' position, the engine has been started and in
this state a conventional vehicle is ready to be placed in a drive
mode. An additional consideration is that, for an ignition-equipped
vehicle certified to the option that the system determines the driver's
seat is occupied through movement of the ignition switch to both the
``on'' or ``start'' position, the driver is presumed to be in the
vehicle to initiate the action. However, what actions by the driver
initiate these modes, and whether a vehicle even has an analogous state
to ``on,'' varies widely across EV models. For instance, some EVs, upon
the door being opened, may activate some systems without providing
electrical power to the motors, and may not be ready to be moved into a
drive mode until another action is taken (such as depressing the brake
pedal) which would typically entail the driver being seated. Others,
however, may provide power to the motors upon the door being opened.
Therefore, the agency attempted to incorporate language that
approximates the following moment in a start-up sequence for an EV: an
occupied outboard seat, ready to drive, but not yet in a drive mode.
(This condition also closely approximates when the ignition of a
conventional vehicle, certified to the option which uses the ignition
switch ``on'' or ``start'' to indicate occupancy, is moved to the
``start'' position). These requirements should equalize the safety
benefits of the start-of-trip warning across vehicles with and without
ignition switches.
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\176\ More specifically, the ``placed in'' language is used to
specify the rear seat belt start-of-trip warning and the front seat
belt first-phase audible warning but not the front seat belt visual
warning. The front seat belt visual warning is required to
``activate and remain active whenever the ignition switch is in the
``on'' or ``start'' position (or the propulsion system is
activated), the seat is occupied, and the seat belt is not in use''
(emphasis added). Because this visual warning is also serving as a
change-of-status warning, this text refers to the ignition switch
being ``in'' the on or start position, not being ``placed in'' on or
start. However, in order for the ignition switch to be ``in'' the on
or start position, it must first be ``placed in'' that position.
Accordingly, this language necessarily includes the start of the
trip. Similar reasoning applies to the EV-specific language for the
front seat belt visual warning.
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To accomplish this objective, we are adding language from FMVSS No.
305; ``Electric-powered vehicles: electrolyte spillage and electrical
shock protection.'' That standard defines ``possible active driving
mode'' as ``the vehicle mode when application of pressure to the
accelerator pedal (or activation of an equivalent control) or release
of the brake system causes the electric power train to move the
vehicle.'' \177\ As such, the mode is analogous to the vehicle being
placed in a drive gear. Additionally, FMVSS No. 305, S5.4.6.1 Indicator
of possible active driving mode, states that ``[a]t least a momentary
indication shall be given to the driver each time the vehicle is first
placed in possible active driving mode after manual activation of the
propulsion system.'' This language implies that ``manual activation of
the propulsion system'' precedes the ``possible active driving mode.''
In the final rule that added this language to FMVSS No. 305, we
explained that the phrase ``when the vehicle is first placed in
possible active driving mode after manual activation of the propulsion
system'' was meant to indicate ``start up.'' \178\ Thus, we believe
that the appropriate time in the start-up sequence of an EV (which is
roughly analogous to the movement of the ignition of a conventional
vehicle to the ``start'' position) is upon manual activation of the
propulsion system, but prior to the vehicle being placed in ``possible
active driving mode'' as defined by FMVSS No. 305. We understand that
the process of driving system activation could vary from vehicle to
vehicle but believe that the criteria in the final rule encompass all
or most EV start-up sequences.\179\
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\177\ NHTSA recently proposed to establish FMVSS No. 305a to
replace FMVSS No. 305. The proposed FMVSS No. 305a refers to this
state as ``active driving possible mode.'' However, the definition
is the same. The terminology is originally from Global Technical
Regulation No. 13.
\178\ 82 FR 44945, 44956.
\179\ We also anticipate that if a vehicle activates the
propulsion system before the driver is inside the vehicle, the
warning will be delayed until the driver has entered the vehicle to
comply with the occupancy requirement, even if such a vehicle is
certified to the first option.
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[[Page 431]]
2. Belt Use Criteria
The current driver's belt warning requirements specify that a belt
is ``not in use'' when, at the option of the manufacturer, either the
seat belt latch mechanism is not fastened or the belt is not extended
at least 10.16 centimeters (cm) (4 inches (in)) from its stowed
position.\180\
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\180\ S7.3(c). These are the definitions for manual belts. For
automatic belts, see supra n.18.
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We proposed amending these current criteria by specifying criteria
related only to the seat belt latch mechanism. Specifically, we
proposed that a manual seat belt would be considered ``not in use''
when the seat belt latch mechanism is not fastened, and ``in use'' when
the seat belt latch mechanism is fastened. We proposed eliminating the
spool-out sensor requirements because we tentatively believed that
accommodating the use of a spool-out sensor would not allow for an
objective or reliable criterion for the proposed change-of-status
warning. For instance, there may be instances where the webbing may not
readily spool back in when the seat belt is unbuckled (e.g., due to the
use of shoulder belt routing features or the use of a belt positioning
booster seat), and thus would not reliably trigger the change-of-status
warning.
The proposal differed from ECE R16,\181\ which gives manufacturers
the option of using either a belt latch or spool-out sensor.\182\ Euro
NCAP does not specify webbing spool-out criteria, and only refers to
the status of the belt buckle. The IIHS protocol does not specify such
criteria.
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\181\ Section 2.46.
\182\ Section 2.46.
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Comments
We received one comment from Auto Innovators, which generally
agreed with the agency's proposal to enable compliance with the
regulation through the use of seat belt latch sensors. Auto Innovators
indicated that this proposal is consistent with ECE R16 and avoids
introducing unnecessary complexity in redesigning rear belt reminder
systems for the U.S. market. However, Auto Innovators requested that
NHTSA update the definitions for S7.5 to ensure the regulation supports
additional compliance options for classifying seat belt use, including
systems that rely on camera-based sensors (or other advanced sensor
technology). Auto Innovators commented that, currently, these options
would not be permitted unless the belt use reminder system also
included a belt latch mechanism.
Agency Response
In the NPRM we stated that the current FMVSS No. 208 belt use
criteria for the driver's seat belt warning requirements allow for the
use of a belt latch or spool-out sensor, and that we were proposing to
amend the belt use criteria to rely solely on the use of a belt latch
sensor, and not provide requirements that would accommodate the use of
a spool-out sensor. These statements were imprecise. The intent of the
NPRM was not to restrict the types of technology manufacturers may use
to determine whether or not an occupant is belted. The proposal was
intended to identify objective criteria that NHTSA would use to
determine whether or not a belt is in use. A manufacturer may use
whatever technology it chooses to detect whether a belt is in use or
not. However, regardless of the technology a manufacturer uses--whether
it is a latch sensor or a camera--NHTSA, for the purposes of its
compliance test, will consider a belt to be ``not in use'' when the
belt latch is not fastened. Suppose, for example, that NHTSA tests a
seating position equipped with a spool-out sensor for compliance with
the change-of-status warning requirements. Suppose further that, in the
test, a fastened belt is unfastened, but the spool-out sensor
malfunctions so that the change-of-status warning does not activate.
This would be considered an apparent test failure because the warning
system did not activate when the status of the belt changed from in use
to not in use (i.e., the belt latch became unfastened).
3. Visual Warning Characteristics
NHTSA proposed different requirements for the rear and front seat
belt visual warnings.
Rear Seat Belt Visual Warning
We proposed that the visual warning be continuous or flashing and
consist of icons or text and indicate how many or which rear seat belts
are in use or not in use depending on the type of warning system. If
icons are used to indicate how many or which rear belts are in use, we
proposed that the icon(s) must be green; if icons are used to indicate
to the driver how many or which belts are not in use, we proposed that
the icon(s) be red. If text is used to indicate to the driver how many
or which rear seat belts are in use or not in use, we proposed that the
text contain the words ``rear belt(s) in use'' or ``rear belt(s) not in
use.'' We also proposed to amend table 2 in FMVSS No. 101, ``Controls
and displays,'' to clarify that the ``Seat Belt Unfastened Telltale''
depicted there does not apply to the rear seat belt reminder and to
amend table 1 by adding in a row for the proposed rear seat belt
warning.
The requirement that the visual warning be continuous or flashing
mirrors the current driver's seat belt visual warning requirement and
is also consistent with ECE R16. However, we proposed to depart from
the current driver's warning and from ECE R16 and standardize the color
of the icons and text for the warnings to increase the likelihood that
consumers would notice, recognize, and respond to the warnings. We
believed that standardized colors and text will facilitate the
interpretation of the signal. We departed from the current driver's
warning requirements and followed ECE R16 by not requiring specific
icons because we believe the choice of icons would largely depend on
whether the system displayed the number of seat belts in use or which
seat belts are in use.
Another difference between the proposal and ECE R16 was that ECE
R16 requires that the visual warning ``indicate at least all rear
seating positions.'' We understood this requirement to mean that the
visual warning must depict all the rear seating positions. To give
manufacturers design flexibility, we did not propose to require that
the warning depict all rear seating positions. Instead, the proposed
requirements would allow the visual warning to consist of text or icons
indicating how many or which rear seats are fastened or unfastened. For
example, the warning text might consist of ``Middle and Right rear seat
belts fastened.'' Another visual warning option would be the seat belt
icon with an adjacent numeral indicating the number of rear seat belts
fastened. Accordingly, the proposal would allow, but not require, use
of a pictogram.
Front Seat Belt Visual Warning
The current requirements for the driver telltale differ from those
we proposed for the rear seat belts. As noted earlier in this document,
some vehicles already equipped with a rear seat belt warning system in
addition to a front seat belt warning system combine the two (such as
with a pictogram depicting all seating positions). These vehicles also
must continue to meet the current requirements for the driver seat belt
telltale. These require that the warning be continuous or intermittent
(flashing) and display either the identifying symbol or the words
(``Fasten Belts'' or ``Fasten Seat belts'') specified in table 2 of
FMVSS No. 101. Thus, vehicles that
[[Page 432]]
currently have a rear seat belt warning system using a pictogram also
provide a separate, FMVSS No. 101-compliant telltale for the driver's
seat belt warning.
We proposed generally retaining, for both front outboard seats, the
current visual warning requirement for the symbols or text specified in
FMVSS No. 101 because these visual warnings have been in place for
decades and we believe that consumers are accustomed to them. Removing
the requirement may have unintended negative effects if drivers and
front passengers are not accustomed to new visual warnings or do not
find the new visual warnings as effective. This means that if a
manufacturer chose to use a pictogram format to comply with the new
rear seat belt warning requirements, it could--as many manufacturers
are already doing--include the front seat belts in this pictogram, but
it would also have to provide the telltale specified in FMVSS No. 101,
table 2. As we explained earlier, we proposed that the telltale for the
front outboard passenger seat would also have to be visible to that
passenger. We also proposed to require that for telltales associated
with multiple front outboard seats, the seat with which each telltale
is associated must be clearly recognizable to the driver and front
outboard passenger.
Comments
Regarding the rear seat belt warning telltale, several commenters
suggested that NHTSA should require visual warnings that indicated all
rear seating positions. Consumer Reports encouraged NHTSA to align with
ECE R16 by requiring that visual warnings indicate all rear seating
positions. It argued that although a seating map may require a somewhat
more sophisticated display, it is preferable because it offers the
driver complete information while facing forward. Auto Innovators and
HATCI commented that contextual displays or pictograms are generally
feasible and useful. Auto Innovators also added that several automakers
have already implemented seat belt warning systems that use a
contextual display diagram to provide the driver with information on
the status of passenger belt use.
Some commenters such as HATCI and NADA also explicitly requested
flexibility in telltale design. Rivian requested flexibility in
choosing icons for the front and rear seat belt reminder warnings and
that NHTSA not require the FMVSS No. 101 icon for the front seat belt
reminder warning icon. HATCI supported providing manufacturers
flexibility in the rear seat telltale and commented that the use of a
pictogram for the rear seat belt warning will allow for more
flexibility for different vehicles and vehicle sizes. Consumer Reports
also commented that, within a seating map, easily recognizable icons
are preferable to text, as icons enable a driver to assess seating
usage at a quick glance, without having to read. Consumer Reports also
argued that easily recognizable icons are also useful for drivers for
whom English is not a first language.
NSC commented that seat belt warning systems have different
operational parameters, generic names, and limitations across
manufacturers and sometimes even across the same manufacturer's varying
models. It urged NHTSA to consider standardizing generic nomenclature
as well as standardizing warning and icon symbols to reduce driver
confusion.
Mercedes commented that, based on the requirements in the proposal,
there would be technical challenges with providing the driver seat belt
status information within the instrument cluster for seating
configurations that can hold up to 13 rear passengers.
Auto Innovators commented that in addition to issues related to the
symbol, standardizing the text to say ``Rear belt(s) in use'' or ``rear
belt(s) not in use'' may be difficult to package on the instrument
cluster. Auto Innovators requested that the agency permit the use of
either the word ``Rear'' or a corresponding number next to the seat
belt icon referencing which seating position is unbuckled as an
acceptable alternative. It noted that this request is similar to the
number 2 notation used next to the air bag symbol for specifying the
icon is relevant to the passenger-side air bag.
Auto Innovators and Rivian supported harmonizing the telltale
symbol with ECE R16. However, Auto Innovators, Mercedes, Honda, NADA,
and HATCI requested that the agency also permit the use of a neutral
color (e.g., gray) that could be used to display either an unoccupied
seat or, for positive only systems, a seat that remained in the
unbuckled condition. For negative only and full-status systems, the
symbol would be required to be red to indicate occupancy in an unbelted
condition. Auto Innovators commented that this approach is being widely
adopted in the U.S. and other markets and is understood by consumers.
Accordingly, Auto Innovators requested aligning the color requirements
with ECE R16. Mercedes expressed concern that red icons should not be
used if the buckle has not changed status because there is no critical
information to be shared with the driver, and red could provide a false
alarm and lead to desensitization if it is always on. Hyundai also
noted that it is not aware of consumer complaints or requests to
deactivate existing visual seat belt displays.
Auto Innovators and Rivian argued that, given the prevalence of
red-green color vision deficiency among the U.S. population, the
requirement should not limit the ability of manufacturers to implement
approaches that may be more easily understood or recognized by
consumers. Auto Innovators indicated that the rule should include
allowances for providing a visual diagram of all seating positions
whereby belt use can either be communicated through the presence or
absence of the belted symbol or through the use of a bi- or tri-color
scheme consisting of green and red symbols to indicate belt status, and
either gray or white symbols to denote either unoccupied seats (for
systems with occupant detection) or unbelted seats (for systems without
occupant detection) at the manufacturer's discretion.
Rivian and GM also noted that permitting the use of other icons,
such as a checkmark to indicate belts in-use and a ``x'' to indicate
belts not-in use for both front and rear occupants seat belt status,
could help mitigate the challenges with red and green coloration if
manufacturers were permitted flexibility in the use of different icons
for both the front and rear locations. Rivian further commented that
the agency proposed that the ``Seat Belt Unfastened Telltale''
requirement, depicted in table 2 in FMVSS 101, Controls and displays,
does not apply to the rear seat belt reminder. Rivian stated that its
interpretation of the proposal is that manufacturers may use other
icons such as a checkmark to indicate belts in-use and a ``x'' to
indicate belts not in use. Rivian recommended that for consistency and
occupant recognition, NHTSA allow this design flexibility for the front
and rear belt reminders. It stated that this commonality is
particularly important for pictogram designs driven by other protocols,
such as IIHS, and would help address the color issue.
GM also indicated that glanceability can be significantly improved
through redundancy, which involves combining both color and forms as
cues. It cited several studies in support of this assertion. GM argued
that the symbols, along with the colors of green representing success,
red representing failure, and gray representing an empty seat, can
ensure clear communication of the belt status to the customers.
Honda commented requesting clarification on the proposed
[[Page 433]]
requirement that for telltales associated with multiple front outboard
seats, the seat with which each telltale is associated must be clearly
recognizable to a driver and to any front outboard passenger. Honda
indicated that it understands the final rule to require the telltale to
use the identifying symbol or words specified in table 2 of FMVSS No.
101 and to also allow the use of a single telltale to be associated
with multiple front outboard seats. However, Honda suggested that the
``clearly recognizable'' language may be contrary to Honda's
understanding. Honda commented that it is not aware of any consumer
concerns with distinguishing the front seat positions to which this
single telltale is associated and believes that maintaining this
standardized approach will facilitate continued consumer understanding.
Honda also expressed concern about the cost burden if this requirement
cannot be met with a single telltale and concern about the extra visual
indicator overriding other warnings. Honda provided a list of telltale
designs and requested clarity regarding whether they would meet the
``clearly recognizable'' language. Honda also requested that the rule
allow for a single telltale to display all seating positions.
Agency Response
NHTSA generally agrees with the commenters who recommended that the
rule provide manufacturers flexibility, but we do believe that some
standardization of the visual warning would provide safety benefits. We
note that while many of the requirements discussed below apply only to
the rear seat belt warning, manufacturers may choose to integrate the
warnings for the front and rear, so we are presenting this material
together.
Requirements for the Rear Seat Belt Visual Warning
We disagreed with Consumer Reports and have decided to depart from
ECE R16 and not require that all rear seating positions be depicted.
While such a requirement would provide the driver with more
information, we have decided to give manufacturers design flexibility
(such as by using text, number of seats buckled/unbuckled, etc.) so
that they can decide how to optimize design for each particular
vehicle.
One situation in which this flexibility would be particularly
important is for buses and vans with many rear seats. As we explain
above (see Section VI.A.1, Applicability) one difference between the
final rule and ECE R16 is that the final rule applies to small buses
such as 15-passenger vans, while the ECE R16 rear seat belt warning
requirements do not apply to vehicles with more than 9 seats (including
the driver). As we acknowledged in the NPRM, vehicles with a larger
number of rear seats, such as passenger vans and buses, may encounter
visual signal complexities; not dictating specific types of signals
should provide manufacturers with adequate flexibility to address these
types of issues. We believe these vehicles, in particular, would
benefit from the option to indicate how many rear seats are fastened;
for example, a visual warning option for vehicles with multiple rows
would be the seat belt icon with an adjacent numeral indicating the
number of rear seat belts fastened. We recognize that such a
requirement would require more space if a manufacturer decides to
display a warning with multiple rear rows and may entail redesign of
the instrument panel or display space. We note that while one commenter
(InterMotive) indicated that it has an aftermarket solution for a rear
warning system for such higher-occupancy vehicles, NHTSA is not aware
of any new vehicles equipped with such systems. In light of the current
state of the market, we are providing two years of lead time and have
attempted to specify the final requirements in such a way as to provide
manufacturers as much flexibility as possible so that they can devise
solutions for their specific vehicles.
Similarly, with respect to the visual warning for the rear seat
belts, we have decided to finalize the proposal and permit both icons
(symbols) and text. However, we are modifying the proposal and not
specifying standardized text. We are also clarifying that numbers may
also be used in addition to symbols, and are finalizing the proposal to
standardize colors for symbols (and numbers). While we recognize that
standardized icons would help drivers recognize the icon when driving
different (multiple) vehicles, we believe there are even greater
benefits to providing manufacturers with flexibility; manufacturers can
optimize the visual warning based on the vehicle design and consumer
preferences, particularly since there are a range of different
approaches being used already. (Icons appear to be prevalent in newer
vehicles.) We have also decided to allow the use of text and/or numbers
other than what we proposed for the rear seat belt warning to afford
manufacturers as much flexibility as possible. We note that the
effectiveness of numbers depends on how well the design is executed;
for example, one commenter provided an example showing that it can be
confusing. Accordingly, manufacturers should not assume drivers will be
familiar with seat numbers when developing their warning. On the other
hand, as discussed below, we are standardizing colors to facilitate the
interpretation of the signal.
We have decided to finalize the requirements for the color of
symbols or numbers if used to indicate how many or which rear seat
belts are (not) in use. After considering the comments, NHTSA concludes
that the advantages of standardizing colors outweigh the drawbacks. We
believe that standardizing colors limits confusion and allows for
faster interpretation. We note that the FMVSS generally do not address
color blindness. Importantly, however, this requirement does not
prevent manufacturers from designing the visual warning so that it can
be perceived by colorblind consumers. For example, OEMs could design
systems using a combination of color and a positive/negative symbol.
Moreover, we agree with GM that such redundancy can aid in rapid
interpretation of the warning (glanceability). Use of a symbol without
a color would be prohibited but we believe this requirement is
warranted because use of a color would aid in faster identification of
buckled/unbuckled seats for most users. Similarly, the final rule
provides that the change-of-status visual warning may use the same
telltale as the start of trip warning, provided that the color of an
illuminated symbol or number used to indicate to the driver how many or
which rear seat belts experienced a change of status from in use to not
in use is red.
NHTSA is, however, clarifying that the proposed requirements were
not intended to prohibit the use of gray or other neutral colors or
signifiers (such as a non-illuminated indicator) to denote seats that
are unoccupied or to denote a seating position for which information
about buckle status is not being conveyed (e.g., using gray to indicate
seating positions at which the belt is fastened in a negative-only
system that does not use occupant detection). This approach is being
widely adopted in the U.S. and other markets and, in our view, is
understood by consumers. To more clearly convey our intent here, the
final rule explicitly provides that a visual warning is not required
for (1) an unoccupied seat if the system is able to determine whether
or not a seat is occupied; (2) a seat belt that is in use in a system
designed to indicate to the driver how many or
[[Page 434]]
which rear seat belts are not in use; and (3) a seat belt that is not
in use in a system designed to indicate to the driver how many or which
rear seat belts are in use. Therefore, the color requirements will not
apply to symbols or numbers that are conveying any of these three types
of information, because such information is not considered part of the
required warning.
Requirements for the Front Outboard Seat Belt Visual Warning
We have decided to finalize the proposal to maintain the FMVSS No.
101 icon for the driver's seat belt warning and extend it to the front
outboard passenger seat belt warning. We continue to believe, as we
explained in the NPRM, that this requirement is beneficial because
these visual warnings have been in place for decades and we believe
that consumers are accustomed to them. It is also in line with ECE R16,
which requires the same icon for the front seats.\183\ At this time we
therefore do not see a need to remove this requirement.
