[Federal Register Volume 87, Number 135 (Friday, July 15, 2022)]
[Rules and Regulations]
[Pages 42339-42373]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 2022-14330]
=======================================================================
-----------------------------------------------------------------------
DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. NHTSA-2022-0053]
RIN 2127-AL58
Federal Motor Vehicle Safety Standards; Rear Impact Guards, Rear
Impact Protection
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation (DOT).
ACTION: Final rule.
-----------------------------------------------------------------------
SUMMARY: This final rule upgrades NHTSA's safety standards addressing
rear underride protection in crashes of passenger vehicles into
trailers and semitrailers by adopting similar requirements to Transport
Canada's standard for rear impact guards. Adopting these standards will
require rear impact guards to provide sufficient strength and energy
absorption to protect occupants of compact and subcompact passenger
cars impacting the rear of trailers at 56 kilometers per hour (km/h)
(35 miles per hour (mph)). Upgraded protection will be provided in
crashes in which the passenger motor vehicle hits: the center of the
rear of the trailer or semitrailer; and, in which 50 percent of the
width of the passenger motor vehicle overlaps the rear of the trailer
or semitrailer. This rulemaking commenced in response to petitions for
rulemaking from the Insurance Institute for Highway Safety (IIHS) and
from Ms. Marianne Karth and the Truck Safety Coalition (TSC). This
final rule responds to and fulfills the rulemaking mandate of the
November 2021 Bipartisan Infrastructure Law (BIL) that directs the
Secretary to upgrade current Federal safety standards for rear impact
guards. NHTSA is also issuing this final rule pursuant to DOT's January
2022 National Roadway Safety Strategy, which describes the five key
objectives of the Department's Safe System Approach: safer people,
safer roads, safer vehicles, safer speeds, and post-crash care. One of
the key Departmental actions to enable safer vehicles is to issue a
final rule to upgrade existing requirements for rear impact guards on
newly manufactured trailers and semitrailers.
DATES:
Effective date: This final rule is effective on January 11, 2023.
Compliance date: July 15, 2024. Optional early compliance is
permitted.
Petitions for reconsideration: Petitions for reconsideration of
this final rule must be received no later than August 29, 2022.
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, West Building, Washington, DC 20590. All petitions
received will be posted without change to https://www.regulations.gov,
including any personal information provided.
Privacy Act: DOT will post any petition for reconsideration, and
any other submission, without edit, to www.regulations.gov, as
described in the system of records notice, DOT/ALL-14 FDMS, accessible
through https://www.transportation.gov/individuals/privacy/privacy-act-system-records-notices. Anyone is able to search the electronic form of
all submissions to any of our dockets by the name of the individual
submitting the submission (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 (65 FR 19477-78).
FOR FURTHER INFORMATION CONTACT: For technical issues: Ms. Lina
Valivullah, National Highway Traffic Safety Administration, 1200 New
Jersey Avenue SE, West Building, Washington, DC 20590 (telephone) 202-
366-8786, (email) [email protected].
For legal issues: Ms. Deirdre Fujita, Office of the Chief Counsel,
National Highway Traffic Safety Administration, 1200 New Jersey Avenue
SE, West Building, Washington, DC 20590, (telephone) 202-366-2992,
(email) [email protected].
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
a. Overview
b. NHTSA's Statutory Authority and Response to BIL
1. National Traffic and Motor Vehicle Safety Act
2. Bipartisan Infrastructure Law
3. Implementation of BIL
c. DOT National Roadway Safety Strategy
d. NTSB Recommendation
e. Impacts of This Rulemaking
f. No Significant Changes to the NPRM
II. Background
a. Current Requirements
b. Petitions
c. Summary of Proposed Changes
III. Summary of Comments
IV. Response to Comments on the Proposed Amendments
[[Page 42340]]
a. General Strength and Energy Absorption Requirements
b. Alternative Guard Designs
c. 700 kN Energy Absorption Test Option
d. Ground Clearance
e. Requiring Attachment Hardware To Remain Intact
f. Definition of Rear Extremity
g. Low Chassis Vehicle Correction
h. Technical Correction
V. Response to Comments on Issues Not Proposed in the NPRM
a. Vehicles Excluded From FMVSS No. 224
b. Testing on a Trailer Rather Than a Fixture
c. Low Overlap Crash Performance
d. Half-Guard Testing
e. Retrofitting
VI. Lead Time
VII. Benefit-Cost Analysis
VIII. Regulatory Notices and Analyses
I. Executive Summary
a. Overview
NHTSA is issuing this final rule to upgrade Federal Motor Vehicle
Safety Standard (FMVSS) No. 223, ``Rear impact guards,'' and FMVSS No.
224, ``Rear impact protection,'' which together provide protection for
occupants of passenger vehicles in crashes into the rear of trailers
and semitrailers. FMVSS No. 223, an equipment standard, specifies
strength and energy absorption requirements in quasi-static force tests
of rear impact guards sold for installation on new trailers and
semitrailers. FMVSS No. 224, a vehicle standard, requires new trailers
and semitrailers with a gross vehicle weight rating (GVWR) of 4,536
kilogram (kg) (10,000 pounds (lb)) or more to be equipped with a rear
impact guard meeting FMVSS No. 223.\1\ The notice of proposed
rulemaking (NPRM) preceding this final rule was published on December
16, 2015.\2\
---------------------------------------------------------------------------
\1\ NHTSA established the two-standard approach to address
compliance burdens on small trailer manufacturers, of which there is
a significant number. Under FMVSS No. 223, the guard may be tested
for compliance while mounted to a test fixture or to a complete
trailer, at the manufacturer's option. FMVSS No. 224 requires the
guard to be mounted on the trailer or semitrailer in accordance with
the instructions provided with the guard by the guard manufacturer.
Under this two-standard approach, a small manufacturer that produces
relatively few trailers can certify its trailers to FMVSS No. 224
with assurance without having to undertake destructive testing of
what could be a substantial portion of its production. The two-
standard approach was designed to provide small trailer
manufacturers a practicable and reasonable means of certifying to
FMVSS No. 224.
\2\ 80 FR 78417.
---------------------------------------------------------------------------
Rear underride crashes occur when a passenger vehicle crashes into
the rear end of a generally larger vehicle, and the front end of the
passenger vehicle slides under (i.e., underrides) the rear end of the
larger vehicle. Underride may occur in collisions between a passenger
vehicle and the rear end of a large trailer or semitrailer (referred to
in this rule collectively as ``trailers'') because the bed and chassis
of the trailer is often higher than the front of the passenger vehicle.
In extreme underride crashes, ``passenger compartment intrusion'' (PCI)
may occur when the passenger vehicle underrides the rear end of the
trailer to such an extent that the rear end of the trailer strikes and
enters the passenger compartment of the colliding passenger vehicle.
PCI can result in severe injuries and fatalities to the occupants of
the passenger vehicle.
Rear impact guards are mounted on the rear of trailers to prevent
underride and PCI. In a collision between a passenger vehicle and the
rear of a trailer equipped with a rear impact guard, the rear impact
guard engages the striking passenger vehicle and prevents it from
sliding too far under the struck vehicle's bed and chassis. FMVSS Nos.
223 and 224 ensure a rear impact guard is configured low and wide to
impede a striking passenger vehicle, is strong enough to withstand a 48
km/h (30 mph) impact of the colliding vehicle, and has energy-absorbing
capability to further mitigate harm to occupants in the striking
vehicle.
NHTSA designed FMVSS No. 223 and 224 to work in conjunction with
FMVSS No. 208, ``Occupant crash protection,'' so that occupants are
protected with seat belts and air bags in the underride crash--thus
maximizing the likelihood of avoiding serious or fatal injury in the
impact into the guard. When FMVSS Nos. 223 and 224 were issued in 1996,
FMVSS No. 208 required passenger cars to provide crash protection in a
48 km/h (30 mph) rigid barrier crash test. The agency designed the
underride protection standards so that occupants would be reasonably
protected in underride crashes up to 48 km/h (30 mph). Since then,
FMVSS No. 208's test speed has been increased to provide high levels of
occupant protection in a 56 km/h (35 mph) frontal crash.
With FMVSS No. 208 now providing crash protection up to 56 km/h (35
mph), NHTSA is amending FMVSS Nos. 223 and 224 to mandate the guards
withstand crash velocities up to that speed. This final rule adopts
requirements of Canada Motor Vehicle Safety Standard (CMVSS) No. 223,
``Rear impact guards.'' \3\ CMVSS No. 223 requires rear impact guards
with sufficient strength and energy absorption capability to protect
occupants of compact and subcompact passenger cars impacting the rear
of trailers at 56 km/h (35 mph). Under this final rule, the impacting
vehicle's FMVSS No. 208 occupant protection technologies could absorb
enough of the crash forces from the impact to reduce significantly the
risk of fatality and serious injury to occupants of the colliding
vehicle. As the current requirements in FMVSS Nos. 223 and 224 were
developed with the intent of providing underride crash protection to
occupants of passenger vehicles in impacts up to 48 km/h (30 mph),
increasing the robustness of the trailer/guard design such that it will
be able to withstand crash velocities up to 56 km/h (35 mph) represents
a substantial increase in the stringency of our standards. There is a
36 percent increase in crash energy in a 56 km/h (35 mph) impact of a
vehicle compared to a 48 km/h (30 mph) impact of the same vehicle.
---------------------------------------------------------------------------
\3\ This final rule also adopts Transport Canada's definition of
``rear extremity'' to define where aerodynamic fairings are to be
located on a trailer to avoid posing a safety hazard in rear
underride crashes.
---------------------------------------------------------------------------
This final rule is based on the best available science. The
underlying field data used in the December 16, 2015 NPRM and this final
rule are from a 2013 NHTSA-funded study conducted by the University of
Michigan Transportation Research Institute (UMTRI) to supplement
UMTRI's Trucks Involved in Fatal Accidents (TIFA) survey data for years
2008 and 2009. (The 2013 NHTSA-funded study is referred to in this
preamble as the 2013 UMTRI Study.) 4 5 The TIFA database had
analyzed FARS data to obtain more detailed information on fatal large
truck crashes, and had provided more detailed information than in FARS
on the involved large trucks, motor carriers, and sequence of events
leading to the crash.\6\ The 2013 UMTRI Study supplemented these TIFA
data by collecting specific data pertaining to trailer rear extremity
crashes. In the 2013 UMTRI Study, UMTRI also determined whether a rear
impact guard was required, and if not required, the criterion that had
excluded the vehicle. The 2013 UMTRI Study collected detailed
information on fatal vehicle crashes into the rear of trailers, the
relative impact velocity, and the extent of underride in these crashes.
The data from the 2013 UMTRI Study
[[Page 42341]]
enabled NHTSA to establish national estimates of rear impact crashes
into heavy vehicles that resulted in PCI. Because of the detailed
analysis and the supplemental information collected for each crash, the
2013 UMTRI Study forms the most comprehensive and valid data set
available to inform NHTSA about crashes involving trucks and trailers
and the incidence and extent of underride.
---------------------------------------------------------------------------
\4\ NHTSA discussed the results of this study in detail in
Appendix A of the NPRM. See 80 FR 78447-78452.
\5\ Heavy-Vehicle Crash Data Collection and Analysis to
Characterize Rear and Side Underride and Front Override in Fatal
Truck Crashes, DOT HS 811 725, March 2013, https://www.nhtsa.gov/sites/nhtsa.gov/files/811725.pdf.
\6\ The TIFA survey data contain data for all trucks with a GVWR
greater than 4,536 kg (10,000 lb) that were involved in fatal
traffic crashes in the 50 U.S. States and the District of Columbia.
---------------------------------------------------------------------------
b. NHTSA's Statutory Authority and Response to BIL
1. National Traffic and Motor Vehicle Safety Act
This final rule is issued under the National Traffic and Motor
Vehicle Safety Act (Safety Act) (49 U.S.C. 30101 et seq.). Under the
Safety Act, the Secretary of Transportation (NHTSA by delegation) \7\
is responsible for prescribing motor vehicle safety standards that are
practicable, meet the need for motor vehicle safety, and are stated in
objective terms.\8\ ``Motor vehicle safety'' is defined in the Safety
Act 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.''
\9\ ``Motor vehicle safety standard'' means a minimum performance
standard for motor vehicles or motor vehicle equipment.\10\ When
prescribing such standards, the agency must consider all relevant,
available motor vehicle safety information, and consider whether a
standard is reasonable, practicable, and appropriate for the types of
motor vehicles or motor vehicle equipment for which it is
prescribed.\11\ The agency must also consider the extent to which the
standard will further the statutory purpose of reducing traffic crashes
and associated deaths.\12\
---------------------------------------------------------------------------
\7\ 49 CFR 1.95. The Secretary also delegated to NHTSA the
authority set out for Section 101(f) of Public Law 106-159 to carry
out, in coordination with the Federal Motor Carrier Safety
Administrator, the authority vested in the Secretary by subchapter
311 and section 31502 of title 49, U.S.C., to promulgate safety
standards for commercial motor vehicles and equipment subsequent to
initial manufacture when the standards are based upon and similar to
a Federal Motor Vehicle Safety Standard promulgated, either
simultaneously or previously, under chapter 301 of title 49, U.S.C.
\8\ 49 U.S.C. 30111(a).
\9\ 49 U.S.C. 30102(a)(8).
\10\ 49 U.S.C. 30102(a)(9).
\11\ 49 U.S.C. 30111(b).
\12\ Id.