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\183\ Section 8.4.3.2.
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As stated in Section VI.B.4, in response to the comments, NHTSA has
modified the proposal so that the final rule requires that the front
outboard passenger visible warning be visible only to the driver,
except for two potential future situations where only requiring the
visual warning to be visible to the driver would not be sufficient. The
first is for dual-mode ADS-equipped vehicles that still have a driver's
seat and driving controls. For such vehicles the driver's seat could
remain unoccupied throughout the vehicle's operation. In this
situation, limiting the visibility of the front seat warnings to the
driver's seat would result in the passenger not seeing the warning. The
second is for ADS-equipped vehicles without a driver's designated
seating position. For the first, the final rule requires that the
visual warning for the front outboard passenger seat belt must be
visible from the front outboard passenger seat, and for the second the
final rule requires that the visual warning for each outboard
designated seating position be visible from each outboard passenger
seating position.
Accordingly, while we proposed that for telltales associated with
multiple front outboard seats the seat with which each telltale is
associated must be clearly recognizable to a driver and to ``any front
outboard passenger,'' the final rule instead requires that a visual
warning associated with multiple front outboard seats must ``clearly
identify the seating positions for which the warnings are intended.''
Honda's comment concerned the proposed ``clearly recognizable''
language. NHTSA clarifies that this final rule does not require a
separate telltale (i.e., a telltale with the identifying symbol
specified in table 2 of FMVSS No. 101) for each front seating position
nor does it require any particular visual warning design. We believe
that one telltale which distinguishes which position is unbuckled would
be acceptable, as would separate telltales, as long as the visual
warning clearly identifies the seating position(s) for which the
warning(s) is intended. We leave it to manufacturers to design their
systems such that they can certify in good faith that they meet the
standard, and the final rule does not further specify how to do so to
preserve that design flexibility.184 185
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\184\ It is possible to design single telltales that comply both
with FMVSS No. 101, Table 2 and the requirement that for telltales
associated with multiple front outboard seats, the seat with which
each telltale is associated must be clearly identified because FMVSS
No. 101 allows supplemental symbols and information. See S5.2.3
(``Supplementary symbols, words, or abbreviations may be used at the
manufacturer's discretion in conjunction with any symbol, word, or
abbreviation specified in Table 1 or Table 2.'').
\185\ We note that the proposed ``clearly recognizable''
language was identical to language currently found in S19.2.2 of
FMVSS 208. That language was added to the standard in a 2022 final
rule on Occupant Protection for Vehicles with Automated Driving
Systems. In the preamble to that final rule, we explained that that
provision would not permit a single telltale for both front outboard
seating positions: ``[t]he Alliance and GM requested allowing a
single telltale for both front outboard seating positions. It is
NHTSA's position that, while a single telltale unit that
distinguishes both indicators would be acceptable, a single light
indicating the suppression status of both air bag systems, but not
distinguishing their individual state of suppression would not.
Separate suppression telltales clarify which associated seating
position is suppressed, allowing the corresponding passenger to
respond to the information with appropriate action.'' 87 FR 18560.
While NHTSA continues to believe that requiring separate telltales
for two front seating positions was justified for the reasons given
in that rulemaking, after considering the comments, we believe that
it would be appropriate for this final rule to allow a single
telltale for two seating positions, as long as the visual warning
clearly identifies the seating position(s) for which the warning is
intended.
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4. Interaction With Other Vehicle Warnings
NHTSA proposed that neither the visual nor the audible component of
the seat belt warning for the both the front and rear seat belts could
be overridden by other warnings for the required durations.\186\ This
proposal was consistent with the current requirements in FMVSS No. 101
for the driver's seat belt telltale which specify, among other things,
that the seat belt telltale must displace any other symbol or message
in that common space while the underlying condition for the telltale's
activation exists.\187\ We did not believe that the seat belt warning
requirements would interfere with warnings for other safety systems
because we believed that those other warnings have dedicated warning
signals, and that manufacturers would have enough flexibility to
determine the best way to implement the various warnings. For instance,
warnings for another potential safety risk may be more aggressive than
those for the seat belts. With regard to available space, we proposed
that the visual signal might be displayed as a telltale on the
instrument panel or on the vehicle's information display screen. We
noted that manufacturers would also have to determine whether the
driver and rear passenger seat belt visual warning would be treated the
same. Neither ECE R16 nor Euro NCAP address interaction with other
vehicle warnings.
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\186\ 88 FR 61674 61742-43 (Sept. 7, 2023) (proposed front and
rear warnings at S7.5(b)(5) and S7.5(c)(5), respectively). Proposed
S7.5(c)(1)(v), which also required that the rear seat belt visual
warning not be overridden, was redundant. This issue is discussed
later in this document.
\187\ 49 CFR 571.101, S5.5.5. See also S5.5.2 (``The telltales
for any brake system malfunction required by Table 1 to be red, air
bag malfunction, low tire pressure, electronic stability control
malfunction (as of September 1, 2011), passenger air bag off, high
beam, turn signal, and seat belt must not be shown in the same
common space.'')
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Comments
A number of commenters expressed concern about the proposed
requirement that the visual warning could not be overridden. HATCI, for
example, commented that if manufacturers display the rear telltale in
the visual information screen, they would display the rear seat
pictogram in the same location often used to display advanced safety
feature warnings such as Forward Collision Warning (FCW) or Automatic
Emergency Braking (AEB) and may impede or prevent those warnings. Auto
Innovators commented that several automakers currently have warning
systems that use a contextual display diagram to provide the driver
with information on the status of passenger belt use. However, they
noted that these displays can be relatively large and necessitate
sharing limited display space in the instrument panel, and therefore
may need to be temporarily overridden to convey other safety urgent
warnings.
To address this concern, Auto Innovators, NADA, Nissan, Rivian,
Honda, and HATCI requested that NHTSA remove the proposed override
requirements, or provide a general
[[Page 435]]
exception that manufacturers have discretion to prioritize other safety
relevant warnings as needed. Auto Innovators commented that NHTSA
should harmonize with ECE R16 and remove the override requirements for
both front and rear row seating positions to provide flexibility for
manufacturers to implement in-vehicle displays such that important
information can temporarily override the reminder alert on an as-needed
basis.
Specific to the front reminder, HATCI recommended allowing a
warning displayed in the vehicle's information display screen to be
temporarily suppressed when it is necessary to alert or redirect the
driver's attention to an advanced safety warning related to vehicle
operation. On the other hand, Honda commented that the front seat belt
unfastened telltale, as currently specified in FMVSS 101, should remain
a dedicated warning that cannot be interrupted.
Auto Innovators supported providing manufacturers with the
flexibility to prioritize safety alerts for the duration that other
safety critical warnings may be required. Honda and Mercedes commented
that it is not essential for the rear seat belt visual warning to be
provided uninterrupted 100 percent of the time because it is
supplemental to the audible warning. Because of this redundancy, in
Auto Innovators' view, other critical information should be allowed to
be presented to the driver.
Honda and Auto Innovators urged NHTSA to allow visual warnings,
with the exception of the dedicated telltale currently specified in
table 2 of FMVSS No. 101, to be temporarily overridden by system
failure warnings and warnings requiring an urgent response. Honda
stated that doing so would allow existing high-visibility display
locations to convey the most urgent warning to the driver, while
retaining a baseline warning that would convey whether there is an
unbelted occupant. Honda and Auto Innovators argued that this approach
would also align with the current FMVSS No. 101 requirements prescribed
in section 5.5 where the seat belt unfastened symbol or text (``Fasten
Seat Belts'') must have a dedicated telltale, but other supplemental
warnings may be displayed in a common display space. Auto Innovators
requested additional clarification on the applicability of the override
prohibition and whether it applies to suppression of the visual
warning, audible warning, or both. It requested that both be able to be
overridden.
Honda and Auto Innovators also commented that the proposal would
necessitate several changes to systems currently deployed without any
substantiated benefit. First, Honda explained that the visible display
space for the driver, particularly the instrument cluster, is already
allocated. Therefore, the proposal would require either the
implementation of a new standalone indicator, dedicated to only the
rear seating positions, or repositioning the warning to a less ideal
area of the instrument cluster. Honda indicated an example in which it
may become necessary to minimize the seat belt warning size in order
for the warning to have a dedicated space. Honda and Auto Innovators
argued that these changes would require substantial redevelopment and
that implementing such a system within the proposed time frame would be
impractical.
Rivian commented that the proposal does not contain volume or tone
requirements for the chime. Rivian inquired about whether a change in
volume for the audible chimes during the required duration of the
warning to increase the volume of a competing safety-critical warning
would or would not constitute an override.
Finally, InterMotive commented that the proposed requirements
should not create interaction issues between different vehicle systems.
InterMotive noted that it has a product in the market that would comply
with the proposed requirements and that there have been no issues with
the product interacting with other warning systems.
Agency Response
NHTSA has decided to finalize the proposal that the visual seat
belt warning not be overridden by other vehicle warnings. However, in
response to the comments we have decided to modify the proposal and
permit the audible component of the front and rear seat belt warnings
to be overridden by certain safety-critical warnings that require the
driver to take some immediate action.
Visual Warning
We are finalizing the proposal that the visual seat belt warnings
not be overridden by other vehicle warnings. FMVSS No. 101 has long
required that the driver's seat belt visual warning not be displaced by
other warnings. We do not believe that these amendments to the seat
belt warning requirements should lead us to alter this
requirement.\188\ There are several reasons for this conclusion.
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\188\ The final rule does not prohibit manufacturers from
designing vehicles so that a crash-imminent visual warning, or other
visual warning that alerts the driver to take some immediate action,
is more prominent than the seat belt warning.
---------------------------------------------------------------------------
First, while the final rule requires an additional telltale for the
rear seat belt warning, we believe that there is sufficient room on the
vehicle's instrument panel or on the vehicle's information display
screen. Most safety telltales have a dedicated icon and display space.
In particular, we believe most critical safety warnings have dedicated
space for their respective icons/symbols. NHTSA's understanding of
contemporary vehicle designs is that they are more likely to feature a
larger combined display instead of separate instrument panels and
center stack displays, so there should be sufficient space to present
two simultaneous visual warning signals separately. Whether prohibiting
override of the seat belt warning would require redesign of the display
area depends on whether the competing warnings are supplemental. If
they are, then not allowing the seat belt warning to be overridden
would not necessarily require redesign; while the supplemental warning
could not be displayed in the space common to the seat belt warning,
the primary warning could still be displayed. However, if the competing
warning were not simply supplemental, then we acknowledge that redesign
would be necessary. If an OEM chose to redesign in such a way as to
have dedicated space for all the different warnings, we believe it
would be possible, but acknowledge it might be burdensome. However, we
believe the final rule provides manufacturers with ample flexibility in
terms of what types of warnings are allowed and not dictating a
specific location for the warning.\189\
---------------------------------------------------------------------------
\189\ With respect to InterMotive's comment, its aftermarket
product has a separate display, so it is not relevant to this
discussion.
---------------------------------------------------------------------------
Second, it would likely be rare for the seat belt warning and other
warnings to occur at the same time. With respect to the front seat belt
warning, because these systems have been in place for decades, and
because FMVSS No. 101 has long required that the driver's seat belt
visual warning not be displaced by other warnings, we believe these
visual warnings have their dedicated display space already and thus do
not warrant allowing override for other safety critical warnings
because the warnings can activate simultaneously. With respect to the
rear seat belt start-of-trip warning, given the relatively short
duration (30 seconds) and timing (ignition on or start), it should be
relatively unlikely for another safety-critical warning to be necessary
in that time. With respect to the rear seat belt change-of-status
warning, because we are requiring that the start-of-trip visual
[[Page 436]]
warning not be overridden, we believe that although a safety critical
warning may need to activate at the same time as the change-of-status
warning, the warnings will have been designed to not be in the same
space and they can both activate simultaneously.
Third, extinguishing the seat belt reminder visual warning during
other warnings might confuse drivers. If they notice that the warning
deactivates and then re-activates with no corresponding change in seat
belt status, they may believe the system is malfunctioning.
We are also declining to adopt Honda's suggestion to allow override
of the larger warning and rely on the use of the single FMVSS No. 101
front seat belt warning telltale for all seats. We believe that this
would confuse the driver, because the driver would not know what seat
the warning applies to. The current FMVSS No. 101 seat belt warning
requirements apply only to the driver's seat belt warning (with this
final rule extending them to the front outboard passenger's seat and
the rear seats), and not to other seating positions.
Audible Warning
The final rule, however, does permit the audible component of the
seat belt warnings to be overridden by certain safety-critical warnings
that require the driver to take an immediate action. As an initial
matter, we clarify that the proposal would have prohibited the audible
component of the reminder from being overridden as well as the visual
component.\190\ The proposed regulatory text contained a redundant
provision that required that the rear seat belt visual warning not be
overridden by other visual warnings that was likely the source of
confusion.\191\ However, in response to the comments, NHTSA has decided
to permit the seat belt audible warning to be overridden by certain
warnings. Specifically, NHTSA believes it is reasonable to allow a
pause in the audible seat belt warning to allow for a safety critical
warning that requires the driver to take some immediate action. This
includes crash avoidance warnings that require immediate action by the
driver, such as braking or steering. With respect to Rivian's comment,
a change in volume of the chime would not constitute an override of the
warning because the final rule does not regulate audible warning
volume. See Section VI.C.5, Audible Warning Characteristics.
---------------------------------------------------------------------------
\190\ See 88 FR 61674, 61742 (Sept. 7, 2023) (Proposed
S7.5(b)(5) and S7.5(c)(5)).
\191\ See 88 FR at pg. 61743 (Proposed S7.5(c)(v)).
---------------------------------------------------------------------------
5. Audible Warning Characteristics (Other Than Duration)
The NPRM proposed a variety of specifications for the audible
warnings. The proposed requirements were different for the front and
rear audible warnings.
For the rear change-of-status warning (which had a minimum required
duration of 30 seconds), we proposed that the audible signal could be
intermittent or continuous and that if intermittent, inactive periods
longer than 3 seconds would not be counted toward the total duration of
the audible warning. We did not propose to specify minimum duty cycle,
chime frequency, or warning cycle.
For the front seat belt audible component of the start-of-trip and
change-of-status warnings, we proposed more detailed requirements than
for the rear seat belt audible warning because the minimum duration was
much longer (essentially until all front outboard occupants were
belted, for both the start-of-trip and change-of-status warnings). We
proposed that the front seat belt audible warning may be continuous or
intermittent. If intermittent, we proposed that, when active, the
audible warning must be continuous or have a chime frequency of at
least 0.5 Hz and a duty cycle of at least 0.2. The proposal defined,
for an intermittent audible warning, the terms warning cycle, chime
frequency, and duty cycle. The proposal defined ``warning cycle'' as
consisting of period(s) when the warning is active at the chime
frequency or continuously, and inactive period(s). A warning cycle
would begin with an active period and would be 30 seconds in duration.
``Chime Frequency'' meant the repetition rate for an intermittent
audible warning when the warning is active. ``Duty Cycle'' meant the
total amount of time an intermittent audible warning is active during a
warning cycle at the chime frequency or continuously, divided by the
total warning cycle duration (30 seconds). These requirements were
largely based on the results of a 2012 IIHS study on duty cycles.\192\
IIHS test protocols do not specify a duty cycle. We proposed that the
same audible warning may be used for all seats. We did not propose a
limit on the maximum duration of audible gaps for the purposes of
determining the warning's total duration because we did not propose a
finite minimum duration.
---------------------------------------------------------------------------
\192\ Kidd, D.G. (2012). Response of part-time belt users to
enhanced seat belt reminder systems of different duty cycles and
duration. Transportation Research Part F, 15, 525-534.
---------------------------------------------------------------------------
These proposals deviated from Euro NCAP and ECE R16's
specifications in some ways. Euro NCAP specifies that for the front
seats the audible signal must not have gaps greater than 10 seconds,
and that gaps longer than 3 seconds would not count toward the
warning's total duration. The final audible signal must be ``loud and
clear'' for the driver. The 10 second limit, in addition to its
specification of a 3 second gap limit toward the calculation of the
warning's total duration, would not be sufficient to ensure a 0.20 duty
cycle warning. ECE R16 also does not count warning gaps longer than 3
seconds toward the required minimum warning duration requirement.
Comments
Auto Innovators and NADA requested that NHTSA harmonize with ECE
R16, which provides increased flexibility for manufacturers determining
the characteristics of both front and rear row belt reminder alerts.
Auto Innovators recommended that the agency avoid defining
characteristics (such as the warning and duty cycles) that would
prevent a manufacturer from implementing different alerts such as
escalating alerts.
Mercedes commented that its current seat belt reminder system
design starts a baseline alert once the criteria have been met; if the
conditions of the seat belts at the occupied seats have not changed
after 30 seconds, the system will escalate the warning. Mercedes stated
that this approach does not cause excessive annoyance to drivers and
does not negatively affect the efficacy of the warning system. Mercedes
urged NHTSA to remove the continuous series requirement for
manufacturers to develop systems with effective escalating alerts.
Consumer Reports also commented that audible warnings should escalate.
Honda sought clarity on the ``warning cycle'' requirements as
proposed. Additionally, it encouraged the agency to consider whether
adopting a warning that is continuously active (i.e., 100 percent duty
cycle) for a definite duration of 90 seconds would be as effective as
the proposal to require an indefinite warning with a minimum duty cycle
of 20 percent. Honda explained that its experience is that a continuous
90-second chime is sufficiently persistent and might offer greater
effectiveness compared to an indefinite warning that delivers only a 6-
second chime followed by a 24-second pause between chimes. IIHS,
identifying the same concern, urged NHTSA to require auditory signals
to be separated by no more than 3 seconds in addition
[[Page 437]]
to requiring a minimum 20 percent duty cycle.
IIHS, supported by MADD, Advocates and Public Citizen, and the
National Association of Mutual Insurance Companies (NAMIC), requested
that NHTSA set minimum requirements for the volume and fundamental
frequency of an auditory reminder to ensure it is ``loud and clear''
and will be noticed by vehicle occupants. IIHS provided supporting
materials for the volume and fundamental frequency minimums that it
requires. It also commented that NHTSA should require the same auditory
reminder characteristics (e.g., volume, fundamental frequency, gap
between signals, duty cycle) for the front and rear rows. It stated
that consistency makes the requirements easier to implement for
automakers, easier for consumers to understand, and would align with
current practice.
Agency Response
After reviewing comments, we are finalizing the proposed audible
warning requirements for both the front and the rear warnings with
minor changes. The first change is that the front start-of-trip warning
now must meet only the same minimum requirements as the rear change-of-
status warning, because both are time-defined. The second change is
that we are adding a 10-second maximum gap limitation, similar to Euro
NCAP, to both of these warnings. Because this final rule requires that
gaps longer than 3 seconds do not count toward the required duration
for these two warnings, without a maximum gap limitation there would be
no limit on the amount of time it would take for the warning to reach
the 30 second minimum cumulative warning duration. Allowing audible
warnings that take too long to meet the 30 second minimum cumulative
warning duration could degrade the effectiveness of the warning. We
also believe that this requirement will not impede the manufacturer's
design flexibility significantly and that these parameters meet the
need for safety, are objective, and are practicable, because they
provide an acceptable minimum level of effectiveness while allowing
manufacturers latitude to optimize the warning for effectiveness and
vehicle occupant acceptance. We continue to believe that the parameters
stated for the front second phase warning--warning cycle, duty cycle,
and chime frequency--are essential for an indefinite warning to meet
the need for safety. Similarly, we believe that the 30-second front
start-of trip-warning and rear change-of-status warning will be
effective with the specified signal gap limitations.
We have concluded that specifying minimum requirements for chime
frequency and duty cycle for the second phase front audible warning is
critical for ensuring a minimum baseline of effectiveness. This
approach is based on the existing research which suggests that warning
signal characteristics--such as duty cycle, frequency, volume, or
timbre--can be adjusted to balance effectiveness and consumer
acceptance but also shows that there is a minimum level of
effectiveness provided by requiring a 30-second repeating warning
cycle, with a minimum 0.5 Hz chime frequency and a 20 percent duty
cycle.\193\ Because ECE R16 requires very short time-defined alerts for
the front seat belt warning (30 seconds), a duty cycle requirement is
not necessary. We are incorporating a duty cycle requirement because in
the context of an indefinite warning this requirement ensures a minimum
time that the audible warning chime will be active. Additionally, we
are not incorporating one of the approaches taken by ECE R16 and Euro
NCAP to limit gaps in the audible warning (that gaps longer than 3
seconds would not count toward the warning's total duration) because we
do not have research suggesting that it would increase effectiveness.
Additionally, a sole requirement that gaps longer than 3 seconds would
not count toward the warning's total duration would be inadequate in
the context of an indefinite warning. Therefore, at this time, the
agency is making the judgement that specifying a maximum signal gap of
3 seconds, either with or without a duty cycle, unnecessarily limits
manufacturer's flexibility for the speed-initiated warning. Finally,
this final rule does not prevent the design of escalating alerts, as
some manufacturers such as Mercedes suggested in their comments. The
duty cycle and chime frequency are minimum requirements, and the
warning cycle specification does not require each cycle to be
identical. Manufacturers may design escalating alerts within the
minimum requirements of this final rule.
---------------------------------------------------------------------------
\193\ Id.
---------------------------------------------------------------------------
Additionally, given the required duty cycle for the front
indefinite warning, we do not need to incorporate a maximum signal gap
(i.e., no gaps longer than 10 seconds) like the one used by Euro NCAP.
Some comments suggested that the proposal contained a flaw: that given
the 20 percent duty cycle and 30 second warning cycle requirements,
this rule would allow a warning that was active for 6 seconds, with a
24-second gap. However, this was not an error. Commenters did not
demonstrate that the proposed warning would be ineffective, and that
notion is inconsistent with available data. Increasing the duty cycle
would, after a point, cause a reduction in signal gaps, even if no
specific signal gap limitation were required. Therefore, if those
commenters were correct, and the gap in the signal were a meaningful
characteristic, we would expect higher duty cycles to increase
effectiveness. However, the 2012 IIHS study on duty cycles, referenced
in the NPRM, indicated that there was not a statistically significant
difference in effectiveness between the 20 percent, 50 percent, and 100
percent duty cycles, which cycled over 30 second warning periods. This
suggests that beyond the maximum gap established by a 20 percent duty
cycle, reducing the gap does not increase effectiveness. Without
demonstrable safety benefits, such a limit would unnecessarily restrict
manufacturers' design flexibility. Therefore, we are not specifying a
maximum signal gap in this final rule for the front seat belt
indefinite warning. Only the time-defined front start-of-trip warning
and the rear change-of-status warning have a signal gap rule (that gaps
longer than 3 seconds would not count toward the warning's total
duration) and maximum signal gap requirement (10 seconds). Importantly,
meeting the requirements of this rule does not preclude designing an
alert that complies with the signal gap rules in ECE R16. As an
example, with a 20 percent duty cycle requirement and a gap duration of
3 seconds, a compliant alert could be active for at least 0.75 seconds
regardless of the chime frequency.\194\
---------------------------------------------------------------------------
\194\ This was calculated as follows: (0.2 = 0.75/(3 + 0.75)
(duty cycle is the total amount of time an intermittent audible
warning is active (.75 seconds) divided by the total warning cycle
duration (time active plus the duration of the gap)).
---------------------------------------------------------------------------
With regard to requests to harmonize the requirements for the front
and rear audible alerts, we do not believe it is necessary to require
that the alerts have the same minimum characteristics across seating
positions. Instead, we structured this final rule so that
manufacturers, if they choose, may design one audible alert that
complies with the requirements for both the front and rear alerts. We
also continue to believe that given the short duration of the rear
change-of-status warning, it is not necessary to specify
characteristics such as duty cycle, chime frequency, and warning cycle.
As we stated in the
[[Page 438]]
NPRM, we believe establishing minimums for these characteristics is
primarily needed for longer or indefinite alerts to ensure that the
warnings have at least a minimum level of persistence. As such, since
we have revised the requirements for the front seats so that the start-
of-trip warning is required only to be at least 30 seconds long, we
have decided that the audible portion of the start-of-trip warning
should be subject to the same characteristics as the rear change-of-
status warning. Therefore, as mentioned above, for consistency we are
finalizing for both the front start-of-trip warning and the rear
change-of-status warning only that inactive periods longer than 3
seconds would not be counted toward the total duration of the audible
warning and that there be no gaps in the warning greater than 10
seconds. The proposed minimum characteristics for the audible component
of the front seat belt warning, as finalized, will now only apply to
the audible front seat second phase warning.
Finally, we are not incorporating the specifications for volume and
frequency IIHS suggested. We have designed the final requirements to
give manufacturer the flexibility to design warnings that are both
effective and acceptable to consumers. We believe that sound volume and
frequency can be used by manufacturers to make their warnings more
effective and/or more acceptable, which is particularly important for
an indefinite warning. Similarly, we are skeptical that a volume
specification is needed because it has never been needed in the past.
Since the early 1970s, FMVSS No. 208 has required an audible driver's
seat belt warning with no additional audible warning requirements and
manufacturers have been designing and implementing warnings under that
structure without issue. Additionally, regarding frequency, IIHS
indicated that nearly all systems tested already meet their suggested
specification, so a regulatory requirement may not be needed.
Nonetheless, as the new requirements are implemented, the agency will
monitor these characteristics and assess whether additional rulemaking
action is warranted.\195\
---------------------------------------------------------------------------
\195\ Accordingly, we explain in Section VI.C.4, Interaction
with other vehicle warnings, that a change in the volume of the
audible warning would not constitute an override of the warning.
---------------------------------------------------------------------------
6. Warning Deactivation and Acknowledgement and Hardening
In the NPRM, we proposed not to allow features which would permit
the driver to acknowledge the warning and cancel it before the end of
the required duration or to deactivate the warning for an entire trip
or for a specified time period (thus preventing it from activating in
the first place).\196\ We also did not propose requiring features to
harden the system against circumvention due to concerns about the cost
and effectiveness of such features. We sought comment on both issues
and whether these features would impact the effectiveness of the rule.
---------------------------------------------------------------------------
\196\ 88 FR 61674, 61704 (Sept. 7, 2023).
---------------------------------------------------------------------------
ECE R16 allows both short-term and long-term deactivation of the
audible warning (with a variety of restrictions, such as that it be
more difficult to effectuate a short-term deactivation than to buckle
the belt). Euro NCAP does not provide any specifications for
deactivation or acknowledgement of the warnings for the front seats; it
allows acknowledgement only of warnings for rear seats, except for
change-of-status warnings. Neither ECE R16 nor Euro NCAP requires
hardening features.
Comments
Some commenters suggested making the visual warning, audible
warning, or both dismissible, and presented a variety of approaches.
For example, Auto Innovators and HATCI suggested harmonization with
IIHS and ECE R16. HATCI specified making the dismissal procedure more
complex than buckling the belt. NADA noted that dismissal or
suppression would help address consumer acceptance concerns with the
indefinite warning. Auto Innovators also suggested allowing
deactivation of the audible rear seat warning. Auto Innovators believes
that this approach would minimize potential consumer acceptance issue
in circumstances where there may be a frequent change in the status of
rear row occupancy and movement of occupants between seating positions
such as ridesharing. Rivian recommended that NHTSA permit a reset or
discontinue feature for instances in which a system with occupant
detection detects that a seat becomes or is unoccupied to clear the
audio-visual warning for front and rear occupants who exit the vehicle.
Consumer Reports commented that it would be reasonable to allow drivers
to ``acknowledge and dismiss'' warnings on a trip-by-trip basis to
address drop-off situations, seat position changes, and situations
involving fastening the wrong buckle.
Anonymous #24 and Anonymous #33 commented that a potential issue
with the rear seat belt warning systems is the frequency with which
individuals use rear seat space for storage or transportation of items
large enough to trigger a seat belt warning system. Accordingly,
Anonymous #24 argued that there should be an option for the vehicle
operator to dismiss the warning in situations in which the seat belt
reminder system is triggered by items other than people in the rear
seat.
Regarding hardening features, Auto Innovators and HATCI did not
support additional hardening features due to the added technical
complexity and implementation cost that would be required to reduce the
potential for intentional and inadvertent defeat and activation.
On the other hand, Ms. Tombrello commented that it is important to
address occupants who may intentionally try to circumvent seat belt
reminder systems such as a scenario in which seat belts are buckled
while passengers sit on top of the belt.
GM commented that NHTSA should also consider allowing suppression
or dismissal of the front seat reminder audible warning in specialty
vehicles such as police cars to allow for cases where the officer needs
to communicate, whether with other law enforcement, first responders,
or on radio devices, without the interference of background chimes in
the vehicle.
Agency Response
The final rule does not allow deactivation or acknowledgement and
dismissal of the front or rear seat belt warnings. As 87.7 percent of
front seat occupants already always use their seat belts, the large
majority of the overall population will not encounter the indefinite
warning and, therefore, are unlikely to find it annoying. Furthermore,
based on the Kidd and Chu study, we have at the very most only 8.4
percent (5.4 percent (never users) + 3.0 percent (44 percent x 6.9
percent of sometimes users)) of the total population that would not be
accepting of this as a standard feature. Therefore, allowing
deactivation or acknowledgement and dismissal, would reduce safety
benefits of the final rule even though there is general acceptance of
this feature. Even temporary dismissal can reduce effectiveness by
increasing the time before a change-of-status situation is addressed.
Additionally, warnings lose effectiveness if drivers regularly dismiss
the warning. Instead of deactivation or dismissal, this final rule
contains multiple provisions and changes from the NPRM designed to
maximize consumer acceptance while retaining the effectiveness of the
belt warnings. The alerts required are now either short duration (for
which driver annoyance is low) or are active in situations where
[[Page 439]]
belt use is critical. For instance, the start-of-trip audible warning
system for the front seats and the change-of-status audible warning
system for the rear seats now only have a 30 second minimum duration,
which is short enough to have only a limited consumer annoyance impact.
An indefinite duration audible warning is required only for front seats
for speeds at or over 10 km/h (6.2 mph), at which point allowing
deactivation or dismissal not only reduces effectiveness but defeats
the purpose of an indefinite alert. There is also a variety of
research, cited throughout this document and in the NPRM, regarding the
high level of consumer acceptance for seat belt warning systems.
Additionally, a few commenters such as Consumer Reports brought up
scenarios that may generate false warnings, such as passenger pick-up
and drop-off, or rear seat occupants switching seats during a trip, for
which they argued that driver deactivation (or dismissal) is the
appropriate response. This comment does not convince the agency that
deactivation or dismissal is needed because in this final rule we have
addressed many of these scenarios through other means. Regarding
passenger pick-up and drop-off, this final rule allows systems to treat
a door opening as the start of a new trip, resetting the change-of-
status warning for the rear seats. For the front seats, the finalized
requirements require only a visual change-of-status warning (assuming
that, because the vehicle is stopped in a pick-up and drop-off
scenario, the second phase warning would not activate), but the door
reset provision would still apply to that visual change-of-status
warning. For seat-switching in the rear, this final rule now contains a
provision allowing a system to deactivate the warning if the system has
determined that rear occupants have switched seats.
We also received comments regarding items placed on the rear seat,
which is addressed elsewhere in this final rule. We note here that this
rule does not preclude designs that do not activate a passenger seat
belt warning if the seat belt is fastened and no one is in the seat.
Thus, nuisance warnings due to cargo could be prevented by buckling the
seat belt or placing the cargo somewhere else. NHTSA understands that
these provisions may not account for all scenarios and warnings may
still cause some unneeded annoyance. However, we believe that this rule
properly balances effectiveness with consumer acceptance. Therefore,
NHTSA is not going to allow deactivation or dismissal in this final
rule.
We also note two items in response to some commenters' requests to
harmonize with ECE R16 to allow deactivation and dismissal of front
warnings. First, regarding the visual alert, this final rule is
harmonized with ECE R16 in that it does not allow dismissal. This is in
part because visual warnings cause little annoyance to the driver and
have a low impact on consumer acceptance. Second, commenters such as
NADA stated that their reasons for seeking harmonization on
deactivation or dismissal centered on consumer acceptance grounds. As
noted, these concerns have largely been addressed through other means.
Additional harmonization may reduce this rule's effectiveness even if,
as some commenters suggested and ECE R16 requires, the rule were to
require a short-term deactivation to be more difficult than buckling
the belt. Therefore, we have determined not to harmonize on
deactivation or dismissal of the audible warnings.
We have also decided not to incorporate required hardening features
or features to prevent circumvention of the system because, as some
commenters pointed out, they increase the cost and complexity of
warning systems without providing corresponding benefits. Although
these requirements could increase benefits for the hardcore belt non-
users, these benefits are unclear because most rear seat belt non-users
are not hardcore and are less likely to intentionally circumvent the
warning system.\197\ We note that manufacturers do have the discretion
to incorporate such features if they choose to. This decision
harmonizes with ECE R16 and Euro NCAP, which do not require such
features.
---------------------------------------------------------------------------
\197\ Highway Loss Data Inst., Ins. Inst. for Highway Safety,
Unbelted: Adults Admit They Often Skip Belts in Rear Seat, 52 Status
Rep. 1, 3 (Aug. 3, 2017).
---------------------------------------------------------------------------
Finally, we are not including a deactivation provision for the
front seat belt warning specific to law enforcement vehicles. FMVSS No.
208 has required a warning system for the driver's seat in law
enforcement vehicles for many years without issue. Commenters did not
suggest that extending the requirement to the front outboard passenger
seat would create a concern. NHTSA understands that there may be
additional considerations for law enforcement vehicles given some of
the changes to the audible alert itself in this rule. However,
currently NHTSA does not believe these considerations are sufficient to
change the requirements specific to such vehicles. Like emergency
vehicles, these vehicles are often modified by the purchaser to
accommodate specific concerns, and the FMVSS do not prohibit such
purchaser modifications. As with emergency vehicles, NHTSA will also
monitor the situation and can modify this approach in future rulemaking
actions, if necessary.
7. Vehicles With Automated Driving Systems
In the NPRM, NHTSA proposed incorporating certain language to
tailor aspects of this rule to vehicles with ADS, which may be designed
differently, to maintain the same level of occupant protection in
vehicles equipped with ADS as in conventional vehicles. For example,
such vehicles may not have a driver's designated seating position or
may have multiple front outboard passenger seating positions.
Therefore, we proposed that the front passenger warning apply to
``any'' front outboard passenger. The addition of the term ``any''
makes it clear that, in some vehicles, there may be more than one front
outboard passenger seating position. We also noted that in a dual-mode
vehicle, the left front seat is still by definition a driver's seat,
regardless of the operational status of the vehicle, so a provision to
just have a warning for the driver and right outboard passenger would
be sufficient to assure that all front seat outboard occupants receive
a warning. Additionally, because some ADS-equipped vehicles have one or
no front outboard passenger seats, we also proposed to align this final
rule with the 2022 final rule updating occupant protection standards to
incorporate considerations for vehicles with ADS and apply the same
seat belt warnings for front inboard passenger seats as front outboard
seats. Finally, we noted that NHTSA was not prepared to propose a
solution for the visibility of rear seat belt warnings for ADS-equipped
vehicles and that it was beyond the scope of the proposed rule.
Comments
AVIA commented that as NHTSA continues to promulgate safety
standards to integrate emerging technologies into motor vehicles, AVIA
encourages the agency to ensure that any new regulatory requirements
include considerations for how autonomous vehicles can meet those
standards.
Tesla supported the proposed warning on vehicle start up for front
outboard passenger seats because it aligns with manually driven
vehicles as well as partial and full automation, but
[[Page 440]]
asked how the change-of-status warning for front seats requirement will
be applied to autonomous vehicles.
Agency Response
We have added language to tailor aspects of the rule for vehicles
with automated driving systems in order to maintain the same level of
occupant protection as this final rule requires for conventional
vehicles. Some of these elements are discussed in other sections of
this document specific to aspects of the rule. For example, in Section
VI.B.4 we discuss an exception to the front seat visual warning
visibility requirement that is necessary for dual-mode ADS and in
Section VI.B.5 we address occupant detection as it relates to dual-mode
ADS. Here, we note a few additional items.
First, we are finalizing without change two items from the NPRM:
one, to apply the front seat belt warning requirements to ``any'' front
outboard designated seating position and two, to apply the same seat
belt warnings for certain front inboard passenger seats as front
outboard seat. We did not receive comment specific to these items
intended to accommodate vehicles with ADS that may not have
conventional seating configurations.
Second, to accommodate other changes in the final rule, we have
included language regarding telltale visibility as applied to certain
vehicles with ADS to maintain the same level of occupant protection as
this rule requires for conventional vehicles. As noted in Section
VI.B.4, this rule requires the front outboard passenger seat belt
visual warning to be visible only to the driver. Additionally, this
final rule requires that for telltales associated with multiple front
outboard seats, the seat with which each telltale is associated must
clearly identify the seating positions for which the warnings are
intended. This requirement is discussed further in Section VI.C.3. As
many commenters pointed out and we explained, in vehicles with a
driver, the front outboard passenger can receive the audible signal and
the driver can communicate the additional information provided by a
visual signal to the front outboard passenger. However, in vehicles
with ADS, there may not be a driver's designated seating position with
a human driver who can receive and communicate this information.
Instead, as we noted in the NPRM, in a vehicle without manually
operated driving controls, one of the front passengers may be
performing the management role for the duration of a trip, such as in
the case of a parent and children. In this circumstance, the most
appropriate recipient of the visual warning is likely to be a front
passenger.
For these reasons, we are finalizing two provisions. First, we are
finalizing as proposed that for vehicles that do not have a driver's
designated seating position, the visual warning for each front outboard
passenger designated seating position must be visible from each front
outboard passenger designated seating position. Second, we are now
requiring that for vehicles without a driver's designated seating
position, for telltales associated with multiple front outboard seats,
the seats with which each telltale is associated must clearly identify
the seating positions for which the warnings are intended. These
requirements maintain the same level of occupant protection as is
required for conventional vehicles and is also consistent with the
logic of the NPRM.\198\
---------------------------------------------------------------------------
\198\ As discussed in Section VI.B.4, many commenters expressed
concerns with redesign costs associated with a requirement that the
telltale be visible to the passenger. Although NHTSA sought comment
on aspects of the NPRM regarding vehicles with ADS, commenters
focused their concerns on conventional vehicles. Therefore, NHTSA
does not believe that such concerns are present to the same degree
with vehicles without a driver's designated seating position.
---------------------------------------------------------------------------
As we stated in the 2022 final rule on occupant protection for
vehicles with ADS, these requirements are intended to apply only to
ADS-equipped vehicles that have seating configurations similar to non-
ADS vehicles, i.e., forward-facing front seating positions
(conventional seating). As we stated in the 2022 final rule, additional
research is necessary (some of which is currently underway) to
understand and address different safety risks posed by vehicles with
unconventional seating arrangements (e.g., rear-facing seats or
campfire seating), including with regards to seat belt reminder
systems.\199\ Therefore, as we stated in Section VI.B.3 of this
document in response to AVIA's comment about front seat occupants
exiting through a door not adjacent to their seat, considerations for
vehicles with unconventional seating (and other related considerations,
such as bi-directional vehicles) are out of scope of this final rule.
Additionally, as noted in the NPRM, the visibility of rear seat belt
warnings for ADS-equipped vehicles is also out of scope of this final
rule because further research is needed before the agency proposes a
solution. Research on this topic is underway.
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\199\ 87 FR 18560.
---------------------------------------------------------------------------
Finally, we believe the final rule has addressed in prior sections
Tesla's concern about change-of-status warnings for front seats in
vehicles operating in an automated state.
8. Test Procedures
In the NPRM, NHTSA proposed that NHTSA could test any system under
any combination of seat occupancy or seat belt use status. The proposed
test procedures also specified how the agency would test a seat belt
warning system with a designated seating position that is occupied. The
finalized occupancy criteria (the test dummies and the height and
weight criteria for human beings, to be used instead of test dummies at
the manufacturer's option, that will be used to determine occupancy)
are discussed in Sections VI.A.2.a.iv (rear) and VI.B.5 (front
passenger). The NPRM also proposed that to pass the test, the human
beings or test dummies used would be seated, the seat belt use and
ignition conditions would be applied, and the required signals must
operate (that is, either activate or not activate) accordingly. The
test could be conducted with the seat and adjustable belt anchorages in
any position. The NPRM also noted that for rear designated seating
positions with occupant detection, the agency would perform the test
with the seat in any position, the seat back in the manufacturer's
nominal design riding position, and any adjustable anchorages in any
position.
Comments
Auto Innovators requested that NHTSA publish the proposed test
procedures used to evaluate vehicle compliance before issuance of the
final rule. Auto Innovators stated that this request is particularly
relevant given the differences in the requirements in the NPRM when
compared to the current requirements of ECE R16, and stakeholders'
desire for the opportunity to address any technical concerns before the
rule or test procedure is finalized. In particular, Auto Innovators
sought additional information regarding how NHTSA will evaluate the
performance of an indefinite alert.
Auto Innovators also commented that the agency should more closely
align its requirements with ECE R16 and Annex 18 to reduce test burden
costs, in particular regarding the process for evaluating the
conditions for warning activation. Auto Innovators also commented that
the proposal increases the complexity of evaluating vehicle compliance
and may require specialized equipment or similar measurement devices to
verify the characteristics of the proposed audible warning.
Finally, Auto Innovators recommended that NHTSA ensure a technology
neutral approach, both for performance requirements and test
[[Page 441]]
procedures, towards the means used to determine occupant detection.
Agency Response
The final rule incorporates several changes to the proposed
regulatory text for the test procedures:
Definition of ``seat centerline''--Both the proposed and
finalized test procedures specify the seating of the test dummy by
reference to the ``seat centerline.'' The final regulatory text
includes a definition of this term.
Occupancy criteria--The proposed regulatory text specified
these in the definitions section. In the final rule these have been
moved to the test procedures section and edited for clarity.
Test procedures--The final rule clarifies several aspects
of how the test may be carried out. The final rule does not include the
proposed specification that if a human occupant is used for testing,
that they be dressed in a cotton T-shirt, full length cotton trousers,
and sneakers, instead we are specifying that the dummy or human
occupant may be clothed in any manner because clothing should not
change the performance of the system. With respect to carrying out
testing, the proposed regulatory text simply stated, ``Place the
ignition switch in the ``on'' or ``start'' position and verify that the
seat belt warnings function as specified in S7.5(b) and S7.5(c), for
any combination of seat belt use or seat occupancy at any designated
seating position(s).'' The final rule clarifies that NHTSA could test
any of a number of test parameters: ``Verify that the seat belt
warnings function as specified in S7.5(b) and S7.5(c), for any
combination of seat belt use (at any seating position), seat occupancy
(at any seating position), removable seat electrical connection status
(connected or not connected, for any removable seat), vehicle speed,
and door status (open or closed, for any door), except that the door
shall not be opened when the vehicle is in motion.''
NHTSA is not publishing the compliance laboratory test procedures
before publishing this final rule as requested by Auto Innovators. To
investigate whether specific vehicles or products comply with the
FMVSS, NHTSA's Office of Vehicle Safety Compliance (OVSC) contracts
with labs to conduct compliance testing. OVSC laboratory test
procedures are prepared for the limited purpose of use by contracted
independent laboratories conducting compliance tests for the OVSC. OVSC
laboratory test procedures are distinct from regulatory test procedures
that are included as part of most FMVSS. OVSC laboratory test
procedures are generally based off of the regulatory test procedures in
specific FMVSS but are prepared by the agency to give contracted labs
specific instructions on how to conduct a specific test. The OVSC
laboratory test procedures are simply agency guidance for contracted
labs and do not constitute official agency action (e.g., a rule). In
some cases, the OVSC laboratory test procedure, or the report produced
as a result of the work performed by the contracted laboratory, does
not include all of the various FMVSS minimum performance requirements.