---------------------------------------------------------------------------
2. Bipartisan Infrastructure Law
On November 15, 2021, President Biden signed the Infrastructure
Investment and Jobs Act (IIJA),\13\ commonly referred to as the
Bipartisan Infrastructure Law (BIL). Section 23011 of BIL specifies
provisions for underride protection measures for trailers and
semitrailers. As discussed in detail below, the provisions direct the
Secretary to upgrade current Federal safety standards for rear impact
guards and conduct additional research, report to Congress on the
effectiveness, feasibility, costs, and benefits of side guards,
establish an advisory committee on underride protection, and implement
the recommendations issued by the Government Accountability Office
(GAO) on improved data collection, inspection and research of truck
underride guards.
---------------------------------------------------------------------------
\13\ Public Law 117-58.
---------------------------------------------------------------------------
Section 23011(b)(1)(A) of BIL states that, not later than 1 year
after the date of enactment of the Act, the Secretary shall promulgate
regulations that revise FMVSS No. 223 and FMVSS No. 224 to require new
trailers and semitrailers to be equipped with rear impact guards that
are designed to prevent PCI from a trailer or semitrailer when a
passenger vehicle traveling at 56 km/h (35 mph) makes an impact: (a)
``in which the passenger motor vehicle impacts the center of the rear
of the trailer or semitrailer'' (full overlap with the rear of the
trailer or semitrailer); (b) ``in which 50 percent of the width of the
passenger motor vehicle overlaps the rear of the trailer or
semitrailer''; and (c) ``in which 30 percent of the width of the
passenger motor vehicle overlaps the rear of the trailer or
semitrailer, if the Secretary determines that a revision of [FMVSS Nos.
223 and 224] to address such an impact would meet the requirements and
considerations described in subsections (a) and (b) of section 30111 of
title 49, United States Code'' (i.e., the Safety Act). Section
23011(b)(1)(B) states that the regulations promulgated under Section
23011(b)(1)(A) shall require full compliance not later than two years
after the date on which those regulations are promulgated.
Section 23011(b)(2) of BIL directs the Secretary to conduct
additional research on the design and development of rear impact guards
that can: prevent PCI in cases in which the passenger motor vehicle is
traveling at speeds of up to 65 mph; and that can protect occupants
against severe injury in crashes of passenger vehicles into the rear of
trailers and semitrailers at speeds up to 104.5 km/h (65 mph). Section
23011(b)(3) directs that, not later than 5 years after the date the
regulations under Section 23011(b)(1)(A) are promulgated, the Secretary
shall review and evaluate the need for changes to FMVSS No. 223 and
FMVSS No. 224 in response to advancements in technology and update the
standards accordingly.\14\
---------------------------------------------------------------------------
\14\ There are also provisions relating to the Federal Motor
Carrier Safety Regulations.
---------------------------------------------------------------------------
Section 23011(c)(1)(A) of BIL directs the Secretary to complete,
not later than 1 year after enactment of the Act, additional research
on side underride guards to better understand the overall effectiveness
of the guards. Section 23011(c)(1)(B) requires the Secretary to assess,
among other matters, the feasibility, benefits, and costs of, and any
impacts on intermodal equipment, freight mobility (including port
operations), and freight capacity associated with, installing side
underride guards on new trailers and semitrailers within one year of
enactment of BIL, and if warranted, develop performance standards for
side underride guards. Section 23011(c)(3) also directs the Secretary
to publish the results of the side underride guard assessment specified
in Section 23011(c)(1)(B) within 90 days of completion of the
assessment and provide an opportunity for public comment. It also
directs that, within 90 days from the date the comment period closes,
the Secretary shall submit a report to Congress on the assessment
results, a summary of comments received, and a determination whether
the Secretary intends to develop performance requirements for side
underride guards, including any analysis that led to that
determination.
Section 23011(d) of BIL directs the Secretary to establish an
advisory committee on underride protection to provide advice and
recommendations to the Secretary on safety regulations to reduce
underride crashes and fatalities relating to underride crashes. This
section also provides details on the membership of the advisory
committee, frequency of meetings of the advisory committee, the
Secretary's support to the advisory committee, and details of a
biennial report to Congress that the advisory committee is required to
submit.
Section 23011(e) of BIL directs the Secretary to implement the
recommendations on truck underride guard data collection issued by the
Government Accountability Office
[[Page 42342]]
(GAO) on March 14, 2019,\15\ within 1 year after the date of enactment
of the Act.
---------------------------------------------------------------------------
\15\ GAO Report to Congressional Requestors, ``Truck Underride
Guards--Improved Data Collection, Inspections, and Research
Needed,'' March 14, 2019, (GAO-19-264), https://www.gao.gov/assets/gao-19-264.pdf.
---------------------------------------------------------------------------
3. Implementation of BIL
This final rule fulfills the BIL rulemaking mandate to NHTSA set
forth in Section 23011(b). As directed by Sections 23011(b)(1)(A)(i)
and (ii), this final rule revises FMVSS Nos. 223 and 224 to require
trailers and semitrailers to be equipped with rear impact guards that
prevent passenger compartment intrusion from a trailer or semitrailer
when a passenger motor vehicle traveling at 35 miles per hour makes:
(a) an impact in which the passenger motor vehicle impacts the center
of the rear of the trailer or semitrailer; and (b) an impact in which
50 percent of the width of the passenger motor vehicle overlaps the
rear of the trailer or semitrailer.
This final rule fulfills these BIL rulemaking mandates of Sections
23011(b)(1)(A)(i) and (ii) and achieves, effectively and expeditiously,
the Congressional goal that focuses on improving rear impact guard
performance. The 2015 NPRM proposed to adopt the Canadian quasi-static
test requirements for rear impact guards, which ensure rear impact
guards provide sufficient strength and energy absorption to protect
occupants of compact and subcompact passenger cars impacting the rear
of trailers at 56 km/h (35 mph).\16\ The NPRM reported on crash tests
conducted by IIHS that showed that rear impact guards installed on
trailers that were designed to the proposed requirements were able to
prevent PCI in 35 mph crashes of a passenger vehicle into the rear of
the trailer where: (a) the front end of the passenger vehicle fully
overlapped the rear of the trailer (full overlap crash); and (b) 50
percent of the width of the front end of the passenger vehicle
overlapped the rear of the trailer (50 percent overlap crash). These
data show that trailers and semitrailers equipped with rear impact
guards meeting the requirements of this final rule will have guards
that are designed to prevent PCI when a passenger motor vehicle
traveling at 35 mph impacts the center of the rear of the trailer or
semitrailer, or makes impact in which 50 percent of the width of the
passenger vehicle overlaps the rear of the trailer or semitrailer, in
accordance with BIL.
---------------------------------------------------------------------------
\16\ At the time of enactment of BIL, the agency's December 16,
2015 NPRM upgrading FMVSS No. 223 and FMVSS No. 224 had been
published and DOT's work was close to completion on the final rule.
BIL provides a very short timeframe (1 year) for issuance of a final
rule. The short timeframe is indicative of Congress's intent that a
final rule based on the 2015 NPRM will complete the rulemaking
proceedings specified in Section 23011(b)(1)(A) of the Act.
---------------------------------------------------------------------------
NHTSA's work on this final rule also meets the BIL mandate in
Section 23011(b)(1)(A)(iii). In developing this rule, the agency
considered a requirement that rear impact guards withstand a 56 km/h
(35 mph) crash of a passenger vehicle into the rear of a trailer in
which only 30 percent of the width of the passenger motor vehicle
overlaps the rear of the trailer or semitrailer (30 percent overlap
crash). After analyzing the issue, we determined such a standard would
not meet the requirements and considerations of Sections 30111(a) and
(b) of the Safety Act. Our consideration of this matter is discussed
below.
Sections 30111(a) and 30111(b)
The provision at 49 U.S.C. 30111(a) of the Safety Act authorizes
the Secretary (NHTSA, by delegation) to prescribe Federal motor vehicle
safety standards that are practicable, meet the need for motor vehicle
safety, and are stated in objective terms. ``Motor vehicle safety'' is
defined in the Safety Act 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.'' \17\
---------------------------------------------------------------------------
\17\ 49 U.S.C. 30102(a)(8).
---------------------------------------------------------------------------
The provision at 49 U.S.C. 30111(b) specifies that, when
prescribing such standards, the Secretary must, among other things,
consider all relevant, available motor vehicle safety information,
consider whether a standard is reasonable, practicable, and appropriate
for the types of motor vehicles or motor vehicle equipment for which it
is prescribed, and consider the extent to which the standard will
further the statutory purpose of reducing traffic crashes and
associated deaths and injuries. NHTSA has considered the factors in
Section 30111(b) and concludes that available data do not show that a
standard for a 30 percent overlap crash at 35 mph would be reasonable,
practicable, or appropriate for all the vehicles subject to FMVSS No.
223 and FMVSS No. 224. Accordingly, NHTSA cannot conclude that a
Federal mandate for such a requirement for all trailers is warranted at
this time.
Rear impact guards are designed to absorb energy and prevent PCI by
attaching to substantial structural elements of a trailer or
semitrailer, such as the chassis longitudinal frame rails, by way of
vertical support members. The vertical members of the rear impact guard
usually attach to the longitudinal frame rails so that impact loads are
directly transmitted to the frame rails with minimal or no damage to
the overall trailer structure. The test results from the initial
testing at IIHS reported in the NPRM show that in the 30 percent
overlap crashes, only a small lateral portion of the rear impact guard
(about 22 percent of the guard width) engaged with the front end of the
passenger vehicle. This small lateral portion did not include a
vertical support member of the guard, so when a Chevy Malibu test
vehicle struck this small lateral portion of the guard, the guard
deformed locally and did not prevent PCI. In these initial IIHS crash
tests, only the Manac rear impact guard was able to prevent PCI in the
Chevy Malibu in the 56 km/h (35 mph) full overlap, 50 percent overlap,
and 30 percent overlap crash test conditions. NHTSA believes the Manac
performed this way because, unlike most trailer designs where the
vertical members of the rear impact guard attach directly to the
longitudinal frame rails of the trailer, the vertical members of the
Manac rear impact guard were located further outboard from the location
of the trailer longitudinal frame rails and were attached to a
reinforced floor section of the trailer.
While the more outboard vertical supports of the Manac guard could
withstand the force from the 30 percent low overlap crash of the
Malibu, data suggest the further outboard vertical supports may reduce
guard strength near the center of the horizontal member of the rear
impact guard. In the 56 km/h (35 mph) full overlap crash tests of the
Malibu, the greatest amount of underride (1,350 mm) was in the test
with the Manac trailer. (In contrast, the extent of the underride was
990 mm in the test with the Wabash trailer.) NHTSA found this
observation critical because it indicated that trailers that have the
main vertical supports for the guard more outboard may not perform as
well in full overlap crashes as trailers
that have the vertical supports more inboard. This finding was of key
concern because full and 50 percent overlap crashes are more frequent
than low overlap (30 percent or less) crashes. NHTSA seeks not to amend
FMVSS No. 223 in a manner that could reduce safety in the more frequent
crash conditions.
[[Page 42343]]
Further, data indicate that most fatal light vehicle crashes into
the rear of trailers are at speeds much higher than 56 km/h (35 mph).
The agency is concerned that adopting requirements to mitigate PCI in
30 percent low overlap crashes could result in rear impact guard
designs that may reduce protection against PCI in higher speed crashes.
NHTSA remains concerned about potential negative safety consequences if
a final rule were to adopt requirements that result in moving the
vertical members of rear impact guards more outward laterally to
prevent underride in a 56 km/h (35 mph) 30 percent low overlap crash,
at the expense of protection against higher speed crashes. The agency
believes this issue should be more fully explored before possibly
adopting a 30 percent low overlap requirement.
NHTSA has estimated the benefits and costs of adopting performance
requirements to mitigate underride in low overlap (30 percent or lower
overlap) crashes based on available information. We estimate 0.75 to
1.5 fatalities would be prevented annually if this rule included
requirements to mitigate PCI in 30 percent overlap crashes at 56 km/h
(35 mph) impact speed. (This estimate does not account for the possible
dis-benefits in full and 50 percent offset crashes resulting from a low
overlap requirement, discussed in the paragraph above.) The 0.75 to 1.5
fatalities prevented is based on an estimated 5.8--11.5 annual
fatalities in low overlap crashes into the rear of trailers (crashes
where 30 percent or less of the front end of the impacting vehicle
overlaps the rear of the trailer) and a 13 percent effectiveness of
rear impact guards with 30 percent overlap crash protection in
mitigating fatalities.
To prevent PCI in 30 percent overlap crashes, designs would have to
either: (a) add additional vertical members at the lateral edge of the
rear impact guard that connect to the trailer's transverse floor beam
and strengthen the transverse floor beam of the trailer to withstand
the loads transmitted from these vertical members at the edge of the
guard; or (b) considerably strengthen the rear impact guard member so
it would not deform locally in the 30 percent overlap crash. Both these
approaches would add significant weight to the vehicles because they
involve adding more vertical members, strengthening the floor beams, or
strengthening the guard itself. Additionally, some guard designs may
have restrictions in intermodal operations at loading docks and may not
be practicable for all types of trailers covered by FMVSS No. 224.
NHTSA is required by Section 1 of Executive Order 12866 to conduct
a benefit-cost analysis of any intended regulation.\18\ NHTSA estimates
that the annual minimum and average incremental fleet cost of equipping
all new applicable trailers \19\ with rear impact guards that mitigate
PCI in 30 percent overlap crashes would be $9.9 million and $30.3
million, respectively. The total minimum to average undiscounted
incremental lifetime fuel cost due to increase in weight is estimated
to be $93 million to $130 million. The overall undiscounted cost
increase (material cost and lifetime fuel cost) is a minimum of $103
million to on average $161 million.