Because the OVSC laboratory test procedures are not part of the
regulation, NHTSA is not required to publish them prior to or with this
final rule. Typically, NHTSA will publish the OVSC laboratory test
procedures on its website for transparency. NHTSA plans to publish the
OVSC test procedures for this rule in the future.
NHTSA also declines to specify in the FMVSS the exact amount of
time that it will test the indefinite front outboard seat belt
warnings. NHTSA believes that specifying a finite testing duration
would weaken the rule by enabling systems that are not indefinite to
meet the test. Manufacturers must certify that their products comply
with all applicable FMVSS, and they determine what steps are necessary
to ensure that every product manufactured meets the applicable
requirements. The procedures in this rule are sufficiently detailed and
objective for manufacturers to self-certify that their systems meet the
indefinite warning requirement.
NHTSA agrees with Auto Innovators that this final rule should be
technology neutral toward occupant detection, and this rule is
technology neutral. As discussed in Section VI.B.5, this final rule
does not require occupant detection capability for the driver's
designated seating position. It provides manufacturers the flexibility
to optionally choose to certify compliance to the same occupant
detection criteria applied to the outboard passenger seats.
Additionally, while the final rule requires occupant detection
capability for the front outboard passenger designated seating position
and specifies seat occupant criteria for testing front outboard
passenger designated seating positions and rear designated seating
positions, it does not specify the methods that must be used to detect
occupancy. Manufacturers may choose occupant detection technologies at
their discretion, so long as they can certify that the vehicle meets
the requirements of this final rule and the test procedure it
specifies. The same is true for the technology that OEMs may use to
detect whether the seat belt is in use.
Throughout this final rule NHTSA has considered harmonization and
has taken care, where possible, to incorporate performance requirements
and test procedures that can enable systems to also meet ECE R16
requirements to minimize testing and compliance costs for
manufacturers. Therefore, while this final rule does not fully align
with the test procedures in ECE R16 Annex 18, they are largely
compatible. As noted in the NPRM, ECE R16 operates in a type approval
regime, while the FMVSS use self-certification and must be objective.
For this reason, the final rule departs from Annex 18 when necessary to
ensure that it is objective. Because of these necessary differences to
meet statutory obligations, full alignment of the test procedures is
not achievable.\200\
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\200\ The Safety Act establishes a self-certification process in
which vehicle and equipment manufacturers certify that their
products comply with all applicable FMVSS, which establish minimum
performance standards that the product must meet. It is up to
manufacturers to determine what steps are necessary to ensure that
every product manufactured meets or exceeds the applicable
requirements before the products are imported, sold, offered for
sale, or introduced into interstate commerce in the United States.
---------------------------------------------------------------------------
Finally, with respect to Auto Innovators' concern about specialized
test equipment needed to verify compliance with the required audible
warning characteristics, this final rule does not establish test
procedures that necessitate specialty equipment that laboratory test
facilities would not already have readily available (e.g., a stopwatch)
to verify compliance of the audible warnings.
VII. Regulatory Alternatives
In the proposal, NHTSA considered several major alternatives:
harmonizing with the standards set in ECE R16 and Euro NCAP; requiring
occupant detection and enhanced warning signals for the rear seat belt
warning; requiring a warning for the front center seat; requiring an
audio-visual seat belt warning for the front outboard seating positions
with a duration not less than 90 seconds; and a few non-regulatory
alternatives. For three of these alternatives (rear-seat occupant
detection, front center seat warning, and 90-second front warning),
NHTSA quantified the costs and benefits (see Section VIII.B). Although
the proposal followed ECE R16 and Euro NCAP in a variety of ways, it
also deviated from them in some important respects. The NPRM explained
this deviation in detail. The NPRM also explained NHTSA's tentative
reasoning for not
[[Page 442]]
selecting the other regulatory alternatives.
Comments
NHTSA received many comments concerning the regulatory
alternatives. Comments regarding alternatives for specific aspects of
the proposal are discussed throughout the preceding sections of the
preamble. Many of these comments concerned harmonization with the
relevant provisions in ECE R16, Euro NCAP, and the IIHS protocol.
Safety advocates in several instances favored final requirements that
would be more stringent or demanding than those requirements or
protocols. On the other hand, industry commenters generally--although
not always--commented in support of greater alignment with them. In
this section, NHTSA summarizes and addresses comments that concerned
harmonization generally, as well as comments concerning non-regulatory
alternatives.
In addition to the more specific comments already addressed in this
document, several industry commenters commented more generally in favor
of harmonization with ECE R16 and Euro NCAP. Auto Innovators, Hyundai,
HATCI, IEE, NAMIC, and Nissan commented in support of harmonizing the
requirements with ECE R16 and Euro NCAP. Auto Innovators commented that
harmonization with ECE R16 provides the agency with the greatest
opportunity to ensure an objective and practical approach that meets
the need for safety, while also minimizing regulatory burden and
corresponding delays associated with developing region-specific
features for the U.S. market. Auto Innovators expressed concerns with
several areas where the agency has proposed alternatives to the
requirements of ECE R16, which have already been widely adopted and
implemented in other global markets. Auto Innovators argued that
several fundamental aspects of the proposal (such as the triggering
conditions) differ from the systems that consumers may have experienced
in both previous and current model year vehicles and would result in
significant negative pushback from the public if the final rule is
adopted without change.
Hyundai similarly commented that although it supported the
proposal, its largest caveat to full support was the proposal's
departure from ECE R16's requirements. Hyundai characterized these
differences as minor in the sense that they do not represent any
fundamental change to the core elements or safety benefits of NHTSA's
proposal but stated that these ``minor'' differences could have
significant adverse implications with respect to safety benefits,
customer acceptance, unnecessary country-specific designs, costs, and
required lead times. Hyundai commented that the benefits of
international regulatory harmonization have been recognized and
espoused by government and industry organizations, including NHTSA, for
many years. Hyundai argued that these benefits include improved
regulatory and NCAP provisions that reflect the international consensus
of leading government and industry experts, more efficient development
and timely enactment of state-of-the-art vehicle safety provisions,
enabling international trade and cooperation by reducing nontariff
barriers, more effective use of finite government and industry
resources, avoidance of country-specific requirements, and
significantly reduced consumer costs.
HATCI also noted that the requirements that the agency has proposed
would require significant interior redesign which would require longer
design lead time. HATCI encouraged the agency to further harmonize with
established international regulations and rating programs, allow for
more flexible telltale design, and extend the effective dates.
GM, NSC, SRN, Hyundai, HATCI, and an individual commenter also
supported the inclusion of seat belt reminder ratings in NCAP. Hyundai
recommended that NHTSA coordinate its FMVSS and NCAP initiatives to
pursue maximum safety benefits in the shortest feasible timeframes; by
virtue of being voluntary, NCAP enables vehicle safety technology to be
socialized in a non-compulsory way to enhance consumer acceptance.
Hyundai suggested that a follow-on NCAP action might incentivize some
form of a so-called ``Seat Belt Assurance System'' (e.g., limiting
infotainment functionality or constraining vehicle speed when an
occupant is unbuckled) to further motivate buckling up. Hyundai stated
that this suggested NCAP update could also specify requirements
regarding bypassing/disablement to obtain credit for the specified Seat
Belt Assurance System. Hyundai argued that a timely progression of
FMVSS and NCAP actions by NHTSA could appreciably improve seat belt use
rates and consumer acceptance of these vehicle interventions. SRN
commented that if NHTSA did not require the full-status rear seat
warning system, it could reward vehicles with these more effective
systems with NCAP points.
Consumer Reports agreed with NHTSA's decision not to pursue either
of the non-regulatory alternatives presented in the ANPRM.
Agency Response
Because NHTSA is amending FMVSS No. 208 to include these new
requirements, it is not necessary to incorporate these requirements
into NCAP. To help consumers make purchasing decisions, NHTSA currently
indicates on a vehicle's NCAP safety rating web page if the vehicle has
a seat belt reminder system for the front and/or rear passengers. NHTSA
may at a later date, as suggested by some commenters, consider using
NCAP to incentivize enhanced rear seat belt reminder systems. NHTSA
also concurs with Consumer Reports not to pursue either of the non-
regulatory alternatives presented in the ANPRM.
In developing the requirements in this final rule, NHTSA considered
the requirements in ECE R16, as well as materials published by Euro
NCAP and IIHS. NHTSA agrees with the commenters that harmonization is
an important goal and agrees that in some specific instances that the
proposal should be modified to align more closely with ECE R16, Euro
NCAP, and IIHS.
Executive Order 13609 provides that international regulatory
cooperation can reduce, eliminate, or prevent unnecessary differences
in regulatory requirements. Similarly, the Infrastructure, Investment,
and Jobs Act directs that ``[t]he Secretary [of Transportation] shall
cooperate, to the maximum extent practicable, with foreign governments,
nongovernmental stakeholder groups, the motor vehicle industry, and
consumer groups with respect to global harmonization of vehicle
regulations as a means for improving motor vehicle safety.'' \201\
(These directives are also discussed in the Regulatory Analyses
section.) At the same time, the Safety Act authorizes NHTSA to
establish motor vehicle safety standards that, among other things, meet
the need for safety and are practicable.
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\201\ H.R. 3684 (117th Congress) (2021) section 24211.
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Consistent with these directives, and after NHTSA has carefully
considered the comments, the final rule more closely aligns with those
regulatory alternatives where warranted but continues to deviate from
them where necessary. The preceding sections of this document discuss
in detail the ways in which the final rule follows and differs from
these regulatory alternatives and explains why we believe the
[[Page 443]]
departures are justified. The major provisions in the final rule and
the regulatory alternatives, including the differences between them,
are summarized in table 10.
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\202\ The final rule makes no distinction between start-of-trip
and change-of-status visual warnings. It has been combined into one
single visual warning requirement, so the triggering and duration
characteristics summarized here are for the single visual warning
requirement.
Table 10--Comparison of Final Rule With Regulatory Alternatives
----------------------------------------------------------------------------------------------------------------
Topic Final rule UN ECE R16 Euro NCAP IIHS
----------------------------------------------------------------------------------------------------------------
Rear Seat Belt Warning Requirements
----------------------------------------------------------------------------------------------------------------
Applicability................... Excludes small Excludes all small Excludes N/A.
school buses, law buses and more commercial
enforcement categories of vehicles and most
vehicles, and special-purpose vehicles over
ambulances. vehicles. 3,500 kg.
Occupant detection.............. Not required...... Not required...... Awards points only Not required.
for systems with
occupant
detection.
Visual Warning on vehicle
startup:
Type of information conveyed How many or which Indicates at least Indicates the rear Whether the seat
by visual signal. seat belts are in all rear seats to seat belts in use belt at each rear
use and/or not in allow the driver and not in use. seating position
use. to identify any is in use or not
seat where the in use.
belt is not in
use.
Triggering Conditions....... Ignition switch on/ Master control Ignition switch is Engine/motor on;
start or (for switch activated. engaged (engine allows 10-second
EVs) propulsion running or not). delay.
activation.
Seat Occupancy Criteria..... 6-year-old........ 5th percentile 5th percentile Seated human or
female. female. dummy in front
passenger seat
and human in rear
seat (unspecified
size).
Duration.................... 60 seconds........ 60 seconds........ 60 seconds........ 60 seconds.
Audio-Visual Change-of-status
warning:
Duration.................... 30 seconds........ 30 seconds........ 60 second visual 30 seconds.
warning; 30
second audible
warning.
Triggering Conditions....... Fastened belt Fastened belt Fastened belt Fastened belt
becomes becomes becomes becomes
unfastened, the unfastened and unfastened, unfastened,
vehicle is in certain distance, certain distance, certain distance,
forward or time and/or speed time and/or speed time and speed
reverse, and all threshold(s) are threshold(s) are threshold(s) are
rear doors remain exceeded. exceeded, and all exceeded, and all
closed. rear doors remain rear doors remain
closed. closed.
----------------------------------------------------------------------------------------------------------------
Front Seat Belt Warning Requirements
----------------------------------------------------------------------------------------------------------------
Applicability................... Excludes all heavy Does not exclude N/A............... N/A.
vehicles. heavy vehicles
used for carrying
goods.
Front Seating Positions......... Front outboard All positions in All front row Front outboard.
passenger and the same row as positions.
driver (not the driver.
center seat).
Visual Warning--start-of-trip:
\202\
Triggering Conditions....... Seat occupied, Belt unfastened, Belt unfastened, Concurrent with
belt unfastened, ignition or ignition switch audible.
ignition on/start master control engaged.
or (for EVs) switch engaged.
propulsion
activation.
Duration.................... Until belt is 30 seconds........ Until belt is Concurrent with
fastened. fastened. audible.
Visual Warning--Change-of-
Status:
Triggering Conditions....... Seat occupied, If belt remains Belt unfastened, Concurrent with
belt unfastened, unfastened and speed over 25 km/ audible.
ignition on/start certain distance, h (15.5 mph).
or (for EVs) time, and/or
propulsion speed threshold
activation. (25 km/h (15.5
mph)) are
exceeded.
Duration.................... Until belt is At least 30 Until belt is Concurrent with
Fastened. seconds not fastened. audible.
counting gaps
over 3 seconds.
Audible Warning--First Phase:
Triggering Conditions....... Seat occupied, If belt remains Must be deployed Seat occupied,
belt unfastened, unfastened and before and belt unfastened
ignition on/start certain distance, certain distance, at ignition,
or (for EVs) time, and/or time, and/or continuous
propulsion speed threshold speed threshold forward motion of
activation. (25 km/h (15.5 (25 km/h (15.5 at least 10 km/h
mph)) are mph)) are (6.2 mph).
exceeded. exceeded
(``final'' signal
if other, higher
thresholds are
met).
Duration.................... 30 seconds........ At least 30 May not exceed 30 90 seconds.
seconds. seconds
(``final'' signal
at least 90
seconds).
Audible Warning--Second Phase:
Triggering Conditions....... Seat occupied, Fastened belt Fastened belt Occupied seat,
belt unfastened, becomes becomes belt unfastened,
and a speed >=10 unfastened and unfastened, continuous
km/h (6.2 mph). certain distance, vehicle speed forward motion of
time and/or speed over 25 km/h at least 10 km/h
threshold(s) (25 (15.5 mph) (6.2 mph).
km/h (15.5 mph)) (``final audible
are exceeded. signal'' if over
40 km/h (24.9
mph)).
Duration.................... Until belt is At least 30 At least 90 90 seconds.
fastened or speed seconds. seconds.
<10 km/h.
[[Page 444]]
Visual Warning Characteristics.. Must provide Specifies image N/A............... Indicate an
telltale identical to outboard front-
specified in FMVSS No. 101, row seating
FMVSS No. 101, Table 2. position with an
Table 2, the seat unfastened belt.
to which the
telltale is
associated must
be clearly
identified.
----------------------------------------------------------------------------------------------------------------
Other Requirements
----------------------------------------------------------------------------------------------------------------
Audible Warning Characteristics:
Cycle, Chime Frequency, Front First Phase Gap limitations... Gap limitations... Gap limitations.
Signal Gaps. and Rear: Gap
limitations.
Front Second
Phase: Specifies
duty cycle,
warning cycle,
and chime
frequency. No gap
limitations.
Volume...................... No volume ``easily Final audible Must be between 20
requirement. recognizable by warning must be and 20,000 Hz and
the driver''. ``loud and must include at
clear''. least one
dominant
frequency between
500 and 2,250 Hz.
Warning Deactivation, Not permitted..... Short and long- Acknowledgement Rear visual signal
Acknowledgement, and Dismissal. term deactivation allowed for rear may be cancelled
of the audible seats but not for by the driver.
warning with the change-of-
limitations, status warning.
including that it
must be more
difficult to
effectuate a
short-term
deactivation than
to buckle the
belt.
----------------------------------------------------------------------------------------------------------------
VIII. Overview of Benefits and Costs
NHTSA has prepared a Final Regulatory Impact Analysis (FRIA) that
assesses the benefits, costs, and other impacts of this final
rule.\203\ For a more detailed discussion, please refer to the FRIA.
The following sections present the benefits and costs of the final rule
requirements for the rear and front SBWSs and the three major
regulatory alternatives considered. It is important to note that the
incremental benefits presented in the section stem not from the SBWS's
function itself, but instead result from the increase in seat belt use
brought about by the SBWS. Therefore, the incremental benefits
associated with the final rule are comprised of the fatalities and non-
fatal injuries prevented as a result of the increase in seat belt use
from the SBWS.
---------------------------------------------------------------------------
\203\ The FRIA is available in the docket for this final rule
and may be obtained by downloading it or by contacting Docket
Management at the address or telephone number provided in the
ADDRESSES section of this document.
---------------------------------------------------------------------------
A. Final Rule Requirements
NHTSA quantified the benefits and costs of the final rule
requirements. This section presents a summary of the benefits and costs
for the requirements on rear seat belt warning systems, front outboard
seat belt warning systems, and the combined costs and benefits for both
warning systems.
1. Rear Seat Belt Warning System
The September 2023 NPRM sought comment on the potential
effectiveness, benefits, and costs of a rear seat belt warning.
Comments
1. Safety benefits for rear SBWS are underestimated: Consumer
Reports commented in support of the proposed rule stating that the
preliminary regulatory impact analysis (PRIA) likely underestimates the
safety benefits associated with the requirements for the rear seats.
Consumer Reports commented that the analysis did not factor in the
technological advancements of current vehicle fleets which will likely
increase the rate of injury for unrestrained rear seat passengers. More
specifically, Consumer Reports noted that crash avoidance systems that
are associated with hard braking and pre-crash maneuvers may result in
an increased rate of injury to unrestrained rear seat passengers.
Agency Response
Regarding Consumer Reports' comment on underestimating the benefits
associated with rear SBWS, NHTSA has updated the target population in
the final rule using the most recently available data along with
adjustments to account for safety impacts of new required safety
technologies that have yet to be applied to the fleet. These updates in
the final rule correctly reflect the benefits for rear SBWS. This
analysis does not project changes in ridership between front and rear
seat occupants as such projections would introduce uncertainty into the
analysis. However, if ride sharing services increase rear seat
occupancy, it is possible that benefits for rear seat occupants could
be greater than those estimated in this FRIA.
2. Require occupant detection for rear seats: Commentors including
Consumer Reports and NSC urged NHTSA to require SBWS with occupant
detection for rear seats. These commenters also requested that the
agency estimate benefits of the case that manufacturers would choose to
implement negative-only or full-status warning system stating that the
projected increases in seat belt use from the rule would likely be
greater if NHTSA required the full-status compliance option for all
applicable vehicles. Consumer Reports, citing findings of an IIHS
study,\204\ noted that benefits for rear seat occupants may be
underestimated as NHTSA did not account for increases in rear seat
passengers resulting from consumers increasingly using ride sharing
services in recent years.
---------------------------------------------------------------------------
\204\ Kidd and O'Malley titled ``Increasing seat belt use in the
United States by promoting and requiring more effective seat belt
reminder systems.'' https://pubmed.ncbi.nlm.nih.gov/37267012/
#:~:text=If%20every%20vehicle%20in%20the,85.9%25%20in%20the%20rear%20
row.
---------------------------------------------------------------------------
Agency Response
The final rule does not require occupant detection for the rear
SBWS but permits it. Based on comments received, the final rule differs
from the proposed rear SBWS requirements by permitting positive-only,
negative-only,
[[Page 445]]
and full-status SBWS without the use of occupant detection. We believe
that while the full-status system (with occupant detection) does
provide the driver with the most information, as we explained in the
NPRM, we continue to believe that the other allowable types of systems
without occupant detection would provide the driver with sufficient
information to easily determine whether and where there are any
unbuckled occupants and request that they fasten their seat belts.
Although some vehicle manufacturers may implement warning systems with
occupant detection, NHTSA estimated benefits based on vehicle
manufacturers meeting the minimum requirements. Therefore, NHTSA
estimated the incremental benefits and costs associated with the least
costly compliance option, which is a rear SBWS without occupant
detection.
The study by Kidd and O'Malley, cited by Consumer Reports, compares
the effectiveness of SBWS with different warning durations and system
interlocks in increasing seat belt use. The study found that enhanced
reminders, in particular more persistent reminders, are more effective
in increasing seat belt use. Although system interlocks are effective
in increasing seat belt use, they are found to be much less acceptable
than audible reminders and more likely to be circumvented. The 2019
IIHS study by Kidd (used in the PRIA and in this final rule) found that
moving from a 7-second warning to either a 90-second or indefinite
duration warning increased seat belt use for part-time users by 30
percent and 34 percent respectively. Overall, these studies provide
evidence that the relative annoyance or duration of a warning increases
the effectiveness of a SBWS. However, they do not provide any data that
can be used to estimate the increase in seat belt use generated by
adding occupant detection to the rear seat SBWS.
Due to a lack of data, NHTSA is unable to estimate the increase in
seat belt use for a SBWS with occupant detection compared with a SBWS
without occupant detection. Therefore, the agency is unable to estimate
incremental benefits for the regulatory alternative with occupant
detection. Instead, NHTSA considered how much more effective a SBWS
with occupant detection would need to be to generate the same net
benefits as the final rule, which allows for a SBWS without occupant
detection in the rear seat. Overall, a SBWS with occupant detection
would need to increase seat belt use by approximately two to three
times that of a SBWS without occupant detection to generate the same
level of net benefits. As it is not likely that a SBWS would be two or
three times as effective as one without occupant detection, this
regulatory alternative was not selected. However, while occupant
detection was not included as a requirement in the final rule, the
finalized requirements do allow systems that have occupant detection.
3. Cost burden for requiring SBWS on rear seats for high occupancy
vehicles: Mercedes-Benz AG commented on the cost burden of implementing
SBWS for rear seats in high occupancy vans. The commenter noted that
for each removeable seat, an electronic control unit (ECU) would be
required along with other hardware components and corresponding
software. Additionally, one commenter indicated concern that the agency
did not fully account for the potential burden on industry; in
particular, in cases in which businesses will incur the cost of adding
SBWS to vehicles with a large number of rear seats, such as vans and
buses.
Agency Response
In estimating the costs associated with the final rule, the agency
made use of end-user costs estimates from a teardown study. Those unit
costs were then applied on a per-seat basis to the average number of
seats per vehicle and average number of new light vehicles sold
annually to estimate the total annual cost. NHTSA did not estimate
costs on a per-manufacturer or per-business basis but instead provided
the total annual cost to end users. This estimate reflects not only the
cost of materials and labor incurred by manufacturers, but also non-
production costs and profit reflected in the price passed down to
consumers. Additionally, while the per-vehicle cost may vary based on
the number of seats per vehicle, in vehicles with more rear seats, both
costs and benefits will increase. While costs increase based on the
number of seats in a vehicle, benefits increase not only based on both
the number of restrained occupants that avoid injury due to their use
of seat belts, but also due to the reduction in potential injuries from
harmful interactions between unrestrained occupants.
4. Lack of harmonization with existing standards increases cost:
Commenters, including Auto Innovators and Tesla, encouraged harmonizing
with other regulatory and safety ratings requirements. More
specifically, Auto Innovators stated that the agency should consider
potential costs associated with redesign due to misalignment with ECE
R16.
Agency Response: Throughout this final rule NHTSA has considered
harmonization and has taken care to incorporate performance
requirements and test procedures that can, in many cases, enable
systems to also meet ECE R16 requirements to minimize testing and
compliance costs for manufacturers. However, NHTSA declines to fully
harmonize with the test procedures in ECE R16 Annex 18. Since NHTSA's
regulations follow a self-certification approach, it is important to
include certain information in the FMVSS test procedures to ensure that
they are objective and properly test for compliance with this final
rule, which may not be necessary for ECE R16 testing.
In general, the rear seat belt warning system requirements in this
final rule are consistent with those in ECE R16 and Euro NCAP. One
major difference is that ECE R16 evaluates occupant detection using the
5th percentile female dummy while the final rule specifies using a 50th
percentile 6-year-old child or equivalent. For the reasons explained in
a previous section, this final rule addresses a MAP-21 mandate and
requires, if an occupant detection system is provided, that the system
be able to detect children in the rear seats. The weight of a 5th
percentile female dummy is greater than that of many children aged 6 to
16 years old and so it is not an appropriate surrogate for evaluating
child occupancy.
Summary of Analysis and Results
Based on the Fatality Analysis Reporting System (FARS) and the
Crash Investigation Sampling System (CISS) data from 2017 through
2021,\205\ on average 930 unrestrained rear seat occupants were killed
in crashes and 15,380 were injured annually.\206\ After adjusting these
to account for future decreases in fatalities and injuries projected to
occur in the absence of the finalized requirements due to the
introduction of other mandatory safety technologies (e.g., electronic
stability control), the analysis estimates a baseline of, on average,
822 fatalities and 11,409 injuries to unrestrained rear seat occupants
each year.\207\ This is the overall target population for rear seat
occupants--the annual deaths and
[[Page 446]]
injuries that the final rule requirements are aimed at reducing.
---------------------------------------------------------------------------
\205\ The target population in the PRIA reflected the 2011-2015
FARS and 2011-2015 NASS/CDS data. The FRIA updated the target
population to reflect more recent data. The NASS/CDS data previously
used did not reflect injury data for vehicles older than ten years
which may have underestimated injuries.
\206\ See FRIA, appendix A.7.
\207\ See FRIA, tables 25 and 26.
---------------------------------------------------------------------------
We estimated the benefits resulting from the final rule rear seat
belt warning requirements. The benefits are the fatalities and injuries
that we estimate would be prevented by the finalized requirements. The
benefits depend, principally, on the effectiveness of seat belts in
preventing deaths and injuries and the expected increase in seat belt
use due to the finalized rear seat belt warning system requirements.
Seat belt effectiveness in mitigating fatalities for rear seat
occupants 11 years of age and older is 56 percent for passenger cars
and 74 percent for light trucks and vans.\208\
---------------------------------------------------------------------------
\208\ See FRIA, table 33.
---------------------------------------------------------------------------
NHTSA believes that the minimum required warning signal
characteristics would be effective at informing the driver of the use
status of the rear seat belts and facilitating the driver to request
that a rear passenger fasten an unfastened belt. A seat belt warning
system can increase rear seat belt use in two ways: it can remind an
occupant to fasten the occupant's belt, and it can inform the driver
that a passenger is unbuckled, so that the driver can request the
occupant fasten the occupant's belt.\209\ Without a rear seat belt
warning, the driver must turn around to ascertain whether a rear seat
occupant is using a seat belt (or ask the occupant); in some vehicles,
belt use may not be evident to the driver, even if he or she turns
around, due to line-of-sight limitations. As noted above, in NHTSA's
2015 survey, 65 percent of drivers of vehicles equipped with rear seat
belt reminders reported that the rear seat belt reminder made it easier
to encourage the rear seat passengers to buckle up.\210\ Also, as noted
earlier, part-time seat belt users--the predominant non-user group--are
amenable to seat belt warnings. In addition, children, who might be
particularly compliant with driver requests, are proportionally much
more likely to be rear seat passengers than are adults.\211\
---------------------------------------------------------------------------
\209\ Motoyuki Akamatsu et al., Assessment Method of
Effectiveness of Passenger Seat Belt Reminder. 2012-01-0050, SAE
International (2012).
\210\ Survey of Principal Drivers of Vehicles with a Rear Seat
Belt Reminder System at 47.
\211\ Matthew J. Trowbridge & Richard Kent, Rear-Seat Motor
Vehicle Travel in the U.S.: Using National Data to Define a
Population at Risk. Am. J. Prev. Med. 37(4), at 322 (2009).
---------------------------------------------------------------------------
We believe that any of the allowable rear seat belt reminder
systems would be effective at accomplishing this goal. While some
systems provide more information than others, and some would require
the driver to fill in some informational gaps, even the most basic
system (a RSBWS without occupant detection) would inform the driver
about which belts are or are not fastened; the driver would readily be
able to determine whether there were any unbelted occupants. We also
believe that the 60-second visual warning would be effective. NHTSA
could have proposed a more intrusive warning signal, such as an audible
warning and/or a longer-duration visual warning. However, because such
warnings necessitate occupant detection and we are not requiring
occupant detection, we are also not requiring more aggressive warnings.
NHTSA estimated the effectiveness of the rear seat belt warnings.
Available research regarding seat belt use indicates that seat belt
warning systems are effective at increasing seat belt use; however,
estimates of the amount of increased belt usage that can be attributed
to warning systems vary. In arriving at our estimates of increased seat
belt usage from SBWS for rear seats, we examined current seat belt use
rate in rear seats and the results of research conducted by NHTSA and
others on percent increase in seat belt use for different types of
warning systems for front seat occupants, as well as information
submitted in response to the request for comments. For rear seat
passengers 11 years old and older, we used a ``low'' estimate of 3.4
percent increase in seat belt use, and a ``high'' estimate of 5.1
percent increase in seat belt use. For rear seat passengers from six to
ten years old, we used a low estimate of 0.27 percent and a high
estimate of 0.41 percent. (The estimated increases for younger
passengers are much lower because they already have high rates of seat
belt use). For simplicity, we refer to these scenarios as ``Low'' and
``High.'' \212\
---------------------------------------------------------------------------
\212\ See FRIA section 4.2, ``Effect of SBWS on Seat Belt Use
Rates for Rear Seat Occupants.''
---------------------------------------------------------------------------
Based on these belt and warning system effectiveness estimates, we
estimate that the rear seat belt warning requirements would prevent 26
fatalities and 148 injuries annually under the ``Low'' scenario. Under
the ``High'' scenario, we estimate that 39 fatalities and 221 injuries
would be prevented annually.\213\ See table 11. Another way to measure
benefits is by calculating equivalent lives saved. Equivalent lives
saved are the number of prevented fatalities added to the number of
prevented injuries, with the prevented injuries expressed in terms of
equivalent fatalities (that is, with an injury expressed as a fraction
of a fatality, so that the more serious the injury, the higher the
fraction). The estimated equivalent lives saved are presented in table
12 at the 3 percent and 7 percent discount rate.\214\
---------------------------------------------------------------------------
\213\ See FRIA table 47.
\214\ The 3 percent and 7 percent discount rates are in
accordance with OMB Circular A-4. https://www.whitehouse.gov/wp-content/uploads/2023/11/CircularA-4.pdf.
Table 11--Estimated Annual Benefits--Lives Saved and Injuries Prevented
for SBWS Without Occupant Detection (Rear Seats), With Estimated Low and
High Percentage Point Increase in Belt Use
------------------------------------------------------------------------
Injury level Low High
------------------------------------------------------------------------
MAIS 1.................................. 36 54
MAIS 2.................................. 80 120
MAIS 3.................................. 26 38
MAIS 4.................................. 4 6
MAIS 5.................................. 1 2
-------------------------------
Total Injuries...................... 148 221
-------------------------------
Fatal............................... 26 39
------------------------------------------------------------------------
[[Page 447]]
Table 12--Estimated Annual Benefits--Equivalent Lives Saved--SBWS Without Occupant Detection (Rear Seats) \215\
----------------------------------------------------------------------------------------------------------------
3 Percent 7 Percent
Belt use increase Undiscounted discount rate discount rate
----------------------------------------------------------------------------------------------------------------
Low........................................................... 36.22 29.98 24.31
High.......................................................... 54.47 45.09 36.55
----------------------------------------------------------------------------------------------------------------
We also estimated the costs of the finalized requirements. To
comply with the minimum requirements (a positive-only system or
negative-only/full-status system without occupant detection), the
system would need to have seat belt buckle sensors (to determine if the
belt is fastened) and wiring and wire conduits to provide information
on the belt buckle status from the rear seats to the computer processor
controlling the warning system.\216\ Based on the results of NHTSA's
teardown analysis, we estimate a cost of $6.28 per seat. Given an
average of 3.12 rear seats per vehicle, this yields a final cost of
$19.59 per vehicle. Based on this per-vehicle cost, the cost to the
fleet to comply with the finalized minimum requirements is $166.4
million.
---------------------------------------------------------------------------
\215\ See FRIA tables 68 and 70.
\216\ The final rule is based on performance requirements, and
as discussed previously, vehicle manufacturers are not restricted to
using seat belt buckle sensors to determine belt usage. For example,
spool-out sensors could be used instead of seat belt buckle sensors,
but for the purposes of its compliance test NHTSA will consider a
belt to be ``not in use'' when the belt latch is not fastened. We
assume most manufacturers will likely use buckle sensors and that
the cost is the same for seat belt buckle sensors as for spool-out
sensors.
---------------------------------------------------------------------------
Based on the forgoing, we performed benefit-cost and cost-
effectiveness analyses. A benefit-cost analysis calculates net
benefits, which is the difference between the benefits flowing from
injury and fatality reductions and the cost of the rule. Our net
benefit estimates are presented in table 13. The cost-effectiveness
analysis derives the cost per equivalent life saved, which is equal to
the total cost of the rule divided by the total fatal equivalents that
it prevents. These estimates are presented in table 14.
---------------------------------------------------------------------------
\217\ See FRIA table 82.
\218\ See FRIA table 74.
Table 13--Annual Monetized Benefits, Costs, and Net Benefits--SBWS Without Occupant Detection (Rear Seats) \217\
[2020 Dollars, in millions]
--------------------------------------------------------------------------------------------------------------------------------------------------------
3 percent discount rate 7 percent discount rate
Seat belt use increase -----------------------------------------------------------------------------------------------
Benefits Cost Net benefits Benefits Cost Net benefits
--------------------------------------------------------------------------------------------------------------------------------------------------------
Low..................................................... $357.78 $166.44 $191.34 $290.05 $166.44 $123.62
High.................................................... 538.00 166.44 371.56 436.16 166.44 269.72
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 14--Cost-Effectiveness Analysis (Cost per Equivalent Life Saved)--SBWS Without Occupant Detection (Rear
Seats) \218\
[2020 Dollars, in millions]
----------------------------------------------------------------------------------------------------------------
Seat position & belt use increase ELS Cost Cost/ELS
----------------------------------------------------------------------------------------------------------------
3 Percent Discount Rate
----------------------------------------------------------------------------------------------------------------
Low............................................................. 29.98 $166.4 $5.55
High............................................................ 45.09 166.4 3.69
----------------------------------------------------------------------------------------------------------------
7 Percent Discount Rate
----------------------------------------------------------------------------------------------------------------
Low............................................................. 24.31 $166.4 $6.85
High............................................................ 36.55 166.4 4.55
----------------------------------------------------------------------------------------------------------------
2. Front Seat Belt Warning System
Based on FARS and CISS data from 2017 through 2021, on average
8,345 unrestrained drivers and 1,447 unrestrained front outboard
passengers of passenger cars and light trucks were killed annually in
traffic crashes. Additionally, 132,416 unrestrained drivers and 25,046
unrestrained front outboard passengers were, on average, injured
annually. After adjusting these to account for future decreases in
fatalities and injuries projected to occur in the absence of the
finalized requirements due to the introduction of other mandatory
safety technologies (e.g., electronic stability control), the analysis
estimates a baseline of, on average, 8,383 fatalities and 150,739
injuries to unrestrained front seat occupants each year. This is the
overall target population--the annual deaths and injuries that the
final requirements are aimed at reducing.
According to the NOPUS, 90.6 percent of drivers used their seat
belt in 2021, and 89.4 percent of passengers in the right-front seating
position used their seat belt.\219\ To estimate the percentage of
drivers and front passengers who do not always use a seat belt, we used
the results from a 2004 analysis using data from the Household
[[Page 448]]
Component of the 2002 Medical Expenditure Panel Survey (MEPS-HC) \220\
that found that among persons 16-64 years of age, 87.7 percent reported
always or nearly always using seat belts when driving or riding in a
car. Another 6.9 percent reported sometimes using seat belts, while 5.4
percent reported seldom or never using seat belts when driving or
riding in a car. These results are summarized in table 15. This means,
when an observation is made about the percentage of drivers who use the
seat belts, the observed belt use rate is higher than 87.7 percent
since the other groups would contribute to the observed belt use rate
although they are not always using the seat belts. NHTSA recognizes
that driving habits may or may not have changed since 2002 as seat belt
use rates have increased and as new generations of drivers and
passengers are on the road. NHTSA considered, but tentatively decided
not to use, the results of more recent studies, such as the (2016)
Motor Vehicle Occupant Safety Survey (MVOSS) \221\ to estimate the
percentage of drivers and front passengers who do not always use a seat
belt. While the 2016 MVOSS is more recent, we decided to use the 2004
study because we tentatively concluded that the data provided by the
2004 study best suited the needs of our analysis. Although most data on
seat belt use is self-reported, including the data in the 2004 study,
the 2004 study has a high sample size (approximately 25,000) \222\ and
provides robust categorizations of seat belt use that fit the needs of
our analysis. Furthermore, when comparing this data to the findings of
the 2016 MVOSS, we did not find evidence that seat belt use trends have
significantly changed over time.\223\
---------------------------------------------------------------------------
\219\ National Center for Statistics and Analysis. (2021,
December). Seat belt use in 2021--Overall results (Traffic Safety
Facts Research Note. Report No. DOT HS 813 241). National Highway
Traffic Safety Administration.
\220\ May Chu, ``Statistical brief #62: Characteristics of
Persons Who Seldom or Never Wear Seat Belts 2002.'' https://meps.ahrq.gov/data_files/publications/st62/stat62.pdf.
\221\ Spado, D., Schaad, A., & Block, A. (2019, December). 2016
motor vehicle occupant safety survey; Volume 2: Seat belt report
(Report No. DOT HS 812 727). National Highway Traffic Safety
Administration.
\222\ Compared to the 2016 MVOSS, which had, depending on the
question, sample sizes of approximately 5,000 to 10,000.
\223\ For example, the 2016 MVOSS found that about 6 percent of
drivers reported using their belt most of the time or some of the
time. See pg. 7 (Fig. 5) in the MVOSS.
Table 15--Seat Belt Use Characteristics
------------------------------------------------------------------------
Belt user and related items Rate (percent)
------------------------------------------------------------------------
Reported ``sometimes using seat belts''................. 6.9
Reported ``seldom or never using seat belts when driving 5.4
or riding in a car''...................................
Reported always use seat belts.......................... 87.7
---------------
Total............................................... 100.0
------------------------------------------------------------------------
As we did for the rear seats, NHTSA estimated the effectiveness and
benefits associated with requiring a seat belt warning system that
remains activated until the seat belts are buckled for the driver and
front outboard passenger seats. In developing this estimate, NHTSA used
the results of a 2019 study conducted by IIHS by Kidd et al.\224\ In
the Kidd et al. (2019) study, part-time belt users (who had a recent
seat belt citation and reported not always using a seat belt) drove two
vehicles for a certain period of time, a Chevrolet with three
intermittent 7-second audible warnings followed by either a BMW with a
100-second audible warning (n=17) or a Subaru with an audible warning
that continues until the seat belt is buckled (n=16). (All of the
vehicles provided a visual warning that lasted until the seat belt was
buckled.) Kidd et al. found that, relative to the intermittent reminder
(i.e., 7-second audible reminder), the BMW warning with the 100-second
audible reminder increased seat belt use by 30 percent and the Subaru
warning with the indefinite audible warning increased belt use by 34
percent.\225\ The Kidd Study also found that some participants
circumvented the enhanced warning systems by misusing the seat belt
(sitting on a buckled seat belt or routing the buckled seat belt behind
their back). Hard core ``never users'' of seat belts may similarly
choose to circumvent the enhanced seat belt warning system. Therefore,
NHTSA assumed that the ``never and seldom users'' of seat belts (5.4
percent from the Chu study) could potentially circumvent the enhanced
SBWS, so the analysis conservatively assumes no increase in seat belt
use with enhanced SBWS for ``never and seldom users.''
---------------------------------------------------------------------------
\224\ Kidd, D.G., and Singer, J. (2019, April) The effects of
persistent audible seat belt reminders and a speed-limiting
interlock on the seat belt use of drivers who do not always use a
seat belt. Insurance Institute for Highway Safety, Westat, Inc.
\225\ There were several limitations in this study, the main one
being that the number of study participants was small, and,
consequently, there was limited statistical power when comparing the
change in rate of belt use between the different vehicle technology
conditions. The study further discusses this and other limitations,
such as how the demographics of the study sample differ from part-
time belt users nationwide. See also the discussion supra, Section
VI.B.3.
---------------------------------------------------------------------------
NHTSA also reviewed manufacturer data for MY 2020 vehicles to
determine the market penetration of seat belt warning systems of
various durations in the front outboard seats and obtained the
estimates in table 16.
Table 16--Market Penetration of Different Duration Seat Belt Audible
Warning Systems
------------------------------------------------------------------------
Percentage of
SBWS system sales
------------------------------------------------------------------------
<90 second warning...................................... 7.6
90 second and 90+ but not indefinite.................... 85.2
Enhanced--Warning until seat belt is buckled............ 7.2
------------------------------------------------------------------------
[[Page 449]]
For drivers, seat belts reduce the risk of fatality by 48 percent
(for passenger cars) and 61 percent (for light trucks and vans) and
reduce the risk of moderate to greater severity injuries by up to 65
percent.\226\ For front outboard passengers, seat belts reduce the risk
of fatality by 37 percent (for passenger cars) and by 58 percent (for
light trucks and vans) and reduce the risk of moderate to greater
severity injuries by 65 percent.\227\
---------------------------------------------------------------------------
\226\ See FRIA table 31.
\227\ See FRIA table 32.
---------------------------------------------------------------------------
Based on the estimated seat belt warning system effectiveness in
increasing seat belt use, the market penetration of different duration
seat belt audible warning systems, and the effectiveness of seat belts
in mitigating fatalities and injuries, NHTSA estimates that requiring
an audio-visual seat belt warning \228\ that remains activated until
the seat belt is buckled (indefinite duration) would prevent 20 driver
fatalities, 2 front outboard passenger fatalities, and a total of 395
injuries annually, as shown in table 17. This rule results in 46.7
undiscounted equivalent lives saved, as shown in table 18. The
estimated discounted annual benefits in terms of equivalent lives saved
are also shown in table 18.
---------------------------------------------------------------------------
\228\ The final rule differs from the proposed indefinite audio-
visual warning on vehicle start-up, because while the visual warning
will be indefinite it is no longer specific to the ``start-of-trip''
and the audible warning will only be required to activate for at
least 30 seconds and after the 30 seconds it will be a speed-
initiated indefinite audible warning. However, in the benefits and
costs sections we will continue to refer to the front seat belt
warning system as an indefinite warning because both the audible and
visual warnings will be required to be active until the seat belt is
fastened, if the respective trigger criteria are met.
\229\ See FRIA table 60.
\230\ See FRIA table 73.
Table 17--Estimated Annual Benefits--Lives Saved and Injuries Prevented--Indefinite SBWS (Front Outboard Seats)
\229\
----------------------------------------------------------------------------------------------------------------
Injury level Driver Front passenger Total
----------------------------------------------------------------------------------------------------------------
MAIS 1....................................................... 129 14 143
MAIS 2....................................................... 151 19 170
MAIS 3....................................................... 62 8 69
MAIS 4....................................................... 9 1 10
MAIS 5....................................................... 3 0 3
--------------------------------------------------
Total Injuries........................................... 354 42 395
----------------------------------------------------------------------------------------------------------------
Fatal........................................................ 20 2 22
----------------------------------------------------------------------------------------------------------------
Note: Values may not sum due to rounding.