---------------------------------------------------------------------------
\18\ ``Significant'' actions are also subject to Section 6's
requirements for a benefit-cost analysis.
\19\ There were 211,807 new trailers sold in 2020, among which
65 percent (137,675 = 211,807 x 0.65) are required to be equipped
with rear impact guards. Among applicable trailers, 28 percent are
already equipped with guards that mitigate PCI in 30 percent overlap
crashes.
---------------------------------------------------------------------------
Using the estimate of 0.75 to 1.5 fatalities that would be
prevented annually, the undiscounted cost per life saved using the
minimum cost estimate ranges from $69 million to $151 million. The
undiscounted cost per life saved using the average cost estimate ranges
from $183 million to $215 million. The Department of Transportation has
recently updated the value of a statistical life, consistent with
Office of Management and Budget (OMB) Circular A-4, to $11.6
million.\20\ Therefore, a requirement for equipping all new applicable
trailers with rear impact guards that mitigate PCI in 30 percent
overlap crashes is not cost-effective.\21\ This indicates that total
costs of such a requirement exceed overall benefits.
---------------------------------------------------------------------------
\20\ For more information on the value of a statistical life,
see a 2021 Office of the Secretary memorandum on the ``Guidance on
Treatment of the Economic Value of a Statistical Life in U.S.
Department of Transportation Analyses--2021 Update.'' https://www.transportation.gov/office-policy/transportation-policy/revised-departmental-guidance-on-valuation-of-a-statistical-life-in-economic-analysis. Circular A-4 provides OMB's guidance to Federal
agencies on the development of a regulatory analysis required under
Section 6 of E.O. 12866.
\21\ Cost-effectiveness represents a measure of the average
monetary cost per unit of change (benefit). In regulatory analyses
for safety policies, cost-effectiveness generally measures the
average estimated change in total costs per unit improvement in
safety (e.g., cost per life saved). A policy alternative can be
considered cost-effective if the estimated cost per unit increase is
less than an appropriate benchmark. For example, a proposed safety
standard could be considered cost-effective if the average cost per
life saved equivalent (i.e., combining lives saved and injuries
avoided, weighted by the relative values of injuries to fatalities)
under the proposed standard were less than the comprehensive
economic cost of a fatality ($11.6 million in 2020 dollars). That
is, the proposed standard would yield safety benefits at a lower
cost than the benchmark value for those benefits.
---------------------------------------------------------------------------
For the above reasons, NHTSA has determined that requirements to
mitigate PCI in a 30 percent overlap crash at 56 km/h (35 mph) would
not meet the requirements of Section 30111(a) of the Safety Act. We
have decided that an FMVSS that requires all covered vehicles (trailers
and semitrailers) to provide rear impact protection in full-frontal, 50
percent overlap, and 30 percent overlap crashes at 56 km/h (35 mph)
impact speed would not be reasonable or practicable for this FMVSS and
would not meet the requirements of Sections 30111(a) and (b) of the
Safety Act for issuance of Federal motor vehicle safety standards.
Accordingly, based on all available data, we have decided that a
Federal mandate for a 30 percent overlap crash for all vehicles subject
to FMVSS Nos. 223 and 224 is not reasonable at this time.
However, while NHTSA cannot conclude that the data and science
currently available for agency decision-making support mandating
installation of a rear impact guard that prevents PCI in all three
overlap conditions (full, 50 percent, and 30 percent overlap) on all
vehicles, the Federal standards act as a floor, not a ceiling, to
establish the minimum level of performance that meet the safety needs
presented by the data. FMVSS are written in terms of minimum
performance requirements for motor vehicles or motor vehicle equipment
to protect the public against unreasonable risk of injury and death in
crashes. Manufacturers have flexibility in design as long as their
products comply with applicable FMVSS. There are rear impact guard
designs in the current trailer and semitrailer market that prevent PCI
in all three crash conditions described in Section 23011(b)(1)(A) of
BIL: (1) full overlap crash, (2) 50 percent overlap crash, and (3) 30
percent overlap crash at 56 km/h impact speed. This final rule does not
preclude these designs from the trailer and semitrailer market, as long
as they meet all requirements of the FMVSS to ensure adequate
protection in (1) and (2), above.
In response to the research mandate in Section 23011(b)(2) of BIL,
NHTSA is conducting additional research on the design and development
of rear impact guards that can prevent underride and protect passengers
in crashes into the rear of trailers at crash speeds up to 104.5 km/h
(65 mph). As part of this research effort, NHTSA will also evaluate
potential cost-effective rear impact guard designs that could improve
protection in the less-frequent 30 percent low overlap crashes while
[[Page 42344]]
enhancing protection in full and 50 percent overlap crashes at higher
speeds.
NHTSA is also working on implementing the other provisions of
Section 23011 of BIL.
c. DOT National Roadway Safety Strategy
This final rule accords with DOT's January 2022 National Roadway
Safety Strategy to address the rising numbers of transportation deaths
occurring on the country's streets, roads, and highways.\22\ At the
core of this strategy is the Department-wide adoption of the Safe
System Approach, which focuses on five key objectives: safer people,
safer roads, safer vehicles, safer speeds, and post-crash care. DOT
announced it will launch new programs, coordinate and improve existing
programs, and adopt a foundational set of principles to guide this
strategy. The National Roadway Safety Strategy includes issuing a final
rule to upgrade existing requirements for rear impact guards on newly
manufactured trailers and semitrailers as a key Departmental action to
enable safer vehicles.\23\
---------------------------------------------------------------------------
\22\ https://www.transportation.gov/sites/dot.gov/files/2022-01/USDOT_National_Roadway_Safety_Strategy_0.pdf.
\23\ Id., p. 31.
---------------------------------------------------------------------------
d. NTSB Recommendation
This final rule accords with an April 3, 2014 recommendation from
the National Transportation Safety Board (NTSB) regarding tractor-
trailer safety (H-14-004). NTSB recommended that NHTSA revise FMVSS
Nos. 223 and 224 to ensure that newly manufactured trailers over 4,536
kg (10,000 lb) GVWR provide adequate protection of passenger vehicle
occupants from fatalities and serious injuries resulting from full-
width and offset trailer rear impacts. In its recommendation, NTSB made
favorable reference to IIHS's petition for rulemaking (the petition is
discussed below).
e. Impacts of This Rulemaking
NHTSA has issued a Final Regulatory Evaluation (FRE) that analyzes
the potential impacts of this final rule. The FRE is available in the
docket for this rule.\24\
---------------------------------------------------------------------------
\24\ The FRE may be obtained by downloading it or by contacting
Docket Management at the address or telephone number provided at the
beginning of this document.
---------------------------------------------------------------------------
NHTSA estimates that 94 percent of new trailers sold in the U.S.
subject to FMVSS Nos. 223 and 224 are already designed to comply with
CMVSS No. 223. The agency estimates that about 0.56 lives and 3.5
serious injuries would be saved annually by requiring all trailers
covered by Standard No. 224 to be equipped with CMVSS No. 223 compliant
guards. The undiscounted equivalent lives saved are 1.4 per year.
Considering that 94 percent of applicable trailers already have
CMVSS compliant guards, the annual average incremental fleet cost of
equipping all applicable trailers with CMVSS No. 223 rear impact guards
is estimated to be $2.10 million in 2020 dollars. In addition, the
added weight of 48.9 pounds per vehicle would result in an estimated
annual fleet fuel cost of approximately $4.43 million and $5.59 million
discounted at 7% and 3%, respectively. As such, the total incremental
cost would range from $6.54 million to $7.69 million discounted at 7%
and 3%, respectively, as shown in Table 1.
Table 1--Cost of the Final Rule With Average Increase in Weight
[In millions of 2020 dollars]
----------------------------------------------------------------------------------------------------------------
Discount rate Undiscounted 3% 7%
----------------------------------------------------------------------------------------------------------------
Material *...................................................... $2.10 $2.10 $2.10
Fuel............................................................ 6.90 5.59 4.43
-----------------------------------------------
Total....................................................... 9.00 7.69 6.54
----------------------------------------------------------------------------------------------------------------
* Material costs are not discounted since they occur at the time of purchase
The estimated equivalent lives saved (ELS) ranges from 0.90 lives
to 1.14 lives discounted at 7% and 3%, respectively. The cost of the
final rule is the regulatory cost and ranges from $6.54 million to
$7.69 million discounted at 7% and 3%, respectively. The cost per ELS
ranges from $6.77 million to $7.25 million discounted at 3% and 7%,
respectively, as shown in Table 2 below.
Table 2--Cost per Equivalent Lives Saved
[In millions of 2020 dollars]
----------------------------------------------------------------------------------------------------------------
Discount rate Undiscounted 3% 7%
----------------------------------------------------------------------------------------------------------------
Total cost...................................................... $9.00 $7.69 $6.54
Equivalent lives saved.......................................... 1.40 1.14 0.90
Cost per ELS.................................................... $6.42 $6.77 $7.25
----------------------------------------------------------------------------------------------------------------
The net benefit of the final rule is the difference between the
comprehensive benefit and the total cost. The estimated net benefit
ranges from $4.36 million to $6.04 million discounted at 7% and 3%,
respectively, as shown in Table 3 below.
Table 3--Net Benefits
[In millions of 2020 dollars]
----------------------------------------------------------------------------------------------------------------
Discounted rate Undiscounted 3% 7%
----------------------------------------------------------------------------------------------------------------
Comprehensive benefit........................................... $16.96 $13.73 $10.90
[[Page 42345]]
Total cost...................................................... 9.00 7.69 6.54
-----------------------------------------------
Net benefit................................................. 7.96 6.04 4.36
----------------------------------------------------------------------------------------------------------------
Table 4 summarizes the total costs, comprehensive benefits, and net
benefits for both 3 and 7 percent discount rates.
Table 4--Costs and Benefits
[In millions of 2020 dollars]
--------------------------------------------------------------------------------------------------------------------------------------------------------
Comprehensive
Discount rate Material cost Fuel cost Total costs benefits Net benefits
--------------------------------------------------------------------------------------------------------------------------------------------------------
3%....................................................... $2.10 $5.59 $7.69 $13.73 $6.04
7%....................................................... 2.10 4.43 6.54 10.90 4.36
--------------------------------------------------------------------------------------------------------------------------------------------------------
f. No Significant Changes to the NPRM
After carefully reviewing the comments, NHTSA is adopting most of
the proposed rule, while clarifying the wording that attachment
hardware remain intact during quasi-static load tests in FMVSS No. 223.
NHTSA is also making a technical correction to the citation referenced
in the definition of ``temporary living quarters'' in FMVSS No. 224.
II. Background
a. Current Requirements
FMVSS No. 223 requires rear impact guards to meet the strength
requirements and energy absorption requirements of the standard at
certain specified test locations. Test locations P1, P2, and P3 are
depicted in Figure 1. Test location P1 is 3/8th of the width of the
horizontal member from the centerline on either side of the horizontal
member. Test location P2 is at the centerline of the horizontal member.
Test location P3 is 355 millimeters (mm) (14 inches) to 635 mm (25
inches) from the horizontal member centerline. The strength tests are
conducted separately from the energy absorption test.
The strength requirements (S5.2.1) specify that the guard must
resist the following force levels without deflecting by more than 125
mm (4.9 inches):
50,000 Newtons (N) (or 50 kiloNewtons (kN)) at P1 on
either the left or the right side of the guard;
50,000 N at P2; and,
100,000 N at P3 on either the left or the right side of
the guard.
In the strength test, the force is applied by a force application
device (rectangular rigid steel solid face of 203 mm x 203 mm and
thickness of 25 mm) until the force level is exceeded or until the
displacement device is displaced at least 125 mm, whichever occurs
first.
The energy absorption requirements (S5.2.2) specify that a guard
(other than a hydraulic guard) must absorb, by plastic deformation,
within the first 125 mm of deflection at least 5,650 Joules (J) of
energy at each test location P3. In the test procedure, force is
applied to the guard using the force application device until
displacement of the device has reached 125 mm, recording the value of
force at least 10 times per 25 mm of displacement. The force is then
reduced until the guard no longer offers resistance to the force
application device. A force versus deflection diagram is plotted with
deflection (measured displacement of the force application device)
along the abscissa (x-axis) and the measured force along the ordinate
(y-axis), as shown in Figure 2, and the energy absorbed by the guard is
determined by calculating the shaded area bounded by the curve in the
diagram.
[[Page 42346]]
[GRAPHIC] [TIFF OMITTED] TR15JY22.000
[GRAPHIC] [TIFF OMITTED] TR15JY22.001
FMVSS No. 224 requires each vehicle to be equipped with a rear
impact guard certified to FMVSS No. 223 and attached to the vehicle's
chassis in accordance with installation instructions that the guard
manufacturer provided pursuant to FMVSS No. 223. Standard No. 224
specifies that the ground clearance (vertical distance of the bottom of
the horizontal member from ground) of the rear impact guard be no more
than 560 mm (22 inches) and
[[Page 42347]]
located not more than 305 mm (12 inches) forward of the rear extremity
of the trailer and extend laterally to within 100 mm (4 inches) of each
side of the vehicle as shown in Figure 3.