Table 18--Estimated Annual Benefits--Equivalent Lives Saved--Indefinite SBWS (Front Outboard Seats) \230\
----------------------------------------------------------------------------------------------------------------
3 Percent 7 Percent
Undiscounted discount rate discount rate
----------------------------------------------------------------------------------------------------------------
Driver.......................................................... 42.26 34.98 28.36
Front Passenger................................................. 4.44 3.68 2.99
-----------------------------------------------
Total....................................................... 46.70 38.66 31.35
----------------------------------------------------------------------------------------------------------------
We also estimated the costs of the finalized requirements. Since
all driver seats are already required to have at least the basic
warning system, the incremental cost of enhanced seat belt warning for
the driver seat is zero. We assume there would be some labor costs
associated with software updates needed to extend the warning. However,
as this is a simple programming change, this cost would be amortized
over each vehicle's production and is therefore considered de minimis.
Though there are no current requirements for a seat belt warning system
for the front outboard passenger seat, NHTSA estimates that 96 percent
of vehicles have seat belt warning systems on the front outboard
passenger seat. NHTSA estimated the cost of equipping a seat belt
warning system in the front outboard passenger seat to be $2.13 per
seat. Therefore, the cost of equipping the remaining 4 percent of the
16 million new vehicle fleet is $1.36 million (= 16 million x 4 percent
x $2.13).
Based on the foregoing, we performed benefit-cost and cost-
effectiveness analyses. The estimated net benefits, based on a 3
percent and 7 percent discount, are presented in table 19 and the cost-
effectiveness estimates are presented in table 20.
---------------------------------------------------------------------------
\231\ See FRIA, tables 80, 81, and 82.
Table 19--Annual Monetized Benefits, Costs and Net Benefits--Indefinite SBWS (Front Outboard Seats) \231\
[2020 Dollars, in millions]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Driver Front passenger Driver and front passenger
-----------------------------------------------------------------------------------------------
3 Percent 7 Percent 3 Percent 7 Percent 3 Percent 7 Percent
--------------------------------------------------------------------------------------------------------------------------------------------------------
Passenger car Benefits.................................. $188.89 $154.12 $22.86 $18.65 $211.75 $172.77
Light Truck & Van Benefits.............................. 228.51 184.29 21.05 16.97 249.56 201.26
-----------------------------------------------------------------------------------------------
[[Page 450]]
Total Benefits...................................... 417.41 338.41 43.90 35.62 461.31 374.03
Total Costs......................................... 0 0 1.36 1.36 1.36 1.36
--------------------------------------------------------------------------------------------------------------------------------------------------------
Net Benefits............................................ 417.41 338.41 42.54 34.26 459.95 372.67
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 20--Cost-Effectiveness Analysis (Cost per Equivalent Life Saved)--Indefinite SBWS (Front Outboard Seats)
\232\
[2020 Dollars, in millions]
----------------------------------------------------------------------------------------------------------------
Discount rate ELS Cost Cost/ELS
----------------------------------------------------------------------------------------------------------------
3 percent....................................................... 38.66 $1.36 $0.04
7 percent....................................................... 31.35 $1.36 $0.04
----------------------------------------------------------------------------------------------------------------
3. Overall Benefits and Costs of the Final Rule
---------------------------------------------------------------------------
\232\ See FRIA, table 74.
---------------------------------------------------------------------------
In table 21, we combine the benefits and costs for the finalized
rear and front seat belt warning requirements. We estimate positive net
benefits under all discount rates and effectiveness estimates.
Table 21--Net Benefits From the Final Rule (SBWS for Rear Seating
Positions and Indefinite SBWS for Front Outboard Seating Positions)
[2020 Dollars, in millions] \233\
------------------------------------------------------------------------
3 Percent 7 Percent
discount rate discount rate
------------------------------------------------------------------------
Front Outboard Seats.................... $459.95 $372.67
Rear Seats.............................. 191.34 123.62
(low increase in rear seat belt use)....
Rear Seats.............................. 371.56 269.72
(high increase in rear seat belt use)...
-------------------------------
Total Net Benefits.................. 651.29 496.28
(low increase in rear belt use).....
Total Net Benefits.................. 831.51 642.39
(high increase in rear belt use)....
------------------------------------------------------------------------
In table 22, we combine the equivalent lives saved and cost for the
finalized rear and front seat belt warning requirements to determine
the cost per equivalent life saved.
---------------------------------------------------------------------------
\233\ See FRIA, table 82.
\234\ See FRIA, table 74.
Table 22--Cost per Equivalent Lives Saved from the Final Rule (SBWS for Rear Seating Positions and Indefinite SBWS for Front Outboard Seating Positions)
\234\
[2020 Dollars, in millions]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Discounted at 3 percent Discounted at 7 percent
--------------------------------------------------------------------------------------
Category Cost per Cost per
Equivalent Cost Equivalent Equivalent Cost Equivalent
Lives Saved Live Saved Lives Saved Live Saved
--------------------------------------------------------------------------------------------------------------------------------------------------------
Rear Seat:
Low.......................................................... 29.98 $166.44 $5.55 24.31 $166.44 $6.85
High......................................................... 45.09 3.69 36.55 4.55
Front Seat....................................................... 38.66 1.36 0.04 31.35 1.36 0.04
--------------------------------------------------------------------------------------
Total:.......................................................
Low...................................................... 68.65 167.8 2.44 55.66 167.8 3.01
High..................................................... 83.75 2.00 67.90 2.47
--------------------------------------------------------------------------------------------------------------------------------------------------------
[[Page 451]]
B. Regulatory Alternatives
In the preceding sections of this document, we discussed various
alternatives for different aspects of the finalized requirements. We
quantified the costs and benefits of three of these alternatives (rear-
seat occupant detection, a 90-second front outboard seat belt warning,
and front center seat belt warning). Below, we briefly summarize our
results. For a more detailed discussion, the reader is referred to the
Final Regulatory Impact Analysis in the docket for this rulemaking.
1. Occupant Detection in Rear Seats
For the rear seat belt reminder, NHTSA is not requiring occupant
detection in the rear seats but permits occupant detection in rear
seats. As a regulatory alternative, NHTSA estimated the costs and
benefits of requiring a SBWS with occupant detection in the rear seats.
NHTSA's teardown analysis indicates that occupant detection
components cost $39.75 per vehicle, which, added to the $19.59 per
vehicle cost of the buckle sensor, results in a combined warning system
cost of $59.33 per vehicle (2020 $). NHTSA estimates that about 47
percent of new vehicles have a SBWS for the rear seating positions and
7 percent of new vehicles have occupant detection in rear seats. If
NHTSA selected the regulatory alternative that required occupant
detection, this rule would result in a total cost of $802 million. As
with the final rule, this cost estimate assumed that 53 percent of new
vehicles would need to install a seat belt sensor in the rear seats.
And as discussed, rear seat occupant detection systems would need to be
installed in all new vehicles. Although seven percent of light vehicles
already have rear seat occupant detection, those SBWSs may not meet the
requirements specified in this regulatory alternative.\235\ As a
result, this analysis accounts for the cost of adding occupant
detection in the rear seats in all new light vehicles to comply with
this regulatory alternative. The total cost for this regulatory
alternative is about $802 million.\236\
---------------------------------------------------------------------------
\235\ The rear seat occupant detection in current vehicles is
likely only able to detect a 5th percentile female and heavier
occupants, but not children who weigh less than the 5th percentile
female as is required for rear seat occupant detection in this final
rule.
\236\ See FRIA, table 119.
---------------------------------------------------------------------------
Because there is uncertainty in how much more effective a SBWS with
occupant detection would be in increasing seat belt use compared to the
already estimated increase in seat belt use with SBWSs without occupant
detection, NHTSA did not conduct a cost-effectiveness and net benefits
analysis. Instead, NHTSA estimated the minimum increase in seat belt
use for this regulatory alternative that would result in overall
benefits equal to the overall costs (zero net benefits). Furthermore,
for a direct comparison to the final rule requirements, NHTSA also
considered how much greater the benefits from this regulatory
alternative would have to be for the net benefits to be equal to those
from the final rule, which does not require occupant detection.
The agency estimated that seat belt use for rear seat occupants 11
years and older would have to increase by approximately 5.4 percent
when discounted at 3 percent and 6.7 percent when discounted at 7
percent for this regulatory alternative to result in zero net benefits.
Moreover, for this regulatory alternative to match the net benefits
(taking into account the Low and High estimates of increased seat belt
usage) from the final rule, seat belt use for rear seat occupants 11
years and older would have to increase by 7.8 to 9.0 percent when
discounted at 3 percent, and by 9.1 to 10.2 percent when discounted at
7 percent.
Under the final rule, which does not require occupant detection,
seat belt use for rear seat occupants 11 years and older is estimated
to increase from 75.12 percent to approximately 76.93 percent in the
Low estimate and 77.84 percent in the High estimate. These increases
reflect an approximately 2.4 percent and 3.6 percent increase in seat
belt use under the final rule.
Therefore, in this regulatory alternative requiring occupant
detection for the rear seats, SBWS for rear seat occupants would need
to be approximately 2.5 to 3.8 times more effective than the final rule
at increasing seal belt usage to generate the same level of net
benefits as the final rule. The SBWSs considered under this regulatory
alternative are capable of informing the driver either which occupants
are not using their seat belts or how many of the rear seat occupants
are not using their seat belts. While we would expect some possible
increase in seat belt use from that specific functionality, it is
doubtful that it would double to quadruple the increase in seat belt
use estimated for SBWSs without occupant detection. Therefore, based on
the available information, the agency did not choose this regulatory
alternative.
2. 90-Second Front Outboard Seat Belt Warning
NHTSA also estimated the costs and benefits if it were to require a
90-second audio-visual warning for the front outboard seats instead of
the finalized requirement for a warning that lasts until the belt and
any occupied seat is buckled. NHTSA estimated the benefits in a similar
manner as that for the finalized seat belt warning for front seat
occupants where the warning remains on until the seat belt is buckled.
The main difference is that this alternative only affects the 7.6
percent of the vehicle fleet with a front seat occupant seat belt
warning with duration less than 90 seconds.
The benefits of this alternative are presented in table 23.\237\
---------------------------------------------------------------------------
\237\ See FRIA, tables 134 and 138.
Table 23--Injuries Prevented, Lives Saved, and Equivalent Lives Saved in Front Outboard Seats by a 90 Second
Duration SBWS
----------------------------------------------------------------------------------------------------------------
Injuries and Fatalities Prevented Equivalent Lives Saved
Injury Level ---------------------------------------------------------------------
Driver Front Passenger Driver Front Passenger
----------------------------------------------------------------------------------------------------------------
MAIS 1.................................... 43 4.7 0.19 0.02
MAIS 2.................................... 44 5.7 1.82 0.23
MAIS 3.................................... 18 2.3 3.26 0.41
MAIS 4.................................... 3 0.3 0.83 0.08
MAIS 5.................................... 1 0.1 0.47 0.05
Fatal..................................... 6 0.6 6.07 0.57
---------------------------------------------------------------------
Total................................. .............. ................. 12.66 1.37
----------------------------------------------------------------------------------------------------------------
[[Page 452]]
About 14 equivalent lives are saved by this alternative, which is
significantly lower than the nearly 47 equivalent lives saved by a
warning that remains on until the seat belt is buckled. The cost of
this alternative is the same as that for the warning required by this
final rule. The only cost is that for the 4 percent of vehicles without
a seat belt warning system in the front outboard passenger seat (cost =
$1.36 million). The annual monetized benefits, costs, and net benefits
of this alternative are shown in table 24.
---------------------------------------------------------------------------
\238\ See FRIA, tables 142 and 143.
Table 24--Annual Monetized Benefits, Costs and Net Benefits for a 90 Second Duration SBWS in Front Outboard
Seats \238\
[2020 Dollars, in millions]
----------------------------------------------------------------------------------------------------------------
Driver Front Passenger Driver and Front
---------------------------------------------------- Passenger
-------------------------
3 Percent 7 Percent 3 Percent 7 Percent 3 Percent 7 Percent
----------------------------------------------------------------------------------------------------------------
Passenger car Benefits............ $58.69 $47.89 $7.25 $5.92 $65.94 $53.81
Light Truck & Van Benefits........ 66.34 53.50 6.25 5.04 72.59 58.54
-----------------------------------------------------------------------------
Total Benefits................ 125.03 101.39 13.50 10.96 138.54 112.35
Total Costs....................... 0 0 1.36 1.36 1.36 1.36
----------------------------------------------------------------------------------------------------------------
Net Benefits.................. 125.03 101.39 12.14 9.59 137.18 110.99
----------------------------------------------------------------------------------------------------------------
While this regulatory alternative has positive net benefits, the
benefits and net benefits are significantly lower than the indefinite
duration SBWS for front seat occupants in the final rule (net benefits
of $459.95 million and $372.67 million when discounted to 3 and 7
percent, respectively).
3. Seat Belt Warning for Front Center Seat
The agency also considered requiring a seat belt warning system for
the front center seating position. To estimate incremental benefits,
NHTSA used the 2017-2021 FARS data and CISS data, and the adjustment
factors to account for safety impacts of new required safety
technologies to establish the target population addressed by this
regulatory alterative (Table 25).
---------------------------------------------------------------------------
\239\ See FRIA, table 122.
Table 25--Annual Adjusted Fatalities and Non-Fatal Injuries to Front Center Seat Passengers \239\
----------------------------------------------------------------------------------------------------------------
Injury severity Restrained Unrestrained Total
----------------------------------------------------------------------------------------------------------------
MAIS 1.......................................................... 190 100 290
MAIS 2.......................................................... 0 0 0
MAIS 3.......................................................... 0 0 0
MAIS 4.......................................................... 0 0 0
MAIS 5.......................................................... 0 0 0
-----------------------------------------------
Total Injuries.............................................. 190 100 290
(MAIS 1-5)..................................................
----------------------------------------------------------------------------------------------------------------
Fatal........................................................... 6 13 19
----------------------------------------------------------------------------------------------------------------
Due to a lack of data, NHTSA is unable to establish the seat belt
use rate for front center passengers under the baseline. As front
center seat passengers are most similar to front outboard passengers,
this analysis makes use of the established seat belt use rate for front
outboard passengers to establish the baseline seat belt use rates for
front center seat occupants. Based on the 2021 NOPUS data, the baseline
seat belt use rate is 89.40 percent and the corresponding seat belt use
rate in potentially fatal crashes is 76.88 percent.
In order to estimate the change in seat belt use for front center
seat passengers as a result of the SBWS, this analysis makes use of the
linear regression model used to estimate the impact of the SBWS on the
seat belt use rates of rear seat occupants. Under this regulatory
alternative, the seat belt use rate for front center seat passengers
using the high estimate is 91.58 percent and the corresponding seat
belt use rate in potentially fatal crashes is 79.69 percent.
The cost for front center passenger seats would include the cost
for a buckle sensor and occupant detection. Therefore, the cost per
vehicle for this regulatory alternative is $14.86 in 2020 dollars. This
cost estimate reflects a cost of $2.13 to add a buckle sensor and the
cost to add occupant detection of $12.73.
In assessing the number of vehicles that would be impacted by this
regulatory alternative, we consider that the front center seat is not a
common feature in new light vehicles. Based on our engineering
judgement, we expect that approximately 800,000 vehicles or 5 percent
of the new vehicle fleet include a center seating position. Table 26
presents the total cost to meet the requirements under this regulatory
alternative for an indefinite duration SBWS for front center passenger
seats.
[[Page 453]]
Table 26--Total Cost of Indefinite Duration SBWS for Front Center Passenger Seats \240\
----------------------------------------------------------------------------------------------------------------
Number of vehicles impacted Per vehicle cost Total cost
----------------------------------------------------------------------------------------------------------------
800,000 $14.86 $11,888,000
----------------------------------------------------------------------------------------------------------------
Table 27 presents the of the cost-effectiveness analysis and table
28 presents the benefit-cost analysis for this regulatory
alternative.\241\ When discounted at three and seven percent, the cost
per ELS is approximately $40.9 million and $50.6 million, respectively
and the net benefits are negative for this regulatory alternative.
Because the cost per ELS is higher than the comprehensive cost of a
fatality and the net benefits are negative, this regulatory alternative
is not cost-effective.
---------------------------------------------------------------------------
\240\ See FRIA, table 128.
\241\ See FRIA, tables 129 and 130.
Table 27--Cost-Effectiveness Analysis for SBWS Front Center Seat Passengers
[Millions]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Discounted at 3 percent Discounted at 7 percent
-----------------------------------------------------------------------------------------------------
Category Cost per Cost per
Equivalent Cost equivalent live Equivalent Cost equivalent live
lives saved saved lives saved saved
--------------------------------------------------------------------------------------------------------------------------------------------------------
Front Center Seat................................. 0.29 $11.89 $40.91 0.23 $11.89 $50.63
--------------------------------------------------------------------------------------------------------------------------------------------------------
Table 28--Benefit-Cost Analysis for SBWS Front Center Seat Passengers
[Millions]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Discounted at 3 percent Discounted at 7 percent
-----------------------------------------------------------------------------------------------------
Category Monetized Monetized
benefits Cost Net benefits benefits Cost Net benefits
--------------------------------------------------------------------------------------------------------------------------------------------------------
Front Center Seat................................. $3.47 $11.89 -$8.42 $2.80 $11.89 -$9.09
--------------------------------------------------------------------------------------------------------------------------------------------------------
IX. Compliance Dates
NHTSA proposed that vehicles be required to comply with the
requirements of this rule the first September 1 that is one year after
the publication of the final rule for the front seat belt warning
system requirements and the first September 1 that is two years after
the publication of the final rule for the rear seat belt warning system
requirements, with optional early compliance permitted. Consistent with
49 CFR 571.8(b), multi-stage manufacturers and alterers would have an
additional year to comply.
We estimated it would take two years for manufacturers to equip
their vehicles with the necessary technologies, redesign hardware and
software components, and validate their systems to comply with the
requirements for the rear seat belt reminder systems. Regarding front
passenger outboard seat belt warning requirements, we noted that
because of the market penetration of such systems (96 percent of new
vehicles), the majority of vehicle manufacturers would simply have to
make software adjustments necessary to ensure they meet the proposed
requirements.\242\
---------------------------------------------------------------------------
\242\ 88 FR 61674. This figure is based on data on total
projected vehicle sales in the United States for MY 2022 from the
agency's New Car Assessment Program Purchasing with Safety in Mind:
What to Look For When Buying a Vehicle program.
---------------------------------------------------------------------------
Comments
The National Transportation Safety Board (NTSB) supported the
proposed lead time and emphasized the timeline of this rulemaking
activity related to seat belt warning systems.
Several commenters suggested shorter lead times. MADD and Advocates
and Public Citizen supported a compliance deadline as soon as is
feasible. MADD stated that given the state and availability of current
technology, a one-year deadline for compliance is likely reasonable.
Advocates and Public Citizen stated that one year should be sufficient
for rear systems, noting that IIHS testing has demonstrated that this
deadline is achievable and that delaying will cost lives.
SRN commented that, depending on the date on which the final rule
is published, the rear seat compliance deadline could be closer to 3
years, and urged NHTSA to ensure that compliance is required within
close to a 2-year window.
IIHS and NAMIC commented that the requirements should be
implemented immediately. IIHS noted research suggesting that increasing
seat belt use of unbuckled occupants throughout the vehicle by up to 34
percent would save about 1,600 lives each year (Kidd & O'Malley, 2023),
and that delaying the implementation of the upgraded standard would
unnecessarily delay its life-saving benefits. IIHS explained that
according to its evaluations, since 2022 adoption of rear reminder
systems has increased and manufacturers have responded quickly in the
past to their requirements, suggesting that less lead time is needed.
Consumer Reports agreed with IIHS that manufacturers have
demonstrated they can make improvements quickly and suggested that both
rear and front reminders be required within 1 year. They also noted
that in 2012, Congress mandated that NHTSA issue a final rule by 2015,
and that the ANPRM for this rulemaking was published in 2019. They
argued that given this timeline, compliance should be required sooner.
Other commenters requested that the compliance dates be extended.
Auto Innovators contended that the proposed lead time is not reasonable
or practical for implementing the proposed changes.
[[Page 454]]
In particular, they emphasized that the lack of harmonization with ECE
R16 may result in design changes for vehicles that are in the final
stages of preproduction and manufacturers may no longer be able to use
hardware and software systems currently deployed in other markets.
Honda provided a list of changes that it would undertake to meet the
requirements proposed in the NPRM and suggested that the lead time
proposed is inadequate to accomplish them.
Nissan also requested additional lead time, especially if it is
necessary to relocate the front outboard passenger telltale. Auto
Innovators and Honda noted that if NHTSA harmonized the rule further
with ECE R16, less lead time would be needed to meet the requirements.
Auto Innovators, HATCI, Ford, and Honda requested a synchronized
two-year phase-in for both the front and rear row seating position
requirements that begins three years after publication of the final
rule. In their proposal, a set percentage of vehicles would be required
to meet the requirements of the rule beginning the first September 1st
that is at least 3 years after publication of the final rule; a higher
percentage by the first September 1st after 4 years; with full
compliance by the first September 1st that is at least five years after
publication of the final rule. HATCI specified that the first phase-in
threshold should be no more than 50 percent of vehicles. Ford and Honda
emphasized that this approach would allow manufacturers to account for
differences in implementation across models with varied development
cycles. Auto Innovators and Honda argued that this approach would unify
the lead time for front and rear systems because there would not be a
benefit to having different lead times for front and rear systems due
to the limitations of production schedules. Auto Innovators commented
that there is no benefit or regulatory relief provided by NHTSA's
proposal for one year of lead time for the front and two years for the
rear because it is both highly impractical and unlikely that
manufacturers will be able to adjust production schedules to account
for changes to the front row and rear row seating positions
independently of each other, and only one year apart. Additionally,
some commenters, such as Auto Innovators and Nissan, commented that if
the rule does not allow for the reminder to be overridden, it will
likely result in the need for significant changes to the instrument
cluster that will require additional time and resources to implement.
Nissan commented that additional lead time becomes more critical if
relocating the front outboard passenger telltale indicator beyond the
vehicle's current meter display is required.
A few commenters, such as Auto Innovators and Consumer reports,
requested that optional early compliance be allowed.