[GRAPHIC] [TIFF OMITTED] TR15JY22.002
b. Petitions
IIHS requested, among other things, that NHTSA upgrade rear impact
guard strength requirements, reduce the number of exempted vehicles to
provide occupant protection in higher speed crashes and move the P1
test location farther outboard to improve crash protection in low
overlap conditions. IIHS requested that NHTSA require attachment
hardware to remain intact for the duration of the quasi-static test or
until reaching a force threshold ``much higher than that required for
the guard itself.'' \25\ The Karth/TSC petition asked that NHTSA
improve the safety of rear impact guards. In later correspondence with
NHTSA, these petitioners state that if FMVSS No. 223 were amended to be
equivalent to CMVSS No. 223, injuries and fatalities could be
avoided.\26\ We provided a detailed discussion of the petitions, and
our response to them, in the NPRM preceding this final rule.
---------------------------------------------------------------------------
\25\ After submitting its petition in 2011, IIHS conducted
additional crash tests of a 2010 Chevrolet Malibu at 56 km/h (35
mph) into eight guard/trailers: A 2011 Wabash, 2012 Manac, 2012
Stoughton, 2013 Great Dane, 2012-2013 Hyundai, 2013 Strick, 2013
Utility, and 2013 Vanguard, all of which were certified as complying
with CMVSS No. 223. NHTSA included a summary of the IIHS tests in
the December 16, 2015 NPRM. 80 FR 78452-78460. All eight trailers
were able to prevent PCI with 100 percent overlap. In the tests with
50 percent overlap, apart from the 2013 Vanguard trailer, the
remaining seven guard/trailers were able to prevent PCI. The rear
impact guard on the 2013 Vanguard failed at the attachments where
the bolts sheared off during the crash resulting in PCI.
\26\ NHTSA responded to the Karth/TSC petition by issuing two
separate notices, one of which was the NPRM preceding this final
rule (July 10, 2014; 79 FR 39362). The other was an advanced notice
of proposed rulemaking (ANPRM) published on July 23, 2015 (80 FR
43663) pertaining to the agency's estimated benefits and costs of
rear impact guards for single unit trucks (SUTs) and of an
alternative of increasing the conspicuity of SUTs through
conspicuity tape. FMVSS No. 108, ``Lamps, reflective devices, and
associated equipment,'' requires retroreflective material on the
rear and sides of trailers to improve the conspicuity of the
vehicles to other motorists as a means of preventing underride
crashes. The ANPRM analyzed estimated benefits and costs of
requiring similar tape for SUTs. NHTSA will follow up on the ANPRM
in a document separate from this final rule.
---------------------------------------------------------------------------
c. Summary of Proposed Changes
NHTSA proposed to adopt requirements of Transport Canada's standard
for rear impact guards, which require rear impact guards to provide
sufficient strength and energy absorption to protect occupants of
compact and subcompact passenger cars impacting the rear of trailers at
56 km/h (35 mph). The NPRM proposed the following specific changes to
FMVSS Nos. 223 and 224.\27\
---------------------------------------------------------------------------
\27\ In addition, we proposed a few housekeeping amendments. We
proposed to add back ``low chassis vehicles'' into the list of
vehicles excluded from FMVSS No. 224 in the applicability section
(S3). The vehicles were excluded from the standard in the January
24, 1996 final rule establishing FMVSS No. 224 (61 FR 2035) but were
inadvertently omitted from S3 when S3 was amended by a final rule
responding to petitions for reconsideration (63 FR 3654, January 26,
1998). We also proposed to correct typographical errors in the
standards. We make these changes in this final rule.
---------------------------------------------------------------------------
Performance Requirements
NHTSA proposed that the loading and performance requirements of
FMVSS No. 223 adopt the specifications in CMVSS No. 223. Specifically:
The NPRM proposed to amend FMVSS No. 223 to require rear
impact guards (except as noted below) to resist a uniform distributed
load of 350,000 N without deflecting more than 125 mm, while absorbing
at least 20,000 J of
[[Page 42348]]
energy by plastic deformation within the first 125 mm of deflection;
Alternatively, guards may resist a minimum uniform
distributed load of 700,000 N without deflecting 125 mm.
In accordance with CMVSS No. 223, we proposed to require
that rear impact guards be required to maintain a ground clearance
after the energy absorption test not exceeding 560 mm. For rear impact
guards with strength exceeding 700,000 N in the uniform distributed
load test, the post-test ground clearance is measured after the uniform
distributed load test. A definition of ``ground clearance'' would be
added to FMVSS No. 223.
We proposed that FMVSS No. 223 require that any portion of
the rear impact guard and attachments not separate from their mounting
structure after completion of FMVSS No. 223's uniform distributed
loading test and the energy absorption test.
Definition of ``Rear Extremity'' \28\
---------------------------------------------------------------------------
\28\ We sought to further harmonize FMVSS No. 224 with CMVSS No.
223.
---------------------------------------------------------------------------
We proposed to replace the current definition of ``rear extremity''
in FMVSS No. 224 with that specified in CMVSS No. 223. The change was
intended to ensure that aerodynamic fairings are located within a
certain safe zone at the rear of the trailer. Aerodynamic fairings on
the rear of trailers, also known as ``boat tails,'' are rear-mounted
panels on trailers that reduce aerodynamic drag and fuel consumption.
The safety concern about boat tails is that they generally extend
beyond the rear extremity of trailers and thus can negate the crash
protection provided by rear impact guards. That is, there is a
possibility that a boat tail can protrude so far rearward that it can
intrude into the passenger compartment in a crash and cause injury,
notwithstanding the presence of an upgraded rear impact guard.
III. Summary of Comments
NHTSA received fifty (50) comments on the NPRM.\29\ Ten comments
were received from the three petitioners (IIHS, Ms. Marianne Karth
(with her husband Mr. Jerry Karth), and the TSC), one comment was
received from the National Transportation Safety Board (NTSB), six
comments were received from industry associations (the Recreation
Vehicle Industry Association (RVIA), the Truck Trailer Manufacturers
Association (TTMA), the American Trucking Association, Inc. (ATA), the
National Truck Equipment Association (NTEA), and the National Propane
Gas Association (NPGA)), two comments were received from trailer
manufacturers (Strick Trailers, LLC (Strick) and the Wabash National
Corporation (Wabash)), seven comments were received from engineers (the
Mechanical Engineering Underride Design Group at Virginia Tech (VT
Group), Seven Hills Engineering, LLC (Seven Hills), Batzer Engineering,
Inc. (Batzer), and Mr. Aaron Kiefer), two comments were received from
attorneys (Mr. D.J. Young, III and Mr. Andy Young), ten comments were
received from advocacy groups (e.g., Underride Network, Road Safe
America (RSA), and Advocates for Highway and Auto Safety (AHAS)), and
twelve comments were received from individual members of the general
public.
Comments were generally in favor of upgrading rear impact guard
performance. The petitioners, NTSB, engineers, attorneys, advocacy
groups, and individuals from the general public argued, however, for
increasing the stringency of FMVSS Nos. 223 and 224 beyond what was
proposed in the NPRM. These groups also suggested that NHTSA take other
actions suggested in the initial IIHS and Karth/TSC petitions that
NHTSA had not proposed in the NPRM. The industry associations and
trailer manufacturers were generally in favor of the proposed rule and
opposed further changes to it. Comments also covered issues such as
alternative guard designs, NHTSA's benefit-cost analysis, the proposed
lead time, retrofitting issues, and side and front guards.
IV. Response to Comments on the Proposed Amendments
a. General Strength and Energy Absorption Requirements
In the NPRM, NHTSA proposed to harmonize FMVSS No. 223's test and
performance requirements to those specified in CMVSS No. 223 by
replacing the current quasi-static point load test at the P3 location
with a uniform distributed load test of 350,000 N. Under this test,
NHTSA proposed that the rear impact guard must resist the 350,000 N
load without deflecting more than 125 mm, absorb at least 20,000 J of
energy within 125 mm of guard deflection, and have a ground clearance
not exceeding 560 mm after completion of the test.
Comments Received
Commenters supported upgrading FMVSS No. 223's requirements as
proposed, but most also suggested that NHTSA issue requirements more
stringent than those proposed. Multiple commenters argued that, because
93 percent of trailers already comply with CMVSS No. 223 according to
the NPRM, the proposed requirements would make little tangible
difference and not prevent the underride injuries that are still
occurring. The Underride Network (Network) stated that NHTSA's proposal
would only ``upgrade the standard as basically existed in 1996,''
without going further to include technological improvements made for
rear impact guards. Wabash, on the other hand, suggested that even
though most new trailers currently adhere to CMVSS No. 223, there is
still a benefit to the proposed requirements. Wabash argued that
adopting the proposed requirements would both mandate that the
remaining portion of the new trailer fleet adopt upgraded rear impact
guards and allow NHTSA to take enforcement action against any company
that fails to install upgraded rear impact guards.
Some commenters also urged NHTSA not to adopt a proposal that only
provides protection against underride at impact speeds up to 56 km/h
(35 mph), stating that these crashes only represent a fraction of all
rear underride crashes. These commenters remarked that NHTSA should do
more to provide protections for underride crashes that occur at greater
speeds. Some commenters suggested specific requirements that they
believed NHTSA should adopt instead of those proposed in the NPRM.
Network requested that the quasi-static loading tests use a force of
200 (kN) at the P1 and P2 test locations and 100 kN at the P3 test
location. Mr. Kiefer suggested that rear impact guards should be quasi-
statically tested to ``at least 80% of reasonable crash pulse
loadings.'' Mr. Karth referenced what he called a ``new Australian/New
Zealand proposed rule'' and asked NHTSA to use that as a basis for its
standards. According to Mr. Karth, the Australian/New Zealand proposed
rule states that current vehicle crashworthiness technology can protect
passengers in collisions with a deformable barrier at impact speeds
around 64 km/h (40 mph) and that energy absorbing rear impact guards
could reduce injury at higher speeds. Ms. Karth echoed this point,
stating that adopting the Australian/New Zealand proposed rule would
save more lives than adopting standards based on CMVSS No. 223. These
and all other relevant comments are address below.
Agency Response
After reviewing the comments, NHTSA is adopting the strength and
energy absorption standards as proposed in the NPRM. NHTSA recognizes
that many commenters have asked NHTSA to require rear impact
[[Page 42349]]
guards to provide protection against underride at impact speeds beyond
56 km/h (35 mph). As discussed below, NHTSA is researching this area.
However, based on available data, the agency does not believe that such
increased requirements are reasonable or practicable at this time. Rear
impact guards are meant to work with passenger vehicle safety features
to protect occupants of the vehicle during a collision. For these
passenger vehicle safety features to activate, the passenger vehicle
must collide with the rear impact guard, and this collision itself
poses risks to passenger safety. Currently, FMVSS No. 208 requires
passenger vehicles to provide protection in front collisions at speeds
up to 56 km/h (35 mph). Even if a rear impact guard were to prevent PCI
at impact speeds above 56 km/h (35 mph), a passenger vehicle in
compliance with FMVSS No. 208 may not be able to protect the vehicle's
occupants at speeds above 56 km/h (35 mph) in a collision with a rear
impact guard. Commenters did not provide data showing current passenger
vehicle safety features would prevent injuries in underride collisions
above 56 km/h (35 mph). Accordingly, NHTSA concludes it is appropriate
for this final rule to align the requirements in FMVSS Nos. 223 and 224
with those in FMVSS No. 208 and CMVSS No. 223, as proposed in the NPRM.
This final rule adopts those proposed requirements.
Further, the 56 km/h (35 mph) crash speed accords with Section
23011(b)(1)(A) of BIL. BIL states that, not later than 1 year after the
date of enactment of the Act, the Secretary shall promulgate
regulations that revise FMVSS No. 223 and FMVSS No. 224 to require new
trailers and semitrailers to be equipped with rear impact guards that
are designed to prevent PCI from a trailer or semitrailer when a
passenger vehicle traveling at 56 km/h (35 mph) makes an impact into
the center of the rear of the trailer or semitrailer and in which 50
percent of the width of the passenger motor vehicle overlaps the rear
of the trailer or semitrailer. This final rule's adoption of the NPRM's
proposed test speed meets the BIL statutory mandate within the
timeframe directed by the Act, and meets the requirements for FMVSSs
required by the Safety Act.
In response to the research mandate in Section 23011(b)(2) of BIL,
NHTSA is conducting additional research on the design and development
of rear impact guards that can prevent underride and protect passengers
in crashes into the rear of trailers at crash speeds up to 104.5 km/h
(65 mph). After the completion of this research, NHTSA will evaluate
potential requirements for rear impact guards for preventing underride
and protecting occupants at impact speeds greater than 35 mph.
Commenters also referred to guard designs and recommendations
developed by third parties that claim to offer greater protection at
higher impact speeds than guards currently in use. There is no evidence
that any have been finalized, implemented, and proven feasible for
commercial use. The Intelliguard/Impact Project, a design source cited
by Mr. Karth, explicitly stated, ``The guard needs, however, further
optimization to become commercially feasible.''
Network asked NHTSA to test rear impact guards ``at real world
speeds,'' arguing that the Federal Highway Administration (FHWA) tests
crash attenuators at 100 km/h (62.2 mph) and that NHTSA should crash
test rear impact guards at similar speeds. In response, NHTSA notes,
first, that it did not propose to test at highway speeds in the NPRM
and believes this request may be outside the scope of this rulemaking.
Further, NHTSA does not believe that Network's comparison of rear
impact guards and FHWA roadside crash attenuators is appropriate.
Roadside crash attenuators are stationary barriers placed alongside
roads that are designed to absorb a colliding vehicle's energy and
safely redirect the vehicle or bring it to a stop. A typical crash
attenuator system is 50 feet long. In contrast, rear impact guards are
structures attached to the rear of mobile trailers to mitigate
underride of the impacting vehicle. Roadside crash attenuators,
therefore, are designed for a different environment than a rear impact
guard, have different performance requirements,\30\ and have fewer
operational and practical restrictions on their size and weight versus
rear impact guards. Similar performance for truck rear impact guards at
highway speeds has not been shown to be technically feasible.
---------------------------------------------------------------------------
\30\ Roadside crash barriers, guardrails and other roadside
safety features installed along U.S. highways undergo
crashworthiness testing in accordance with the American Association
of State Highway and Transportation Officials (AASHTO) Manual for
Assessing Safety Hardware (MASH). The AASHTO MASH was updated in
2016 and includes vehicle crash testing at 6 different test levels
(TL-1 to TL-6) based on the type of crash attenuator, type of road,
and traffic patterns.
TL-1: Cars and trucks--31 mph
TL-2: Cars and trucks--44 mph
TL-3: Cars and trucks--62 mph
TL-4: Cars, trucks, and single unit trucks--62 mph and
56 mph respectively
TL-5: Cars, trucks, and tractor trailers--62 and 50 mph
respectively
TL-6: Cars, trucks, and tractor tank trailers--62 and
50 mph respectively
---------------------------------------------------------------------------
In terms of specific standards suggested by commenters, these
commenters unfortunately did not provide sufficient information to
warrant modifying the proposed requirements. Commenters did not provide
data showing the extent to which guards compliant with these various
standards are superior to the Canadian guards. NHTSA notes that the
``Australian/New Zealand proposed rule'' referenced by Mr. and Ms.
Karth is not a regulatory requirement, but rather is an industry design
guideline created by Standards Australia and Standards New Zealand.
These guidelines do not provide information to warrant modifying
NHTSA's proposal. In terms of rear impact guards performing at impact
speeds above 56 km/h (35 mph), the guidelines only conjecture that
guards could be developed that reduce serious injury to vehicle
occupants at speeds above 70 km/h; they do not provide instructions on
how to design such guards or data regarding practicability,
effectiveness or performance. Not enough is known about these standards
to assess the need for them or whether adopting them would meet the
requirements of the Safety Act.
b. Alternative Guard Designs
Based on tests conducted by Transport Canada showing that a CMVSS
No. 223 compliant guard was able to prevent PCI in 56 km/h (35 mph)
vehicle impacts into the rear of trailers with 100 percent and 50
percent overlap, NHTSA proposed to adopt CMVSS No. 223's strength and
energy absorption requirements.
Comments Received
NHTSA received many comments arguing that the proposed standards
were inadequate because rear impact guards generally meet them already.
Advocates and IIHS referred to a 2011 Wabash guard, involved in the
tests conducted by IIHS, to argue that the guard exceeded the CMVSS
force requirements by more than 70 percent in quasi-static tests. Other
commenters also mentioned that they believed it possible to design a
rear impact guard that could provide protection for rear underride
crashes at speeds greater than 56 km/h (35 mph), several pointing to
testing conducted by third parties to support these claims. Network and
Mr. Karth stated that the Monash University Accident Research Centre
(MUARC) tested energy-absorbing guards to 75 km/h (47 mph) in the early
1990s. They also claimed that the Impact Project had
[[Page 42350]]
tested energy-absorbing guards to 40 mph with computer modeling showing
that the guards might be able to perform at 50 mph or more. Mr. Young
noted that the VC-Compat project is ``currently proposing and
recommending stronger rear impact guards to meet higher speeds.''
Other commenters stated that they personally were either developing
or had seen rear impact guards that were improvements over guards
meeting the current and proposed standards. Mr. Karth pointed to a
design developed by the VT Group which, he claimed, ``shows promise of
greatly improving the current standard at a reasonable cost.'' Mr.
Kiefer stated that he had developed a rear guard system that will
exceed the proposed standards. Mr. Karth stated that he was told by a
Mr. Sicking that he ``can design a system which will prevent underride
guard failures'' that occur ``at much higher speeds.''
Agency Response
NHTSA has evaluated the data from IIHS and other research groups
provided by the commenters and cannot agree that the information forms
a technical basis for modifying the proposed requirements. Advocates
and IIHS argued that rear impact guards could provide protection at
speeds higher than 56 km/h (35 mph) because the Wabash guard exceeded
CMVSS No. 223 force requirements by ``more than 70 percent'' in tests
conducted by IIHS. Our analysis of the comment, however, determined
that IIHS's tests were different than, and not comparable to, the CMVSS
No. 223 tests. IIHS conducted a point load test at P3, which is very
different than the uniform distributed load specified in CMVSS No. 223
and this final rule.\31\ As the tests are not comparable, it cannot be
concluded that the Wabash guard exceeded the CMVSS No. 223 force
requirement by more than 70 percent. Additionally, the data do not show
that the guard would provide better crash protection in dynamic impacts
above 56 km/h (35 mph). I.e., the data did not link IIHS's quasi-static
test values to evidence of actual dynamic crash performance at higher
impact speeds.
---------------------------------------------------------------------------
\31\ A point load test applies a concentrated load to a focused
point. The uniform distributed load tests specified in CMVSS No. 223
and this final rule apply the test load over a wider area.
---------------------------------------------------------------------------
Section 1 of E.O. 12866 requires agencies to base their decisions
on the best reasonably available scientific, technical, economic, and
other information on the need for, and consequences of, the intended
regulation. In accordance with the E.O., this final rule will complete
the upgrade of Standard No. 223 to the Canadian standard as proposed,
as it is based on the best information reasonably available at this
time. However, while the commenters' information does not form a
comprehensive or complete basis for modifying the rear impact guard
requirements above that which was proposed, NHTSA is continuing to
research this area in response to BIL. Pursuant to the research mandate
in BIL Section 23011(b)(2), NHTSA is conducting additional research on
the design and development of rear impact guards that prevent underride
and protect passengers in crashes into the rear of trailers at crash
speeds up to 104.5 km/h (65 mph). The results of this research and
other information will provide more data and other information that can
guide decisions about updating the rear impact guard standards at a
future date.
In response to commenters, NHTSA also reviewed guard designs and
recommendations developed by third parties (MUARC, VT group, Aaron
Kiefer, Sickling) that several commenters believed could offer greater
protection at higher impact speeds than rear impact guards currently in
use.\32\ As these guards have not been finalized, implemented, proven
effective or shown feasible for commercial use in the industry, the
agency could not reasonably include requirements for these guards in
FMVSS Nos. 223 and 224 at this time.\33\ Also, not enough is known
about the rationale for various specifications of the experimental
guards. For instance, MUARC, an organization favorably cited by many
commenters, stated \34\ that it had designed a guard which prevented
PCI in a 75 km/h (46 mph) centered impact test and recommended that
guards be able to absorb 50 kiloJoules (kJ) and quasi-static forces of
200 kN at the P1 location, 100 kN at the P2 location, and 200 kN at the
P3 location. It is unclear how MUARC developed these quasi-static test
recommendations and how these recommendations relate to dynamic crash
test performance. Further, MUARC's 50 kJ and the 100 kJ energy
absorption recommendation does not specify the degree of deflection at
which the guard must meet this energy absorption requirement, and the
experimental guard designed by MUARC never advanced beyond the proof-
of-concept phase.\35\ There is no information on the long term
durability and costs of a MUARC guard since it is not available for
purchase and installation, nor can NHTSA know if such a guard can be
feasibly and effectively used for different types of trailers, such as
those with unique geometry.
---------------------------------------------------------------------------
\32\ The petitioners, the attorney commenters, UN, AHAS, Seven
Hills, Aaron Kiefer, and Andy Young cited design testing conducted
by the Intelliguard/Impact Project, the VT Group, VC-Compat, MUARC,
and Aaron Kiefer to support claims that guards with greater crash
protection at higher impact velocities are feasible.
\33\ Section 23011 (b)(1) of BIL requires a regulation revising
FMVSS No. 223 and No. 224 not later than 1 (one) year after the
November 15, 2021, date of enactment of the Act.
\34\ MUARC discussed its research in a 2001 submission to the
International Technical Conference on the Enhanced Safety of
Vehicles. Rechnitzer, G., Powell, C., and Seyer, K., ``Performance
Criteria, Design, and Crash Tests of Rear Underride Barriers for
Heavy Vehicles,'' Proceedings of the Seventeenth International
Technical Conference on the Enhanced Safety of Vehicles, Paper No.
218, https://www-esv.nhtsa.dot.gov/Proceedings/17/00189.pdf.
\35\ Federal regulations in Australia for rear impact guards are
similar to those in Europe and Australia. The MUARC recommendations
are not used as performance requirements in Australian Federal
standards and there are no manufacturers in Australia voluntarily
designing their guards to meet the MUARC recommendations.
---------------------------------------------------------------------------
NHTSA has the same concerns with the experimental guards described
by the Impact Project, the VC-Compat project, the VT Group, Mr. Kiefer,
and Mr. Sicking. Commenters did not provide information that the guards
are effective at providing protection at impact speeds beyond 56 km/h
(35 mph) and failed to provide a verifiable relationship between the
results of the dynamic crash tests and quasi-static specifications that
NHTSA relies on in FMVSS No. 223. In the absence of such data, there is
insufficient information supporting using these experimental guards to
form the requirements for FMVSS Nos. 223 and 224. As discussed above,
however, NHTSA will continue researching guard performance in higher
speed crashes in response to BIL and anticipates obtaining more
comprehensive information about the performance and other features of
potential guards designed for higher speed impacts.
c. 700 kN Energy Absorption Test Option
The NPRM proposed to include an option from CMVSS No. 223
permitting a rear impact guard not to meet the energy absorption
requirements of the uniform distributed load test detailed above if it
is able to resist 700,000 N (700 kN) of force without deflecting more
than 125 mm and maintain a ground clearance of 560 mm after completion
of the test. NHTSA noted in the NPRM that it did not believe that
guards will likely be manufactured to this test but sought comment on
[[Page 42351]]
whether this alternative testing option should be included in FMVSS No.
223.
Comments Received
Commenters were divided in their support of the 700 kN test option.
TTMA stated in support that keeping this as an option would allow TTMA
members to retain needed flexibility. Batzer asserted in support that,
since passenger vehicles have improved their energy absorbing
characteristics since the 1996 final rule, NHTSA does not need to
require that rear impact guards meet an energy absorption requirement
as long as the guards can provide a certain level of resistance force.
Network stated that this option ``might make sense,'' but also stated
that rear impact guards must be able to absorb a minimum of 50 kJ, and
preferred that guards be able to absorb 100 kJ. Ms. Wood agreed that
rear impact guards must be able to absorb at least 50 kJ. The VT Group
disagreed with including the 700 kN test, stating that doing so would
afford manufacturers the ability to omit a horizontal member from a
rear impact guard. The VT Group claimed that without a horizontally
distributing structure, ``a minor impact more closely resembles a pole
strike.''
Agency Response
NHTSA agrees with TTMA and Batzer and believes it appropriate to
adopt the 700 kN test option. Network and the VT Group expressed
reservations about the option, but they did not provide data or other
evidence demonstrating that this option would be detrimental to safety.
They did not provide any further information supporting the request for
a 50 kJ or 100 kJ energy absorption requirement, nor did they explain
how the 700 kN test option would allow manufacturers to omit a
horizontal member. FMVSS No. 223 S5.1 specifies that the vertical
height of the horizontal member must be at least 100 mm and FMVSS No.
224 S5.1 specifies geometric requirements for the rear impact guard
that remain unchanged by this test option.
Transport Canada developed the 700 kN test option based on rigid
barrier crash test results suggesting that a resistance to a uniform
load of at least 700 kN would help ensure that the rear impact guard
will stay in place and prevent underride in an impact with a passenger
car at impact speeds of 56 km/h (35 mph).\36\ NHTSA concludes that the
data from Transport Canada, cited in the NPRM, demonstrate the
effectiveness and feasibility of this option in preventing underride at
35 mph.\37\
---------------------------------------------------------------------------
\36\ Canada Gazette Part II, Vol. 138, No. 20, 2004-10-06, p.
1349.
\37\ Boucher, D., ``Heavy Trailer rear underride crash tests
performed with passenger vehicles,'' Technical Memorandum No. TMVS-
0001, Transport Canada, Road Safety and Motor Vehicle Regulation
Directorate, July 2000.
---------------------------------------------------------------------------
d. Ground Clearance
NHTSA proposed maintaining the current ground clearance requirement
of 560 mm (22 inches) (S5.1.2, FMVSS No. 224) but also proposed
updating FMVSS No. 223 to require rear impact guards to maintain a
ground clearance of 560 mm (22 inches) after completion of the load
application during the energy absorption test. Due to deformation that
may occur upon loading, NHTSA noted that this requirement may
correspond to an initial ground clearance on the trailer that is
actually less than 560 mm (22 inches).
Comments Received
Many commenters suggested lowering the ground clearance
requirement. These commenters generally argued that rear impact guards
must align with the height of car bumpers and since NHTSA mandates that
passenger car bumpers be 16 to 20 inches (406.4 to 508 mm) off the
ground, NHTSA must lower the ground clearance requirement to this
level. The VT Group stated that NHTSA's bumper standards in ``49 CFR
581 requires a light vehicle bumper height of 16 to 20'' inches and
that lowering ground clearance to this level ``could ensure proper
initial engagement with light vehicle safety systems.'' Batzer
similarly stated that the most effectively designed rear impact guard
``would engage the bumper of the striking passenger vehicle.''
Commenters also suggested that, because the average guard height for
trailers currently is 18 inches (457.2 mm), there is no need for NHTSA
to allow for a higher ground clearance. Mr. D.J. Young, III and Mr.