Auto Innovators urged the agency to announce whether the lead time
will be changed through the docket, other such notice, or to publish a
second NPRM within one year of its original filing, to ensure that
manufacturers do not waste time, money, and effort to develop products
that align with the proposal, but which need to be changed to meet the
final rule.
Agency Response
NHTSA is finalizing the compliance dates as proposed in the NPRM.
These dates properly balance the practical realities of bringing
systems into compliance with maximizing the safety benefits of this
rule. We are allowing optional early compliance.
NHTSA disagrees with commenters who argue that compliance can be
required immediately or who seek to shorten the compliance timeline.
NHTSA understands that any allowed time to bring systems into
compliance risks reducing some of the benefits of the rule. However, we
must balance maximizing effectiveness with considerations of
feasibility and practicability. Although commenters correctly point out
that the necessary technologies for both front and rear systems are
available, they underestimate the time some manufacturers may need to
integrate components into vehicles for the rear seat reminder as well
as incorporate visual signals and validate system performance for both
front and rear positions. Although some manufacturers may have been
able to rapidly adapt their systems to changes in IIHS ratings, this
fact does not support the notion that doing so would be practicable for
the entire industry. For example, a small number of vehicles do not yet
have voluntary front passenger seat belt warnings, and these vehicles
would need hardware integration. We also disagree with NAMIC and
Consumer Reports that the duration of this rulemaking effort warrants
shortening the date schedule. Our determination regarding the proper
compliance dates is based on current information and when the rule is
finalized. The option of early compliance may realize earlier safety
benefits for vehicles with earlier development schedules.
NHTSA also disagrees with commenters seeking to extend the dates.
In particular, a three-year compliance date with a two-year phase-in,
suggested by Auto Innovators, HATCI, Honda, and Ford, dramatically
exceeds the amount of time that manufacturers should need to implement
the changes required by this rule. As noted, the technology for these
systems already exists. For front systems in particular, the vast
majority of vehicles already incorporate the necessary technology, and
only software changes will be needed to bring systems into compliance.
Additionally, we have made changes from the NPRM which should
significantly reduce the time needed to bring systems into compliance.
For example, this final rule no longer dictates specific compliance
options for the information conveyed by the rear seat belt warning
visual warning; the finalized requirements for the visual warning allow
all of the systems that would have been allowed under the proposed
rule, as well as additional systems that would not have been allowed
under the proposed rule, such as a negative-only system without
occupant detection and a full-status system without occupant detection.
It also does not require the front passenger seat belt visual warning
to be visible to the front passenger (except for certain ADS-equipped
vehicles), which was an element of the proposal about which certain
commenters, such as Nissan, expressed significant cost and time
concerns. Indeed, in the NPRM we sought comment, and received no
detailed comments, regarding which types of vehicles might need
additional lead time to accommodate the proposed visibility
requirement. Additionally, Auto Innovators noted that less time would
be needed to implement requirements that harmonize with ECE R16. We
have also incorporated changes from the NPRM which increase
harmonization with ECE R16 significantly. Finally, we do not believe it
is necessary to grant additional time to accommodate that warnings are
not allowed to be overridden because this rule provides a large amount
of flexibility for manufacturers to design and locate the visual alerts
to resolve this issue.\243\ Because these elements resolve many of the
concerns raised by
[[Page 455]]
commenters about the compliance timeline, we are not extending the
compliance dates.
---------------------------------------------------------------------------
\243\ While the final rule requires that the visual warning must
not be overridden by other visual warnings, it does allow the
audible warning to be paused during the activation of another
audible safety warning that is designed to alert the driver to take
immediate action; in this case, however, the seat belt audible
warning must be resumed for the remainder of the required duration
after the other audible warning deactivates.
---------------------------------------------------------------------------
We are also not implementing a unified lead time for front and rear
systems. As we pointed out in the NPRM, 96 percent of vehicles already
have a front outboard passenger seat belt warning system, while market
penetration for rear systems is much lower. The acquisition and
integration of additional hardware for rear seats, which is not needed
for the vast majority of front passenger systems, warrants additional
lead time for the rear systems.
Finally, because we are not changing the lead time from the
proposal, we are not publishing the notice of changes regarding the
lead time requested by Auto Innovators.
X. Regulatory Analyses
Executive Order 12866, Executive Order 14094, Executive Order 13563,
and DOT Regulatory Policies and Procedures
NHTSA has considered the impact of this rule under Executive Order
12866, Executive Order 14094, Executive Order 13563, DOT Order 2100.6A,
and the Department of Transportation's regulatory policies and
procedures.\244\ The Office of Management and Budget determined that
this rule is a significant regulatory action and was reviewed under
Section 3(f)(1) of E.O. 12866, as amended by E.O. 14094. Pursuant to
E.O. 12866 and the Department's policies, we have identified the
problem this rule addresses, assessed the benefits and costs, and
considered alternatives. These analyses have been summarized in Section
VII, Regulatory Alternatives and Section VIII, Overview of Benefits and
Costs and are discussed in more detail in the docketed final regulatory
impact analysis.
---------------------------------------------------------------------------
\244\ 49 CFR, Part 5, Subpart B; Department of Transportation
Order 2100.6A, Rulemaking and Guidance Procedures, June 7, 2021.
---------------------------------------------------------------------------
Promoting International Regulatory Cooperation
The policy statement in section 1 of Executive Order 13609 provides
that the regulatory approaches taken by foreign governments may differ
from those taken by the United States to address similar issues, and
that in some cases the differences between them might not be necessary
and might impair the ability of American businesses to export and
compete internationally. It further recognizes that in meeting shared
challenges involving health, safety, and other issues, international
regulatory cooperation can identify approaches that are at least as
protective as those that are or would be adopted in the absence of such
cooperation and can reduce, eliminate, or prevent unnecessary
differences in regulatory requirements.
In addition, section 24211 of the Infrastructure, Investment, and
Jobs Act (IIJA; Pub. L. 117-58), Global Harmonization, provides that
DOT ``shall cooperate, to the maximum extent practicable, with foreign
governments, nongovernmental stakeholder groups, the motor vehicle
industry, and consumer groups with respect to global harmonization of
vehicle regulations as a means for improving motor vehicle safety.''
\245\
---------------------------------------------------------------------------
\245\ H.R. 3684 (117th Congress) (2021).
---------------------------------------------------------------------------
As discussed in Section VII and through this preamble, this rule
harmonizes with ECE R16, Euro NCAP, and the IIHS protocol as much as
possible, but deviates where we believed it was justified with respect
to the Safety Act criteria (need for safety, objectivity, and
practicability). The reasons for following or deviating in any of these
respects are explained in detail in the relevant section of the
preamble. In general, we believe that although this rule deviates from
these requirements or protocols in some ways, it is not incompatible
with them, so that it is possible to design a seat belt reminder system
that complies with both this rule and protocols such as R16. Further,
almost all international NCAP programs, including those in Europe,
Japan, China, Korea, Latin America, Southeast Asia, and Australia and
New Zealand, award points to vehicles that are equipped with seat belt
warning systems for passenger seating positions. Thus, the requirements
in this rule are consistent with these international programs and
complement those international efforts to increase seat belt use by all
vehicle occupants.
Regulatory Flexibility Act
Pursuant to the Regulatory Flexibility Act (5 U.S.C. 601 et seq.,
as amended by the Small Business Regulatory Enforcement Fairness Act
(SBREFA) of 1996), whenever an agency is required to publish an NPRM or
final rule, it must prepare and make available for public comment a
regulatory flexibility analysis (RFA) that describes the effect of the
rule on small entities (i.e., small businesses, small organizations,
and small governmental jurisdictions). The Small Business
Administration's regulations at 13 CFR part 121 define a small
business, in part, as a business entity ``which operates primarily
within the United States.'' 13 CFR 121.105(a). No regulatory
flexibility analysis is required if the head of an agency certifies
that the rule will not have a significant economic impact on a
substantial number of small entities. SBREFA amended the Regulatory
Flexibility Act to require Federal agencies to provide a statement of
the factual basis for certifying that a rule will not have a
significant economic impact on a substantial number of small entities.
I certify that this final rule would not have a significant
economic impact on a substantial number of small entities. According to
13 CFR 121.201, the Small Business Administration's size standards
regulations used to define small business concerns, manufacturers of
the vehicles covered by this final rule would fall under North American
Industry Classification System (NAICS) No. 336211, Automobile
Manufacturing, which has a size standard of 1,000 employees or fewer.
NHTSA estimates that there are three small light vehicle
manufacturers in the U.S. As noted in Section 11.1 of the docketed
final regulatory impact analysis, the estimated annual vehicle sales
for these three manufacturers range from 25 to 100 vehicles with a
sales price range $24,000 to $750,000 and estimated annual revenue
between $2 million and $4 million. We estimate that there are several
hundred second-stage or final-stage manufacturers and alterers that
could be impacted by this final rule. The agency has analyzed the
economic impact on these entities. For the reasons discussed below and
detailed in the final regulatory impact analysis, we conclude that this
rule would not have a significant economic impact on a substantial
number of small entities.
The rule would directly affect motor vehicle manufacturers,
including small light vehicle manufacturers. However, we believe that
the rule will not have a significant economic impact on these entities.
Small manufacturers are already certifying their vehicle's compliance,
for the driver position, with FMVSS No. 208's seat belt warning system
requirements. The means they use to certify to the current requirements
would be similar to or the same as those they would use to certify to
the rear seat belt warning requirements and front outboard passenger
seat belt warning requirements under the final rule.
Further, the compliance test is a relatively simple test, involving
a test technician positioning a person or test dummy in a seat and
checking if the requisite signals activate. Checking to see if visual
and audible warnings activate for the driver seat belt warning
[[Page 456]]
system has been a part of FMVSS No. 208 compliance testing for many
years, and manufacturers are knowledgeable about conducting such tests.
Small manufacturers have options available to certify compliance,
none of which will result in a significant economic impact on these
entities. The manufacturers can and do obtain seating systems from seat
suppliers and install the seats on the body following the instructions
of the seat supplier. Seat and seat belt suppliers are large entities
with resources available to assist small manufacturers in incorporating
the seat belt warning systems, if manufacturers need technical
assistance (which we do not think they will need, given the simplicity
of the systems, particularly those rear systems that do not involve
occupant detection). We do not believe that current manufacturing
practices will have to change significantly because of this rule.
In addition, we also believe that the rule will not have a
significant impact on small and limited-line vehicle manufacturers
because the market for the vehicles produced by these entities is
highly inelastic. Purchasers of these vehicles are attracted by the
desire to have an unusual vehicle. Further, all light vehicles would
have to comply with the requirements. Since the price of complying with
the rule will likely be passed on to the final consumer, the price of
competitor's models would increase by similar amounts. Further, we do
not believe that raising the price of a vehicle to account for the
incremental costs estimated for this final rule ($2.13 for the front
outboard passenger seat and $19.59 for the rear seats) would have much,
if any, effect on vehicle sales.
There are a significant number (several hundred) of second-stage or
final-stage manufacturers and alterers that would be impacted by a
final rule. These manufacturers buy incomplete vehicles to finish as
complete vehicles or modify previously certified vehicles. Many of
these latter vehicles are van conversions; there are a variety of
vehicles affected.
To produce a vehicle, a final-stage manufacturer can either stay
within the incomplete vehicle document (IVD) furnished by the
incomplete vehicle manufacturer (which are typically large vehicle
manufacturers, such as GM or Ford), or the final-stage manufacturer can
work with incomplete vehicle manufacturers to enable the final-stage
manufacturer to certify to the new requirements.\246\ The final-stage
manufacturer can also certify to the standard using due care based on
an assessment of the information available to the manufacturer.
---------------------------------------------------------------------------
\246\ For a discussion of NHTSA's certification regulations for
final stage manufacturers, see 71 FR 28168, May 15, 2006, Docket No.
NHTSA-2006-24664, Response to petitions for reconsideration of a
final rule implementing regulations pertaining to multi-stage
vehicles and to altered vehicles. The Background section of that
document provides concepts and terminology relating to the
certification of multi-stage vehicles.
---------------------------------------------------------------------------
While there are a substantial number of multi-stage manufacturers
that could be impacted by the final rule, we believe that the impact on
them would not be significant. We note that these manufacturers are
already certifying their vehicles to FMVSS No. 208's seat belt warning
system requirements that apply to the driver seating position. They are
already familiar with the equipment and manufacturing processes
involved to certify their vehicles to seat belt warning system
requirements. Further, we anticipate that final-stage manufacturers
will base their vehicles on incomplete vehicles that already have the
seat belt reminder system installed rather than install the systems
themselves.
For final-stage manufacturers working with incomplete vehicles that
do not have rear seats or seat belt reminder systems already installed,
we believe that completing vehicles to meet the requirements would be
practicable. The manufacturers can obtain seats and seat belt systems
(with seat belt warning system) from suppliers. NHTSA recognizes that
the suppliers might be supplying larger vehicle manufacturers during
the development and lead time period, and do not have the capabilities
to handle all of the smaller manufacturers, including final-stage
manufacturers. The rulemaking accounts for this limitation by allowing
final-stage manufacturers an additional year to comply with the
requirements, to provide flexibility to these small entities and reduce
the economic impact of the rule on them. (See also 49 CFR 571.8(b).)
For an alterer (a person who alters by addition, substitution or
removal of components, other than readily attachable components, a
certified vehicle before the first purchase of the vehicle other than
for resale), the impacts of the rule will not be significant. The final
rule allows alterers an additional year to comply with the
requirements. For example, if an alterer is removing rear seats, the
person making the alteration would simply have to be careful not to
render non-compliant the seat belt warning system for the remaining
seats. (See 49 CFR 571.8(b).)
An alterer that is adding rear seats could obtain seating systems
with seat belt warning systems from seat suppliers and install the
seats on the body following the instructions of the seat supplier.
Changes may have to be made to the instrument panel area to add the
requisite visual signal, but the final rule provides flexibility to
manufacturers in providing the visual signal.
Executive Order 13132 (Federalism)
NHTSA has examined this rule pursuant to Executive Order 13132 (64
FR 43255; Aug. 10, 1999) and concluded that no additional consultation
with States, local governments, or their representatives is mandated
beyond the rulemaking process. The agency has concluded that the rule
does not have sufficient federalism implications to warrant
consultation with State and local officials or the preparation of a
federalism summary impact statement. The rule does not have
``substantial direct effects on the States, on the relationship between
the national government and the States, or on the distribution of power
and responsibilities among the various levels of government.''
NHTSA rules can have preemptive effect in two ways. First, the
National Traffic and Motor Vehicle Safety Act contains an express
preemption provision: When a motor vehicle safety standard is in effect
under this chapter, a State or a political subdivision of a State may
prescribe or continue in effect a standard applicable to the same
aspect of performance of a motor vehicle or motor vehicle equipment
only if the standard is identical to the standard prescribed under this
chapter. 49 U.S.C. 30103(b)(1). It is this statutory command by
Congress that preempts any non-identical State legislative and
administrative law address the same aspect of performance.
The express preemption provision described above is subject to a
savings clause under which ``[c]compliance with a motor vehicle safety
standard prescribed under this chapter does not exempt a person from
liability at common law.'' 49 U.S.C. 30103(e). Pursuant to this
provision, State common law tort causes of action against motor vehicle
manufacturers that might otherwise be preempted by the express
preemption provision are generally preserved.
NHTSA rules can also preempt State law is if complying with the
FMVSS would render the motor vehicle manufacturers liable under State
tort law. Because most NHTSA standards established by an FMVSS are
minimum
[[Page 457]]
standards, a State common law tort cause of action that seeks to impose
a higher standard on motor vehicle manufacturers will generally not be
preempted. However, if and when such a conflict does exist--for
example, when the standard at issue is both a minimum and a maximum
standard--the State common law tort cause of action is impliedly
preempted. See Geier v. American Honda Motor Co., 529 U.S. 861 (2000).
Pursuant to Executive Order 13132, NHTSA has considered whether
this rule could or should preempt State common law causes of action.
The agency's ability to announce its conclusion regarding the
preemptive effect of one of its rules reduces the likelihood that
preemption will be an issue in any subsequent tort litigation.
To this end, the agency has examined the nature (e.g., the language
and structure of the regulatory text) and objectives of this rule and
finds that this rule, like many NHTSA rules, would prescribe only a
minimum safety standard. NHTSA does not intend that this rule preempt
state tort law that would effectively impose a higher standard on motor
vehicle manufacturers than that established by this rule. Establishment
of a higher standard by means of State tort law would not conflict with
the standards in this final rule. Without any conflict, there could not
be any implied preemption of a State common law tort cause of action.
National Environmental Policy Act
NHTSA has analyzed this rule for the purposes of the National
Environmental Policy Act. In accordance with 49 CFR 1.81, 42 U.S.C.
4336, and DOT NEPA Order 5610.1C, NHTSA has determined that this rule
is categorically excluded pursuant to 23 CFR 771.118(c)(4) (planning
and administrative activities, such as promulgation of rules, that do
not involve or lead directly to construction). This rulemaking, which
amends Federal Motor Vehicle Safety Standard (FMVSS) No. 208,
``Occupant crash protection,'' to require a seat belt use warning
system for rear seats, updates and enhances the current seat belt
warning requirements for the driver's seat belt, and extends these
requirements to the front outboard passenger seat, is not anticipated
to result in any environmental impacts, and there are no extraordinary
circumstances present in connection with this rulemaking.
Executive Order 12988 (Civil Justice Reform)
With respect to the review of the promulgation of a new regulation,
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
4729, February 7, 1996) requires that Executive agencies make every
reasonable effort to ensure that the regulation: (1) Clearly specifies
the preemptive effect; (2) clearly specifies the effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct, while promoting simplification and burden reduction;
(4) clearly specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
Pursuant to Executive Order 12988, NHTSA notes as follows. The
issue of preemption is discussed above in connection with Executive
Order 13132. NHTSA notes further that there is no requirement that
individuals submit a petition for reconsideration or pursue other
administrative proceeding before they may file suit in court.
Paperwork Reduction Act
Under the procedures established by the Paperwork Reduction Act of
1995 (PRA) (44 U.S.C. 3501, et seq.), a Federal agency must request and
receive approval from the Office of Management and Budget (OMB) before
it collects certain information from the public and a person is not
required to respond to a collection of information by a Federal agency
unless the collection displays a valid OMB control number. In
compliance with these requirements, NHTSA is submitting an information
collection request (ICR) to OMB for approval for modifications to a
currently approved information collection titled ``Consolidated Vehicle
Owner's Manual Requirements for Motor Vehicles and Motor Vehicle
Equipment'' (OMB Control No. 2127-0541, Current Expiration Date: 03/31/
2026).
This final rule amends 49 CFR 571.208 to, among other things, add
new owner's manual requirements. NHTSA submitted an ICR to OMB for
review when the NPRM was published.\247\ OMB deferred review until
after receiving NHTSA's summary and response to all comments related to
the information collection requirements contained in this rulemaking.
Accordingly, NHTSA is resubmitting the ICR for this final rule.
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\247\ https://www.reginfo.gov/public/do/PRAViewICR?ref_nbr=202308-2127-002#.
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NHTSA's ICR describes the nature of the information collections and
their expected burden. The ICR is for fifteen mandatory and voluntary
disclosure requirements for manufacturers of motor vehicles and items
of motor vehicle equipment. Pursuant to 49 U.S.C. 30117, the Secretary
(NHTSA by delegation) is authorized to require manufacturers to provide
information to first purchasers of motor vehicles or items of motor
vehicle equipment related to performance and safety in printed
materials that are attached to or accompany the motor vehicle or item
of motor vehicle equipment. NHTSA has exercised this authority to
require manufacturers to provide certain specified safety information
to be readily available to consumers and purchasers of motor vehicles
and items of motor vehicle equipment. This information is most often
provided in vehicle owners' manuals and the requirements are found in
49 CFR parts 563, 571, and 575. Some of these requirements are
contained in the Federal Motor Vehicle Safety Standards (FMVSS) that
set performance requirements for motor vehicles and items of motor
vehicle equipment. The other requirements are contained in separate
regulations. Manufacturers must comply with these requirements whenever
they manufacture a vehicle or equipment item that is subject to the
requirements. The purpose of the required disclosures is to provide
important safety information to vehicle owners.
This final rule makes changes to existing an information collection
requiring that the owner's manual describe the vehicle's seat belt
warning system features, including the location, format, and meaning of
the visual warnings. It also requires that the owner's manual include
instructions on how to make any manual electrical connections for
readily removable seats. These changes are finalized without any
substantive changes from those proposed in the NPRM.
We received comments on the proposed changes. ASC supported the
proposed changes to the owner's manual requirements. NSC suggested
standardizing generic nomenclature and warning and icon symbols to
reduce driver confusion. Regarding installation of child restraint
systems, Auto Innovators emphasized that additional information about
system design can be included at the discretion of the manufacturer,
and SRN suggested that instructions regarding how to interpret certain
warnings should be included in
[[Page 458]]
the child passenger section of the manual. These comments are discussed
in Section VI.A.2.d.
As described in the NPRM, NHTSA estimates that the total burden of
the ICR is approximately 10,172 hours and $8,726,501 annually. This
burden represents an increase in estimated burden hours of 1,544 hours
(8,628 hours to 10,172 hours) and an increase in costs of $755,040
($7,971,461 to $8,726,501), compared with existing requirements. The
change in burden reflects changes as a result of the rulemaking
requiring the development and publication of new information for the
owner's manual. Printing costs have increased due to accounting for the
estimated number of vehicles that will be equipped with seat belt
reminder systems and will therefore need to comply with the
requirements to provide system information and operating instructions.
We did not receive comments on these burden estimates or other aspects
of the proposed revision to the information collection. These burden
estimates did not change between the NPRM and final rule.
National Technology Transfer and Advancement Act
Under the National Technology Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104-113), ``all Federal agencies and departments shall
use technical standards that are developed or adopted by voluntary
consensus standards bodies, using such technical standards as a means
to carry out policy objectives or activities determined by the agencies
and departments.'' Voluntary consensus standards are technical
standards (e.g., materials specifications, test methods, sampling
procedures, and business practices) that are developed or adopted by
voluntary consensus standards bodies, such as SAE (formerly, the
Society of Automotive Engineers). The NTTAA directs this agency to
provide Congress, through OMB, explanations when the agency decides not
to use available and applicable voluntary consensus standards.