Andy Young stated that technology exists that can raise or lower rear
impact guards, and therefore NHTSA should not be concerned that a lower
ground clearance requirement could result in a rear impact guard
scrapping or snagging along the ground.
Agency Response
NHTSA proposed amending FMVSS No. 223 to require that, after the
energy absorption test where the guard is displaced 125 mm, the rear
impact guard has to maintain a ground clearance not exceeding 560 mm
(22 inches) but did not propose to alter the 560 mm (22 inches) ground
clearance requirement in FMVSS No. 224. The NPRM explicitly stated that
NHTSA was denying the request made by petitioners to lower the ground
clearance requirement and NHTSA did not propose such a change in the
NPRM. The suggestions to lower the ground clearance requirement are
thus not within the scope of this rulemaking. Further, NHTSA included
in the NPRM its rationale for denying the request to lower the ground
clearance requirement, and, after reviewing the comments and other
information, NHTSA has not changed its position on these points. In the
interest of discussion, NHTSA will briefly repeat its reasoning
here.\38\
---------------------------------------------------------------------------
\38\ NHTSA's entire rationale is detailed in the NPRM for this
final rule. See 80 FR 78424-78426.
---------------------------------------------------------------------------
Comments stating that NHTSA should modify the ground clearance
requirement to align with NHTSA's bumper standard (49 CFR part 581)
misunderstood the purpose of the bumper standard and repeat a concern
to which NHTSA responded in the 1996 final rule establishing FMVSS Nos.
223 and 224.\39\ The bumper standard under 49 CFR part 581 is designed
to prevent damage to a car body and its safety related equipment in
impacts of 3.2 km/h (2 mph) across the full width of the bumper and 1.6
km/h (1 mph) on the corners. The bumper standard is not, in other
words, intended to provide occupant protection from crashes at injury-
causing impact speeds. That function is instead performed by the
vehicle's chassis energy-management design and its energy-absorbing
frame rails, which rely on the engagement of the vehicle's major
structural components with the rear impact guard.
---------------------------------------------------------------------------
\39\ See final rule, 61 FR 2004, 2017; January 24, 1996.
---------------------------------------------------------------------------
Nor is it the case that the major structural components of vehicles
have been so lowered as to necessitate lowering the ground clearance
requirement. To the contrary, the height of the top of the engine block
appears to have increased since NHTSA promulgated the 1996 final rule
that required the 560 mm (22 inches) ground clearance. Using engine
block height as a suitable metric to represent a major structural
element of the striking vehicle that would engage the rear impact
guard, when NHTSA issued the 1996 final rule, NHTSA determined the
typical height of the top of the engine block as between 660 and 790 mm
(26 and 31 inches). 61 FR 2017. In contrast, as discussed in the 2015
NPRM for this final rule, data show that the current height of the top
of the engine block is between 739 mm (29.1 inches) and 1300 mm (51.2
inches), with an average height of 889 mm (35 inches) (80 FR
[[Page 42352]]
78425). Thus, passenger vehicle designs have changed in years since the
establishment of the 560 mm (22 inches) ground clearance specification
such that there is a greater likelihood of engagement of their major
structural components with the rear impact guard.
Further, NHTSA is concerned that some trailers may face operational
issues if NHTSA lowered the ground clearance requirement. Trailers may
snag and scrape at loading docks and steep railroad crossings,
resulting in damage to the guard, if guards were required to be lower
to the ground. The commenters advocating for a lower ground clearance
requirement provided no data to show that this possible risk can be
overcome or is offset by any potential benefits. Similarly, NHTSA does
not believe it is appropriate to lower the ground clearance requirement
and then force operators involved in intermodal operations to possess
trailers with rear impact guards that can be raised and lowered. Doing
so would unnecessarily burden the industry and raise costs, and
commenters have not identified any associated benefits that would
justify this decision.
e. Requiring Attachment Hardware To Remain Intact
The NPRM focused on ensuring the attachment hardware of the rear
impact guard remained intact in the quasi-static loading tests. It
proposed to prohibit the complete separation of any portion of the
guard and the guard attachments from its mounting structure after
completion of the quasi-static uniform distributed load test (proposed
S5.2.1). NHTSA stated in the NPRM (80 FR at 48429) that it was
interpreting ```any portion of the guard and the guard attachment
completely separating from its mounting structure' to mean the
condition where any member of the guard becomes detached from any other
member of the guard or from the trailer such that the joint is no
longer mechanically bound together.'' The agency further stated that it
would not consider a partial separation of the members at a joint where
there is still some degree of mechanical connection between the members
as a ``complete separation.'' Id. NHTSA sought comment on this proposed
performance criterion and whether its objectivity could be improved by,
e.g., specifying the percentage of fasteners or welds that remain
intact during the test.
Comments Received
Commenters had different views regarding the proposed requirement
that attachment hardware remain attached throughout the quasi-static
test. Notably, commenters in favor of such a requirement still asked
NHTSA to refine the language used in the regulatory text. The NTSB
stated that it supported developing performance criteria to determine
objectively the degree of separation that may significantly reduce rear
impact guard performance, but the commenter did not provide information
on what the criteria should be. IIHS stated that the standard should
require rear impact guards to withstand the quasi-static load tests
without any separation between the guard and guard attachments rather
than adopt the criterion of complete separation that NHTSA proposed.
IIHS believed that NHTSA's language in the preamble, stating that the
agency would consider partial separation acceptable as long as there
was still some degree of mechanical connection between the guard's
members, was vague. Due to this perceived ambiguity, IIHS questioned
whether NHTSA would consider a joint where 3 of 4 bolts were sheared to
constitute a partial separation.
The TTMA, on the other hand, expressed concerns with making the
standard overly complicated in trying to make it more objective,
stating that setting specific requirements for numbers of welds or
fasteners to remain intact ``would unnecessarily complicate the
standard compared to the Canadian equivalent, and could preclude the
use of designs with components that may be designed to shear or tear as
part of an energy mitigation strategy.'' Seven Hills remarked that
TTMA's concerns could be alleviated by modifying the design of rear
impact guards.
Agency Response
NHTSA agrees with the comments that FMVSS No. 223 should require
attachment hardware to remain attached during the quasi-static load
test. However, NHTSA does not agree with IIHS's specific suggestion of
a requirement that there be no separation at any point. Guards may be
designed to have attachment hardware shear away from the guard during
impact to absorb the impact energy. The agency does not find it
necessary to prohibit these kinds of guards if they meet the criterion
discussed below.
While NHTSA requested comments on an objective criterion that would
keep guards from separating from their attachment hardware (other than
by prohibiting a ``complete separation''), the agency did not receive
any data or bases to aid NHTSA on this issue. NHTSA agrees with
commenters, though, that the language the agency used in describing the
requirement in the NPRM could be clearer. NHTSA proposed in S5.2.1 that
a tested guard must resist the force levels specified in S5.2.1(a)
through (c) without deflecting by more than 125 mm and ``without
complete separation of any portion of the guard and guard attachments
from its mounting structure.'' This final rule replaces the phrase
``without complete separation of any portion of the guard and guard
attachments from its mounting structure'' in proposed S5.2.1 and
S5.2.2(a)(1) with the phrase ``without eliminating any load path that
existed before the test was initiated.'' ``Load path'' is a standard
engineering term. The agency is defining ``load path'' to mean a route
of force transmission from the horizontal member of the guard to the
chassis.\40\
---------------------------------------------------------------------------
\40\ ``Chassis'' is defined in FMVSS No. 223, S4, as the load
supporting frame structure of a motor vehicle.
---------------------------------------------------------------------------
Load paths represent how forces applied to the guard will transmit
through the guard to the chassis based on the geometry of the guard.
For the purposes of FMVSS No. 223, NHTSA will determine load paths by
visual inspection prior to conducting the quasi-static load tests.
NHTSA will assess whether any load paths are eliminated after any force
applied during the test using the force application device is removed.
``Eliminating a load path'' means that a load path designed to transmit
force from the horizontal member of the rear impact guard to the
chassis, can no longer transmit the force.
If two or more members in the load path are joined using multiple
bolts, NHTSA will not consider each bolt to be an individual load path.
For instance, if the vertical member of a rear impact guard was
attached to the horizontal member by four bolts, NHTSA would not
consider the load path to have been eliminated if one, two, or three of
the bolts sheared off or otherwise became disconnected during testing.
On the other hand, if all four bolts sheared off, or otherwise became
disconnected, the agency would consider this to constitute an
eliminated load path, even if the guard's members remained in contact
due to friction or the structural integrity of another portion of the
guard. To use another example, if two members in a load path are
connected by a single weld and if the weld developed one or more
discontinuous cracks during testing, NHTSA would not consider this to
constitute an eliminated load path. If, however, a continuous crack
developed during testing along the entire length of the weld holding
the two members together, this would constitute an eliminated load path
as a route of force
[[Page 42353]]
transmission would have been eliminated even if the members remained in
contact through friction or the structural integrity of another portion
of the guard. When all mechanical connection along a route of force
transmission from the horizontal member of the guard to the chassis is
lost, we would consider this to be an eliminated load path. If the two
members in a load path were connected by two welds and a continuous
crack developed along the entire length of only one of the welds, this
would not constitute an eliminated load path.
f. Definition of Rear Extremity
The NPRM proposed replacing the current definition of ``rear
extremity'' in FMVSS No. 224 with the definition from CMVSS No. 223.
NHTSA proposed this change to account for aerodynamic fairings, also
known as ``boat tails,'' which are rear-mounted panels that reduce
aerodynamic drag and fuel consumption. The proposed change to the
definition of ``rear extremity'' was meant to ensure that aerodynamic
fairings would be placed where, in a collision, they would not
jeopardize the safety of occupants in vehicles striking the rear of the
trailer.
Comments Received
Network, TTMA, and NTSB all supported NHTSA's proposed change. The
VT Group and Batzer raised concerns that aerodynamic fairings could
pierce windshields in instances of partial underride and pose an
impalement hazard. Batzer further suggested that NHTSA require every
trailer manufacturer and/or user with a non-standard end profile to do
a formal engineering analysis of their equipment to document that they
have considered the safety implications of their design.
Agency Response
After reviewing the comments on this issue, NHTSA agrees with
commenters supporting the proposal. The proposed definition for ``rear
extremity'' is based on the Canadian definition, which Transport Canada
arrived at after extensive research into aerodynamic fairings. While
commenters raised concerns over impalement risks, aerodynamic fairings
are typically lightweight structures and no commenter provided evidence
showing a risk of vehicle occupant impalement by such fairings. NHTSA
will continue to monitor rear impact collisions and revisit the
definition if necessary. Requiring trailer manufacturers to do a formal
engineering analysis on aerodynamic fairings, as Batzer suggested, is
beyond the scope of the proposal.
g. Low Chassis Vehicle Correction
FMVSS No. 224 excludes several types of trailers from application
of the standard (S3). As noted in the NPRM, low chassis vehicles \41\
were originally excluded from FMVSS No. 224 in a 1996 final rule
establishing the standard (61 FR 2035) but NHTSA inadvertently did not
list the vehicles in S3 in a 1998 amendment that responded to petitions
for reconsideration (63 FR 3654). The agency proposed to correct the
omission and list low chassis vehicles back in S3.
---------------------------------------------------------------------------
\41\ A ``low chassis vehicle'' is defined in FMVSS No. 224 as a
trailer or semitrailer having a chassis that extends behind the
rearmost point of the rearmost tires and a lower rear surface that
meets the configuration requirements of S5.1.1 through 5.1.3 of
Standard No. 224.
---------------------------------------------------------------------------
Although the NPRM did not propose to expand the applicability of
FMVSS No. 224, NHTSA received many comments urging NHTSA to apply the
standard to vehicles now excluded from it. We discuss these comments in
Section V below. As to correcting S3 to add low chassis vehicles back
into S3, NHTSA did not receive any comments opposed to the correction.
Accordingly, this final rule corrects S3 as proposed.
h. Technical Correction
The NPRM's proposed regulatory text for FMVSS No. 224 included
restated current text in S3 that excluded vehicles with temporary
living quarters ``as defined in 49 CFR 529.2.'' RVIA commented on this
proposed wording, stating that the NPRM's reference to ``temporary
living quarters as defined in 49 CFR 529.2'' was an incorrect
reference. RVIA suggested that the definition of temporary living
quarters should point to 49 CFR 523.2.
RVIA is correct that the NPRM's reference to 49 CFR 529.2 as
providing a definition for temporary living quarters was erroneous. The
regulations at 49 CFR 529.2 do not include any definition for temporary
living quarters. The preamble for the 1996 final rule properly referred
to 49 CFR 523.2 (61 FR 2022), but the regulatory text for the 1996
final rule mistakenly referenced 49 CFR 529.2 (61 FR 2035). NHTSA is
taking this opportunity to make a technical correction to FMVSS No. 224
and make clear that the definition of temporary living quarters is
defined in 49 CFR 523.2.
V. Response to Comments on Issues Not Proposed in the NPRM
NHTSA received a number of comments on aspects of FMVSS No. 223 and
224 that the agency did not propose to change. Although these comments
were beyond the scope of the rulemaking, we discuss them here to
further our dialogue in this area.
a. Vehicles Excluded From FMVSS No. 224
FMVSS No. 224 (S3) excludes pole trailers, pulpwood trailers, road
construction controlled horizontal discharge trailers, special purpose
vehicles, wheels back vehicles, or temporary living quarters (S3).