While the agency is not aware of any voluntary standards that exist
regarding the seat belt warnings contemplated in this rule, the agency
has examined relevant regulations in other countries, such as the
European Union standard ECE R16. As discussed above, although we are
not aware of any foreign regulations that require seat belt warnings
for the front outboard passenger or rear seat belts or for the driver
seat on small buses, we believe that requiring seat belt warnings for
these seating positions and for the driver seats on small buses meets a
safety need and is practicable.
Severability
The issue of severability of FMVSS is addressed in 49 CFR 571.9. It
provides that if any FMVSS or its application to any person or
circumstance is held invalid, the remainder of the part and the
application of that standard to other persons or circumstances is
unaffected.
Unfunded Mandates Reform Act
The Unfunded Mandates Reform Act of 1995 (Pub. L. 104-4) (UMRA)
requires agencies to prepare a written assessment of the costs,
benefits, and other effects of proposed or final rules that include a
Federal mandate likely to result in the expenditures by States, local
or tribal governments, in the aggregate, or by the private sector, of
$100 million or more (adjusted annually for inflation with base year of
1995) in any one year. Adjusting this amount by the implicit gross
domestic product price deflator for 2022 results in $177 million
(111.416/75.324 = 1.48). The assessment may be included in conjunction
with other assessments, as it is here.
UMRA requires the agency to select the ``least costly, most cost-
effective or least burdensome alternative that achieves the objectives
of the rule.'' As discussed above, the agency considered alternatives
to the final rule and has concluded that the requirements are the most
cost-effective alternatives that achieve the objectives of the rule.
This rule on seat belt reminder systems is not likely to result in
expenditures by State, local or tribal governments of more than $177
million annually. However, it is estimated to result in the expenditure
by automobile manufacturers and/or their suppliers by approximately
$168 million annually. The estimated costs are discussed in Section
VIII, Overview of Benefits and Costs, and the docketed final regulatory
impact analysis.
We have concluded that the requirements in this rule are the most
cost-effective alternatives that achieve the objectives of the rule.
Plain Language
Executive Order 12866 and E.O. 13563 require each agency to write
all rules in plain language. Application of the principles of plain
language includes consideration of the following questions:
Have we organized the material to suit the public's needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?
NHTSA has considered these questions and attempted to use plain
language in writing this rule. Please inform the agency if you can
suggest how NHTSA can improve its use of plain language.
Regulation Identifier Number (RIN)
The Department of Transportation assigns a regulation identifier
number (RIN) to each regulatory action listed in the Unified Agenda of
Federal Regulations. The Regulatory Information Service Center
publishes the Unified Agenda in April and October of each year. You may
use the RIN contained in the heading at the beginning of this document
to find this action in the Unified Agenda.
Note: The following appendix will not appear in the Code of
Federal Regulations.
Appendix A. List of Comments Cited in Preamble
----------------------------------------------------------------------------------------------------------------
Commenter Comment ID
----------------------------------------------------------------------------------------------------------------
Advocates for Highway and Auto Safety and Public Citizen NHTSA-2023-0032-0040
(Advocates and Public Citizen).
Alliance for Automotive Innovation (Auto Innovators)..... NHTSA-2023-0032-0048
Automotive Safety Council (ASC).......................... NHTSA-2023-0032-0015
Autonomous Vehicle Industry Association (AVIA)........... NHTSA-2023-0032-0029
Braun Northwest, Inc. (BNW).............................. NHTSA-2023-0032-0050
Consumer Reports......................................... NHTSA-2023-0032-0049
Cross, Karleigh.......................................... NHTSA-2023-0032-0013
Dorey, Rivers............................................ NHTSA-2023-0032-0008
[[Page 459]]
Ford Motor Company (Ford)................................ NHTSA-2023-0032-0045
Freedman Seating Company (Freedman)...................... NHTSA-2023-0032-0041
Freeman, Paige........................................... NHTSA-2023-0032-0017
Gaal, Edward............................................. NHTSA-2023-0032-0010
General Motors (GM)...................................... NHTSA-2023-0032-0026
American Honda Motor Co. (Honda)......................... NHTSA-2023-0032-0039
Hyundai America Technical Center, Inc. (HATCI)........... NHTSA-2023-0032-0053
Hyundai Motor Company (Hyundai).......................... NHTSA-2023-0032-0047
IEE...................................................... NHTSA-2023-0032-0032
Insurance Institute for Highway Safety (IIHS)............ NHTSA-2023-0032-0020
InterMotive Vehicle Controls (InterMotive)............... NHTSA-2023-0032-0016
Koo, John................................................ NHTSA-2023-0032-0012
Mothers Against Drunk Driving (MADD)..................... NHTSA-2023-0032-0055
Mercedes-Benz and Mercedes-Benz Research and Development NHTSA-2023-0032-0025
North America (Mercedes).
National Association of Mutual Insurance Companies NHTSA-2023-0032-0034
(NAMIC).
National Automobile Dealers Association (NADA)........... NHTSA-2023-0032-0042
National Safety Council (NSC)............................ NHTSA-2023-0032-0038
Nissan North America..................................... NHTSA-2023-0032-0043
National Transportation Safety Board (NTSB).............. NHTSA-2023-0032-0019
Paradise, John........................................... NHTSA-2023-0032-0009
Recreational Vehicle Industry Association (RVIA)......... NHTSA-2023-0032-0028
Rivian Automotive........................................ NHTSA-2023-0032-0044
Safe Kids Worldwide (SKW)................................ NHTSA-2023-0032-0046
Safe Ride News (SRN)..................................... NHTSA-2023-0032-0036
Stange, Trenton.......................................... NHTSA-2023-0032-0018
Tesla.................................................... NHTSA-2023-0032-0035
Tombrello, Stephanie..................................... NHTSA-2023-0032-0030
Toyota Motor North America, Inc. and Toyota Motor NHTSA-2023-0032-0054
Corporation (Toyota).
Anonymous #5............................................. NHTSA-2023-0032-0005
Anonymous #24............................................ NHTSA-2023-0032-0024
Anonymous #33............................................ NHTSA-2023-0032-0033
----------------------------------------------------------------------------------------------------------------
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles.
In consideration of the foregoing, NHTSA amends 49 CFR part 571 as
set forth below.
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
0
1. The authority citation for part 571 of title 49 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.95.
0
2. Amend Sec. 571.101 by revising paragraph S5.5.6 and tables 1 and 2
to read as follows.
Sec. 571.101 Standard No. 101; Controls and displays.
* * * * *
S5.5.6(a) Except as provided in S5.5.6(b) and (c), messages
displayed in a common space may be cancelable automatically or by the
driver.
(b) Telltales for high beams, turn signal, low tire pressure, and
passenger air bag off, and telltales for which the color red is
required in table 1 to this section must not be cancelable while the
underlying condition for their activation exists.
(c) Telltales for the seat belts must not be cancelable by the
driver before the minimum durations are satisfied but may be
cancellable automatically as specified in FMVSS No. 208 (Sec.
571.208).
* * * * *
BILLING CODE 4910-59-P
[[Page 460]]
Table 1 to Sec. 571.101
[GRAPHIC] [TIFF OMITTED] TR03JA25.001
[[Page 461]]
[GRAPHIC] [TIFF OMITTED] TR03JA25.002
[[Page 462]]
[GRAPHIC] [TIFF OMITTED] TR03JA25.003
[[Page 463]]
[GRAPHIC] [TIFF OMITTED] TR03JA25.004
[[Page 464]]
[GRAPHIC] [TIFF OMITTED] TR03JA25.005
[[Page 465]]
Table 2 to Sec. 571.101
[GRAPHIC] [TIFF OMITTED] TR03JA25.006
BILLING CODE 4910-59-C
0
3. Amend Sec. 571.208 by:
0
a. Adding paragraphs S4.1.5.7, S4.1.5.7.1, S4.1.5.8, S4.1.5.8.1,
S4.2.8, S4.2.8.1, S4.2.9, S4.2.9.1, S4.4.3.4, S4.4.3.4.1, S4.4.3.5,
S4.4.3.5.1, and S4.5.1.(f)(3);
0
b. Revising paragraph S4.5.3.3(b); and
0
c. Adding paragraph S7.5.
The additions and revisions read as follows:
Sec. 571.208 Standard No. 208; Occupant crash protection.
* * * * *
S4.1.5.7. Front seat belt warnings for passenger cars manufactured
on or after September 1, 2026.
S4.1.5.7.1 Any front outboard designated seating position and any
inboard designated seating position for which a seat belt warning is
required in S4.1.5.6 shall comply with S7.5 of this standard.
S4.1.5.8. Rear seat belt warnings for passenger cars manufactured
on or after September 1, 2027.
S4.1.5.8.1. All rear designated seating positions, except in law
enforcement vehicles, shall comply with S7.5 of this standard.
* * * * *
S4.2.8 Front seat belt warnings for trucks and multipurpose
passenger vehicles manufactured on or after September 1, 2026 with a
GVWR of 4,536 kg (10,000 lb) or less.
S4.2.8.1. Any front outboard designated seating position certified
to a compliance option requiring a seat belt and any inboard designated
seating position for which a seat belt warning is required by S4.2.6.4
shall comply with S7.5 of this standard.
[[Page 466]]
S4.2.9 Rear seat belt warnings for trucks and multipurpose
passenger vehicles manufactured on or after September 1, 2027 with a
GVWR of 4,536 kg (10,000 lb) or less.
S4.2.9.1. All rear designated seating positions certified to a
compliance option requiring a seat belt, except ambulances, as defined
by FMVSS No. 201 (Sec. 571.201), and law enforcement vehicles, shall
comply with S7.5 of this standard.
* * * * *
S4.4.3.4 Front seat belt warnings for buses manufactured on or
after September 1, 2026 with a GVWR of 4,536 kg (10,000 lb) or less.
S4.4.3.4.1 All front outboard designated seating positions and any
inboard designated seating position for which a seat belt warning is
required by S4.2.6.4 shall comply with S7.5 of this standard.
S4.4.3.5 Rear seat belt warnings for buses manufactured on or after
September 1, 2027 with a GVWR of 4,536 kg (10,000 lb) or less.
S4.4.3.5.1 All rear designated seating positions certified to a
compliance option requiring a seat belt, except for school buses and
law enforcement vehicles, shall comply with S7.5 of this standard.
* * * * *
S4.5.1 * * *
(f) * * *
(3) The owner's manual (which includes information provided by the
vehicle manufacturer to the consumer, whether in digital or printed
form) for any vehicle equipped with a seat belt warning system must
include an accurate description of the system features and warning
signals, including the location and format of the visual warnings, in
an easily understandable format. The description shall include
information on when the different features of the warning system will
activate and how to interpret the visual warnings. For vehicles with
any rear designated seating position that is a readily-removable seat
(a seat designed to be easily removed and replaced by means installed
by the manufacturer for that purpose) equipped with manual electrical
connections that are utilized by the rear seat belt warning system, the
owner's manual must include a description of the purpose of the
connection, instructions on how to achieve a proper connection, and a
description of how not achieving a proper connection may affect the
proper functioning of the system.
* * * * *
S4.5.3.3 * * *
(b) Conform to the seat belt warning system requirements of S7.3 or
S7.5 of this standard, as applicable.
* * * * *
S7.5 Seat belt warning systems for front outboard seat belt
assemblies in vehicles manufactured on or after September 1, 2026
provided in accordance with the requirements of S4.1.5.7, S4.2.8,
S4.4.3.4, and S4.5.3.3 of this standard, and rear seat belt assemblies
in vehicles manufactured on or after September 1, 2027 provided in
accordance with the requirements of S4.1.5.8, S4.2.9, S4.4.3.5, and
S4.5.3.3 of this standard.
(a) Definitions for S7.5. (1) A manual seat belt is not in use when
the seat belt latch mechanism is not fastened. A seat belt is in use
when the seat belt latch mechanism is fastened. An automatic seat belt
is not in use when the seat belt latch mechanism is not fastened or, if
the automatic belt is non-detachable, the emergency release mechanism
is in the released position. If the automatic seat belt is motorized,
whether the seat belt is in use is determined when the seat belt
webbing is in its locked protective mode at the anchorage point.
(2) A warning cycle for an intermittent audible warning consists of
period(s) when the warning is active at the chime frequency or
continuously, and of inactive period(s). A warning cycle begins with an
active period and is 30 seconds in duration.
(3) Chime frequency means the repetition rate for an intermittent
audible warning when the warning is active.
(4) Duty cycle means the total amount of time an intermittent
audible warning is active during a warning cycle at the chime frequency
or continuously, divided by the total warning cycle duration (30
seconds).
(5) A readily-removable seat means a seat designed to be easily
removed and replaced by means installed by the manufacturer for that
purpose.
(6) Seat centerline means the line formed by the intersection of
the seating surface and the vertical plane that passes through the
``seating reference point'' (as defined at 49 CFR 571.3) and is
parallel to the direction that the seat faces.
(b) Front seat belt warning system. A driver's designated seating
position and any front outboard passenger designating seating position
must be equipped with an audio-visual seat belt warning meeting the
requirements of S7.5(b)(1) through (4) when tested in accordance with
S7.5(d).
(1) Visual warning. (i) A visual warning must activate and remain
active whenever the ignition switch is in the ``on'' or ``start''
position (or the propulsion system is activated), the seat is occupied,
and the seat belt is not in use.
(ii) Vehicles with a driver's designated seating position. The
visual warning for the driver's seat belt and the visual warning for
the front outboard passenger seat belt must be visible from the
driver's seat. If the vehicle has a mode of driverless operation, the
visual warning for the front outboard passenger seat belt must also be
visible from the front outboard passenger seat.
(iii) Vehicles without a driver's designated seating position. The
visual warning for each outboard passenger designated seating position
must be visible from each outboard passenger designated seating
position.
(iv) The visual warning may be continuous or intermittent and must
display the identifying symbol or the words specified in table 2 of
FMVSS No. 101 (Sec. 571.101).
(v) For a visual warning associated with multiple front outboard
seats, the visual warning must clearly identify the seating positions
for which the warnings are intended.
(vi) The visual warning must not be overridden by other warnings.
(2) Audible warning--first phase. (i) An audible warning must
activate when the ignition switch is placed in the ``on'' or ``start''
position (or upon manual activation of the propulsion system, but prior
to the vehicle being placed in ``possible active driving mode'' as
defined by FMVSS No. 305 (Sec. 571.305)), the seat is occupied, and
the seat belt is not in use.
(ii) The audible warning must continue for 30 seconds, until the
seat belt that triggered the warning is in use, until the seat is no
longer occupied, or until the second-phase warning activates, whichever
comes first. The audible warning may be paused during the activation of
another audible safety warning that is designed to alert the driver to
take immediate action, but the seat belt audible warning must be
resumed for the remainder of the required duration after the other
audible warning deactivates.
(iii) The audible warning may be continuous or intermittent. If
intermittent, inactive periods longer than 3 seconds will not be
counted toward the total duration of the audible warning, and there
must be no inactive periods greater than 10 seconds. The same audible
warning may be used for all front and rear seats.
(3) Audible warning--second phase. (i) The audible warning must
activate and remain active when the vehicle
[[Page 467]]
speed is equal to or greater than 10 km/h (6.2 mph), the seat is
occupied, and the seat belt is not in use. The audible warning may be
paused during the activation of another audible safety warning that is
designed to alert the driver to take immediate action, but the seat
belt audible warning must be resumed after the other audible warning
deactivates.
(ii) The audible warning may be continuous or intermittent. If
intermittent, the audible warning when active must be continuous or
have a chime frequency of at least 0.5 Hz and a duty cycle of at least
0.2. The same audible warning may be used for all front and rear seats.
(4) Cancellation. The warning must not be able to be canceled or
deactivated.
(c) Rear passenger seat belt warning system. All rear designated
seating positions must be equipped with a warning system meeting the
requirements of S7.5(c)(1) through (7) when tested in accordance with
S7.5(d).
(1) Start-of-trip warning. A visual warning indicating how many or
which rear seat belts are in use and/or not in use must activate when
the ignition switch is placed in the ``on'' or ``start'' position (or
upon manual activation of the propulsion system, but prior to the
vehicle being placed in ``possible active driving mode'' as defined by
FMVSS No. 305 (Sec. 571.305)) and continue for at least 60 seconds.
(i) No visual warning is required for:
(A) an unoccupied seat if the system is able to determine whether
or not a seat is occupied;
(B) a seat belt that is in use in a system designed to indicate to
the driver how many or which rear seat belts are not in use; and
(C) a seat belt that is not in use in a system designed to indicate
to the driver how many or which rear seat belts are in use.
(2) Change-of-status warning. An audio-visual warning indicating
how many or which rear seat belts have undergone a change of status
from in use to not in use must activate when the status of any rear
seat belt changes from in use to not in use and the vehicle is in
forward or reverse drive mode, unless any rear door is open. The
warning must continue for at least 30 seconds or until the seat belt
that triggered the warning is in use. The warning may deactivate if the
system is able to determine that the number of seat belts in use is
restored and all the doors remained closed.
(3) Additional visual warning requirements. (i) The warning may be
continuous or intermittent and may consist of text, symbols, and/or
numbers.
(ii) The warning must be visible from the driver's seat.
(iii) If the warning is designed to indicate how many or which rear
seat belts are in use, the color of the symbols or numbers indicating
seat belts in use must be green. If the warning is designed to indicate
to the driver how many or which rear seat belts are not in use, the
color of the symbols or numbers indicating seat belts not in use must
be red.
(iv) The change-of-status visual warning may use the same telltale
as the start of trip warning, provided that the color of an illuminated
symbol or number used to indicate to the driver how many or which rear
seat belts have undergone a change of status from in use to not in use
is red.
(v) The warning must not be overridden by other visual warnings for
the required duration.
(4) Audible warning requirements. (i) The audible warning may be
continuous or intermittent. If intermittent, inactive periods longer
than 3 seconds will not be counted toward the total duration of the
warning, and there must be no inactive periods greater than 10 seconds.
(ii) The audible warning may be paused during the activation of
another audible safety warning that is designed to alert the driver to
take immediate action, but the seat belt audible warning must be
resumed for the remainder of the required duration after the other
audible warning deactivates.
(iii) The same audible warning may be used for all front and rear
seats.
(5) Cancellation. The warning must not be able to be canceled or
deactivated.
(6) Seat electrical connection requirements. Any rear designated
seating position consisting of a readily-removable seat that is
equipped with electrical connections utilized by the rear seat belt
warning system must either--
(i) Automatically connect the electrical connections when the seat
is put in place; or
(ii) If a manual electrical connection is required, the connectors
must be readily accessible.
(7) Electrical connection warning signal. Vehicles that provide a
visual warning designed to indicate to the driver how many or which
rear seat belts are not in use and are equipped with any readily
removable rear seats must, when the ignition switch is placed in the
``on'' or ``start'' position (or upon manual activation of the
propulsion system, but prior to the vehicle being placed in ``possible
active driving mode'' as defined by FMVSS No. 305 (Sec. 571.305))
provide a visual warning visible from the driver's seat if a seat has
been installed and a proper electrical connection has not been made.
The visual warning may be intermittent but must remain active until all
rear seat electrical connections are properly made.
(d) Test procedures. (1) Occupied designated seating positions. If
testing with a designated seating position occupied, the following
apply, at the option of the manufacturer:
(i) Front outboard seating positions. (A) Seat the 5th percentile
female test dummy described in part 572, subpart O of this chapter, as
well as any larger dummy described in part 572 of this chapter; or
(B) Seat any human occupant that weighs 46.7 kg (103 lb) or more
and is 139.7 cm (55 inches) tall or taller.
(ii) Driver's seating position. (A) Seat the 5th percentile female
test dummy described in part 572, subpart O of this chapter, as well as
any larger dummy described in part 572 of this chapter;
(B) Seat any human occupant that weighs 46.7 kg (103 lb) or more
and is 139.7 cm (55 inches) tall or taller; or
(C) The seat may be considered occupied when the ignition switch is
in the ``on'' or ``start'' position (or the propulsion system is
activated).
(iii) Rear seating positions. (A) Seat the 6-year-old child dummy
described in part 572, subpart N of this chapter, as well as any larger
dummy described in part 572 of this chapter; or
(B) Seat any human occupant that weighs 21 kg (46.5 lb) or more and
is 114 cm (45 inches) tall or taller.
(iv) Compliance option selection. The manufacturer shall select a
compliance option by the time it certifies the vehicle and may not
thereafter select a different option for the vehicle. Each manufacturer
shall provide information to NHTSA regarding which of the compliance
options it has selected for a particular vehicle or make/model upon
request.
(2) Seating procedures--(i) Seat adjustment. If adjustable, the
seat back shall be placed in the manufacturer's nominal design riding
position, with any other seat adjustments in any position, and any
adjustable seat belt anchorages in any position.
(ii) Test dummy. Seat the test dummy such that the midsagittal
plane of the dummy is vertical and within 10 mm of the seat
centerline, with the torso and pelvis in contact with the seat back.
The dummy may be clothed in any manner.
(iii) Human occupant. The occupant shall assume, to the extent
possible, the
[[Page 468]]
final physical position specified for the test dummy. The occupant may
be clothed in any manner.
(3) Verify that the seat belt warnings function as specified in
S7.5(b) and (c) for any combination of seat belt use (at any seating
position), seat occupancy (at any seating position), removable seat
electrical connection status (connected or not connected, for any
removable seat), vehicle speed, and door status (open or closed, for
any door), except that the door shall not be opened when the vehicle is
in motion.
Issued in Washington, DC, under authority delegated in 49 CFR
1.95 and part 501.
Adam Raviv,
Chief Counsel.
[FR Doc. 2024-30340 Filed 1-2-25; 8:45 am]
BILLING CODE 4910-59-P