NHTSA did not propose to remove any of these exclusions. We evaluated
the exclusions when we were drafting the NPRM and decided not to change
them (80 FR 78426-78428). The decision was based on our analysis of
data provided by the 2013 UMTRI Study.\42\
---------------------------------------------------------------------------
\42\ As discussed earlier in this preamble, the 2013 UMTRI Study
collected supplemental data to that collected in TIFA for the years
2008 and 2009. The supplemental survey data included details of the
truck rear extremity, whether a rear impact guard was required,
relative impact speed of the crash, and the extent of underride.
---------------------------------------------------------------------------
Comments Received
A number of commenters disagreed with NHTSA's continued exclusion
of various vehicles. Commenters raised the most concerns about the
exclusions for single unit trucks (SUTs) \43\ and wheels back trailers.
---------------------------------------------------------------------------
\43\ SUTs are trucks with a GVWR greater than 4,536 kg (10,000
lb) with no trailer. They are primarily straight trucks, in which
the engine, cab, drive train, and cargo area are mounted on one
chassis. As SUTs are not trailers, they are not subject to FMVSS
Nos. 223 and 224.
---------------------------------------------------------------------------
SUTs. VT Group believed that regulating SUTs was necessary, citing
data NHTSA included in the NPRM that, of the 121 light vehicle fatal
crashes annually that result in PCI, 19 percent occur in impacts with
SUTs without guards. NTSB argued that the adverse effects of SUT
crashes have been underestimated in the past ``because these trucks are
frequently misclassified and thus undercounted.'' Based on previous
research findings portraying underride as underreported in
FARS,44 45 Ms. Karth stated that NHTSA's analysis for SUTs
was skewed by what she believed to be inaccurate, underreported
information about PCI from underride. Mr. Young commented that further
consideration of ways to engineer guards for SUTs ``is warranted
[[Page 42354]]
despite the difficulties associated with those vehicles.''
---------------------------------------------------------------------------
\44\ Braver, E.R.; Mitter, E.L.; Lund, A.K.; Cammisa, M.X.;
Powell, M.R.; and Early, N. 1998. A photograph-based study of the
incidence of fatal truck underride crashes in Indiana. Accident
Analysis and Prevention, vol. 30, no. 2, pp. 235-243.
\45\ Blower D and Campbell K. 1999. Underride in Rear-End Fatal
Truck Crashes, The University of Michigan Transportation Research
Institute, 1999.
---------------------------------------------------------------------------
Agency Response. Because of prior research findings raising the
possibility of underreporting of underride in FARS, NHTSA initiated
research in 2010 with UMTRI that formed the basis of the 2013 UMTRI
Study. The purpose of this research was to gather accurate data on the
rear geometry of SUTs and trailers, the configuration of rear impact
guards on SUTs and trailers, and the incidence and extent of underride
and fatalities in rear impacts with SUTs and trailers. UMTRI collected
the supplemental information as part of the TIFA survey for the years
2008 and 2009.46 47 These data enabled NHTSA to obtain
national estimates of rear impact crashes into heavy vehicles that
resulted in PCI. Using information derived by reviewing police crash
reports,\48\ UMTRI estimated the relative speed of fatal light vehicle
crashes into the rear of SUTs and trailers. Because of the detailed
analysis and the supplemental information collected for each crash, the
2013 UMTRI Study forms the most comprehensive and valid data set
available to inform the agency regarding crashes involving SUTs and
trailers and the incidence and extent of underride.
---------------------------------------------------------------------------
\46\ Analysis of Rear Underride in Fatal Truck Crashes, 2008,
DOT HS 811 652, August 2012, infra.
\47\ Heavy-Vehicle Crash Data Collection and Analysis to
Characterize Rear and Side Underride and Front Override in Fatal
Truck Crashes, DOT HS 811 725, March 2013, infra.
\48\ Information included police estimates of travel speed,
crash narrative, crash diagram, and witness statements. The impact
speed was estimated from the travel speed, skid distance, and an
estimate of the coefficient of friction.
---------------------------------------------------------------------------
Regarding NTSB assertions that SUT crashes are underestimated in
FARS because trucks are frequently misclassified, and with respect to
Ms. Karth's comment that underride and PCI are underreported in FARS,
NHTSA did not use FARS data in developing this rulemaking and instead
used TIFA data for the years 2008 and 2009 with supplemental
information reported in the 2013 UMTRI Study.\49\ As explained earlier
in this preamble, the TIFA database is supplemental to FARS, and has
improved the accuracy of FARS data on fatal large truck crashes. It
provides more detailed information than in FARS on the involved large
trucks, motor carriers, and sequence of events.\50\ The TIFA and 2013
UMTRI Study comprise the best scientific data on underride crashes.
Thus, this rulemaking used the most accurate estimate of SUT crashes,
as determined by the best available scientific data in the area, and we
do not believe SUT crashes were underestimated.
---------------------------------------------------------------------------
\49\ Heavy-Vehicle Crash Data Collection and Analysis to
Characterize Rear and Side Underride and Front Override in Fatal
Truck Crashes, DOT HS 811 725, March 2013.
\50\ NTSB stated in a 2013 safety study, ``The TIFA database
provides more accurate classifications of large truck vehicle body
types by using information from the vehicle identification number
(VIN) and by collecting additional data for all fatal large truck
crashes.'' Crashes involving single-unit trucks that resulted in
fatalities and injuries, National Transportation Safety Board Safety
Study, NTSB/SS-13/01, PB2013-106637, June 2013.
---------------------------------------------------------------------------
With further regard to whether NHTSA's data underreported
underride, we believe that the data appear to include some crashes that
did not actually result in underride. In the 2013 UMTRI Study, the
extent of underride was estimated in terms of the amount of the
striking vehicle that went under the rear of the struck vehicle and/or
the extent of deformation or intrusion of the striking vehicle. The
categories were ``no underride,'' ``less than halfway up the hood,''
``more than halfway but short of the base of the windshield,'' and ``at
or beyond the base of the windshield.'' NHTSA believes it is most
relevant for this rulemaking to consider the relevant crashes to be as
an underride that resulted in PCI beyond the base of the windshield.
However, since the 2013 UMTRI Study determined the extent of underride
by the extent of deformation and intrusion of the vehicle, there were a
number of TIFA cases involving large vans and large pickups that did
not actually underride the truck or trailer, but that had sustained PCI
because of the high speed of the crash and/or because of the very short
front end of the vehicle. Because these large striking vehicles did not
underride the struck vehicle, NHTSA's interpretation in the NPRM of PCI
from the 2013 UMTRI Study potentially overestimated the occurrence of
PCI due to underride. We believe, in other words, that NHTSA's analysis
using data in the 2013 UMTRI Study potentially overestimated PCI due to
underride.
NHTSA responded to the Karth/TSC petition by publishing two
separate notices.\51\ NHTSA first published an advance notice of
proposed rulemaking (ANPRM) on July 23, 2015, pertaining to issues
concerning rear impact guards for single unit trucks (SUTs), including
whether to apply FMVSS No. 224 to the vehicle type and whether to apply
FMVSS No. 108's requirements for conspicuity tape.\52\ Second, NHTSA
published the NPRM preceding this final rule upgrading rear impact
guards on December 16, 2015. Comments relating to the application of
FMVSS No. 224 to SUTs will be addressed in a follow up document to the
2015 ANPRM and will not be addressed in this final rule.
---------------------------------------------------------------------------
\51\ 79 FR 39362.
\52\ 80 FR 43663.
---------------------------------------------------------------------------
Wheels Back Vehicles. TSC opposed FMVSS No. 224's exclusion of
wheels back trailers. Similarly, Advocates suggested that the NPRM's
discussion of the involvement of wheels back vehicles in fatal crashes
did not support the agency's conclusion that excluding wheels back
trailers ``may not have significant safety consequences.'' \53\ The
commenter criticized the 2013 UMTRI Study that NHTSA relied on, stating
that the sort of speed estimates used in the study are notoriously
inaccurate and that data generated in the TIFA database frequently
depend on unreliable telephone interviews and post-crash interviews.
IIHS similarly objected to NHTSA's use of the supplemented TIFA data,
stating that UMTRI had previously cautioned against defining degrees of
underride, and that NHTSA's use of estimated crash speeds was
speculative. IIHS also noted that the 2008-2009 TIFA survey found that
one-half of wheels back trailers involved in fatal crashes were
equipped with rear impact guards, which IIHS believed raised concerns
``about the validity of the comparisons of underride severity by
trailer type.'' Network stated that, as modern cars require flat
surfaces to interact with vehicle safety systems, the safety systems
will not engage when a vehicle impacts the rear of wheels back
trailers, as tires on a wheels back trailer present an uneven surface
hazard. Network also stated that agricultural trucks in North Dakota
have shown a net benefit from adding rear impact guards.
---------------------------------------------------------------------------
\53\ The NPRM provided data that wheels back vehicles account
for 20 percent of fatal light vehicle impacts into the rear of
trailers, and that 16 percent of fatal light vehicle impacts into
wheels back trailers resulted in PCI.
---------------------------------------------------------------------------
Agency Response. NHTSA has considered the comments but does not
believe available data support applying FMVSS No. 224 to wheels back
trailers.\54\ In the UMTRI study, crashes into the rear of wheels back
trailers accounted for 6 percent of all fatal light vehicle crashes
into the rear of trucks and trailers that resulted in PCI. Detailed
analysis of the fatal light vehicle impacts into the rear of wheels
back trailers that resulted in PCI in 2009 indicated that the crashes
were generally at very high impact speeds that are considered
unsurvivable. In all these crashes, it is unlikely that a rear impact
guard designed to CMVSS No. 223 would have prevented PCI into these
vehicles. A rear impact guard
[[Page 42355]]
would not have prevented these fatalities.\55\
---------------------------------------------------------------------------
\54\ 80 FR 78427-78428.
\55\ 80 FR 78428.
---------------------------------------------------------------------------
NHTSA has also analyzed comments criticizing the 2013 UMTRI Study
as applied to wheels back trailers and believes that the data in the
study are sound. The UMTRI data were enhanced specifically for trailer
rear impact analysis and the study contains enriched data specific to
impact performance. The 2013 UMTRI Study \56\ was based on enhanced
Trucks in Fatal Accidents (TIFA) data for the years 2008 and 2009. The
enhanced data included supplemental information, collected as part of
the NHTSA funded study, on the rear-end configuration of SUTs and
trailers and the incidence and nature of underride and associated
fatalities in crashes into the rear of SUTs and trailers, and an
estimate of the relative velocity of the light vehicle crash.\57\ The
data from the 2013 UMTRI Study comprise the most accurate and complete
dataset available for evaluating the incidence of underride and are
appropriate for use for evaluating underride incidences in light
vehicle crashes into the rear of wheels back trailers. While commenters
made general statements that the variables used in this data set are
unreliable, none presented alternative data that they considered more
accurate.
---------------------------------------------------------------------------
\56\ Heavy-Vehicle Crash Data Collection and Analysis to
Characterize Rear and Side Underride and Front Override in Fatal
Truck Crashes, DOT HS 811 725, March 2013, supra. Also available at
https://www.nhtsa.gov/sites/nhtsa.gov/files/811725.pdf.
\57\ UMTRI estimated the relative speed of fatal light vehicle
crashes into the rear of SUTs and trailers using all available
information, including police estimates of travel speed, crash
narrative, crash diagram, and witness statements. The impact speed
was estimated from the travel speed, skid distance, and an estimate
of the coefficient of friction. Relative velocity was computed as
the resultant of the difference in the trailer (truck) velocity and
the striking vehicle velocity and could only be estimated for about
30 percent of light vehicle fatal crashes into the rear of trailers
and SUTs.
---------------------------------------------------------------------------
NHTSA also does not agree with IIHS that the presence of wheels
back trailers with rear impact guards in the 2013 UMTRI Study raises
doubts about NHTSA's conclusion there is an absence of a safety need
for the guards. First, while IIHS references data from the TIFA data
sets for 2008-2009 to claim that half of wheels back trailers involved
in a fatal crash were equipped with rear impact guards, the data do not
provide information on the guards equipped or the need for a guard. The
data sets do not record if any of the guards were original equipment or
were even compliant to a standard such as FMVSS No. 223. The presence
of a rear impact guard that lacks sufficient strength and energy
absorption characteristics specified in FMVSS No. 223 would not
mitigate PCI in light vehicles at impact speeds 30 mph or lower.
Further, IIHS implies that the guards prevented underride rather
than the wheels of wheels back trailers, but does not provide
information to substantiate the claim that the guards had prevented
underride rather than the wheels of the trailer. IIHS provided no data
to suggest this interaction with the guard versus the wheels is
occurring. In the 1996 final rule that established FMVSS No. 224, NHTSA
determined that ``a fixed rear axle with the tires mounted within 305
mm [12 inches] . . . of the vehicle's rear extremity constitutes an
adequate substitute for a rear impact protection guard from the
standpoint of preventing PCI.'' \58\ This is a straightforward
conclusion and no information has been provided to change our
conclusion on this issue. We similarly do not find Network's statement
that vehicle crashworthiness safety systems will not engage during
impacts with the rear of wheels back trailers to be supported by any
evidence. Network did not support its assertion, and it is contradicted
by the results of past dynamic crash tests of light vehicles into the
rear of wheels back trailers.\59\
---------------------------------------------------------------------------
\58\ 61 FR 2024.
\59\ Id. Two crash tests involving wheels back trailers were
conducted in support of the 1996 final rule. For these wheels back
trailers, the rear tires were located about 100 to 205 mm (4 to 8
in) forward of the rear extremity of the trailer. In each test, in
an offset crash in which a Chevrolet Impala struck the tires and in
a centric crash in which a VW Rabbit struck the axle and other
components between the tires, PCI was prevented at about 56 kph (35
mph).
---------------------------------------------------------------------------
Horizontal discharge trailers: NHTSA disagrees with TTMA and NTEA's
views that there should be a blanket exclusion of end-dump trailers
from FMVSS No. 224. When we modified FMVSS No. 224 to exclude road
construction controlled horizontal discharge trailers (S4), we received
comments similar to those sent by TTMA and NTEA that requested us to
exclude gravity feed end-dump trailers.\60\ In response, NHTSA noted
that end-dump trailers are versatile vehicles that may not necessarily
interact with equipment in a way that necessitates an exception, as
many fall under the exception for wheels back trailers and many may
also be able to accommodate a rear impact guard. For these reasons, we
explained that we preferred to review the necessity of exempting end-
dump trailers on a case-by-case basis in the context of temporary
exemptions under 49 CFR part 555. NHTSA continues to believe this is
the most appropriate approach to these vehicles.
---------------------------------------------------------------------------
\60\ See 69 FR 67663, 67666.
---------------------------------------------------------------------------
Trailers with lift gates: In response to Mr. Young's comment that
trailers with lift gates should not be excluded from the standard,
trailers with lift gates are not currently excluded from FMVSS No. 224,
and NHTSA did not propose any changes in this regard.\61\ Trailers with
certain kinds of lift gates may fall under the definition of ``special
purpose vehicle,'' but the comment did not refer to such vehicles.
---------------------------------------------------------------------------
\61\ See 69 FR 64495, 64497.
---------------------------------------------------------------------------
b. Testing on a Trailer Rather Than a Fixture
FMVSS No. 223 currently provides that NHTSA may test a rear impact
guard when attached, per manufacturer's instructions, to either a rigid
test fixture or to a complete trailer, at the guard manufacturer's
option. As discussed in the NPRM, NHTSA denied the request from the
petitioners to remove the option of testing on a rigid test fixture.
The agency determined that the two tests are essentially equivalent and
that requiring that guards be tested when attached to the trailer could
be a significant cost burden to small trailer manufacturers.
Comments Received
Many commenters expressed a preference to NHTSA's testing guards
only when attached to a complete trailer. Ms. Karth and Network stated
that rear impact guards and the trailers to which they are attached are
a system and that compliance testing should be conducted with the guard
attached to the trailers and/or a portion of the trailer that includes
all structures to which the guard attaches. Batzer believed that
testing rear impact guards on the trailer on which they will be mounted
``would produce more confidence in the design.'' IIHS and Advocates
stated that testing on rigid test fixtures disregarded the fact that
crash tests with rear impact guards attached to trailers resulted in
deformation to the trailer. IIHS stated that allowing rear impact
guards to be tested when attached to a rigid fixture rather than to an
actual trailer is ``insufficient to guarantee underride prevention''
because a guard certified to meet the standards of CMVSS No. 223 may be
attached to a trailer structure that does not have the demonstrated
capability to resist the same force level. IIHS claimed that the
relatively weaker structure of the trailer may deform during a crash,
leaving ``open the possibility that guards will be attached
[[Page 42356]]
to trailer structures that are too weak to withstand the forces of a
crash, in which case the strength of the guard itself is irrelevant.''
Advocates also believed that ``significant issues with the performance
of the guard and the attachment system would not be detected'' if the
guard was tested on a rigid test fixture. Some commenters also argued
that the higher burdens to small manufacturers ``is an insufficient
justification.'' TSC stated that NHTSA should require testing on a
trailer as it reflects a real-world scenario ``even if the process is
more costly.''
Agency Response
We considered the suggestion to remove the option for fixture
testing when we evaluated the petitions and ultimately concluded not to
include it in the proposed rule. Many of the commenters raise points
NHTSA discussed in the NPRM and points NHTSA had discussed in the
original 1996 final rule. In the 1996 final rule, NHTSA explained that,
even though testing on a trailer is desirable ``because there is
nothing more `appropriately configured' for guard mounting on the
actual trailer'' and because such testing also tests the structural
integrity of the trailer chassis, the agency's data demonstrated that
rear impact guards tested on rigid test fixtures performed similarly to
their performance on an actual trailer.\62\ NHTSA reiterated this point
in the NPRM for this final rule, and commenters did not provide any new
information to suggest that testing on a rigid test fixture is no
longer acceptable. NHTSA concludes that a guard shown to be compliant
when tested on a rigid test fixture will perform to the same benchmark
when attached to a trailer.
---------------------------------------------------------------------------
\62\ See 61 FR 2008, 2014. NHTSA's testing showed that the
maximum force measured in quasi-static tests of rear impact guards
attached to a fixture is similar to the maximum force generated in
dynamic crash tests with the rear impact guard installed on a
trailer. Additionally, rear impact guards that were only ten percent
stronger than the minimum level of strength necessary to pass
quasistatic test requirements performed adequately in dynamic tests
with the guard installed on a trailer.
---------------------------------------------------------------------------
NHTSA stated its view that a rear impact guard attached to a rigid
test fixture would not have a trailer to absorb a portion of the load
so the severity of the fixture test might be higher than a trailer
test. IIHS and Advocates seemed to argue the opposite, stating that
testing on rigid test fixtures disregarded the fact that crash tests
with rear impact guards attached to trailers resulted in deformation to
the trailer. NHTSA cannot conclude that trailer deformation itself
indicates that the total resistance of a guard-attachment-trailer
system is lower than that of the guard alone on a rigid test fixture.
The trailer structure may have deformed because it offered resistance
to the dynamic loads. As stated in the NPRM, testing on a rigid test
fixture has an advantage over trailer testing in its potential to show
that the guard is capable of resisting all loads and absorbing all the
energy.
The commenters did not provide information showing that requiring
each rear impact guard be tested on a trailer would offset the
significant costs of doing so, especially for small trailer
manufacturers with low sales volumes. As noted in the NPRM, if small
manufacturers were to test the rear impact guard on the trailer, this
testing could involve sacrificing what could constitute a substantial
part of their overall trailer production. NHTSA does not believe there
is a safety basis justifying these impacts on these manufacturers.
Finally, NHTSA emphasizes the test specifications in the FMVSS
reflect how NHTSA will perform tests to evaluate compliance; they do
not limit how manufacturers certify compliance. Inserting a requirement
into FMVSS No. 223 specifying how manufacturers can certify their own
compliance, as suggested by Batzer and VT Group, is not in accordance
with the purpose and structure of the FMVSS.
c. Low Overlap Crash Performance
Both petitioners IIHS and TSC/Karth requested that NHTSA take steps
to prevent underride in low overlap crashes (crashes with 30 percent
overlap or less of the impacting vehicle with the trailer rear).\63\
IIHS's petition asked NHTSA to evaluate relocating the quasi-static
point load test at the P1 location further outboard toward the end of
the guard horizontal member so that guards are tested for strength
further outboard. IIHS suggested that, based on its interpretation of
the crash tests of the 2010 Chevrolet Malibu into the rear of the 2011
Wabash trailer, doing so would provide underride protection to full, 50
percent, and 30 percent overlap crashes.\64\
---------------------------------------------------------------------------
\63\ Overlap is the percentage of the light vehicle width that
interacts with the rear of the trailer in a collision. Offset means
the centerline of the light vehicle is not aligned with the
centerline of the trailer. Other organizations may use low overlap
or offset to refer to different specified amounts of overlap.
\64\ In IIHS's 30 percent overlap crash test with the Chevrolet
Malibu, the front end of the Malibu only contacted the portion of
the rear impact guard lateral of the vertical support member.
---------------------------------------------------------------------------
NHTSA reviewed the requests in the petitions but did not propose to
move the P1 location further outboard as a part of this rulemaking. The
requests were not supported by sufficient information, as the
petitioners did not explain why moving the P1 location further outboard
would improve guard performance in low overlap crashes.
NHTSA determined that the performance of rear impact guards in
crashes other than low overlap should be enhanced before turning to
performance specific to low overlap crashes. We analyzed the data
collected in the 2013 UMTRI Study and found that underride crashes of
30 percent overlap or less represented a smaller portion of the rear
underride fatality problem than non-low overlap crashes. We decided to
focus the NPRM on crashes other than low overlap because those were the
more prevalent fatal crashes.
The data do not show that improving low overlap crash performance
would improve non-offset crash performance. In fact, data indicate a
potential negative consequence. NHTSA expressed a concern in the NPRM
about a potential risk that bolstering performance in a 30 percent
overlap crash might degrade protection in 50 and 100 percent overlap
crashes. The Manac rear impact guard features vertical supports towards
the lateral edge of the trailer. While this guard was able to prevent
PCI in the 56 km/h (35 mph) 30 percent overlap condition during IIHS's
crash tests, in IIHS's 56 km/h (35 mph) full overlap crash test, the
Manac guard had the greatest amount of deformation (1,350 mm) of any
guard. NHTSA was concerned that these data indicated that rear impact
guards designed like the Manac, with the main vertical supports for the
guard more outboard, may not perform as well compared to other guards
in full overlap crashes at crash speeds at or greater than 56 km/h (35
mph).
To summarize, data indicated that: (a) full and 50 percent overlap
crashes are more frequent than 30 percent overlap crashes; (b) most
fatal light vehicle impacts into the rear of trailers are at speeds
greater than 56 km/h (35 mph); and, (c) improving performance against
low overlap crashes could reduce performance of the guard in full and
50 percent overlap crashes. Given those factors, we decided not to take
an approach in this rulemaking that would improve guard performance in
a 30 percent overlap crash but that could lessen protection in 50 and
100 percent overlap crashes at higher speeds (speeds higher than the 35
mph speed on which the amended FMVSS No. 223 would be based).
[[Page 42357]]
Comments and Agency Response
Several commenters disagreed with NHTSA's decision to refrain from
pursuing rulemaking on low overlap crashes. Some commenters pointed to
existing guards (e.g., the Manac guard) that they stressed provided
protection against crashes with low overlap. Some disagreed with
NHTSA's concern that such a guard might not perform as well in crashes
with full or 50 percent overlap at crash speeds greater than 56 km/h
(35 mph). Seven Hills stated that the extent of underride seen in the
full overlap crash test with the Manac guard was due to the Chevrolet
Malibu fitting ``just between both uprights contacting only the
horizontal bar,'' and that this scenario ``represents an extremely
small fraction of possible crash scenarios.'' IIHS argued that the
Manac design performed well and that it is not the only possible guard
design; IIHS said it tested a 2015 Vanguard design that was also able
to prevent severe underride at 30 percent overlap.\65\ Conversely,
Wabash concurred that the design of the Manac guard reduced protection
in full overlap conditions.
---------------------------------------------------------------------------
\65\ In 2017, IIHS introduced the TOUGHGUARD award for trailers
that mitigate PCI in a 56 km/h (35 mph) crash of a Chevrolet Malibu
into the rear of the trailer in all three overlap conditions (full,
50 percent, and 30 percent). IIHS awarded the TOUGHGUARD to nine
North American trailer manufacturers that offer this feature on at
least some trailers.
---------------------------------------------------------------------------
Agency Response
Several commenters argued that fatal low overlap crashes occurred
more frequently than stated by NHTSA. IIHS believed that the data
underlying NHTSA's finding that 40 percent of light vehicle impacts
into the rear end of trucks and trailers in fatal crashes were offset
crashes were collected ``during phone interviews with someone who was
familiar with each crash but may not have been at the crash scene'' and
``took place 1-2 years after the crash.'' Advocates remarked that TIFA
survey data ``is known to consist of notoriously suspect crash data and
analysis.'' In response, NHTSA does not agree that the agency did not
accurately calculate the prevalence of low overlap crashes. The 2013
UMTRI Study forms the most scientific, comprehensive and valid data set
available to inform the agency and safety community on this issue.
IIHS referred to its 2010 study of passenger vehicle crashes into
the rear of trailers and semitrailers in the Large Truck Crash
Causation Study (LTCCS) to argue that, ``guard deformation or complete
failure was frequent and most commonly due to weak attachments,
buckling of the trailer chassis, or bending of the lateral end of the
guard under narrow overlap loading.'' \66\ IIHS noted that there were
30 LTCCS cases in the study involving trailers with guards that met the
FMVSS No. 224 geometric requirements and among these 30 cases, 30
percent (n=9) were crashes in which less than half of the passenger
vehicle overlapped the trailer.
---------------------------------------------------------------------------
\66\ Quoting from its study. Brumbelow, M.L., Blanar, L.,
``Evaluation of US Rear Underride Guard Regulation for Large Trucks
Using Real-World Crashes,'' Stapp Car Crash Journal, Vol. 54,
November 2010, pp. 119-131.
---------------------------------------------------------------------------
In response, the data used in the 2010 IIHS study comprised too
small a sample to generalize the extent of low overlap crashes in the
U.S. NHTSA notes that in 22 of the 30 cases, it was not clear whether
the rear impact guards on the trailers were compliant with FMVSS No.
223 and among the 9 low overlap crashes. Seven rear impact guards on
the trailer exhibited deformation similar to that in the IIHS 30
percent overlap crash tests (the lateral end of the guard bent forward
in the impact). In the other 2 cases, the rear impact guards
experienced failure at other locations likely due to the guards being
weak in general. Among the 30 LTCCS cases IIHS analyzed, only 8 were
crashes of passenger vehicles into the rear of trailers with FMVSS No.
223 compliant rear impact guards. Among these 8 trailers, 2 rear impact
guards showed no signs of failure, 3 rear impact guards failed at the
attachment to the trailer structure, 1 rear impact guard bent forward
due to localized loading from a low overlap crash, and 2 rear impact
guards were damaged too severely to determine the failure mechanism. In
other words, the 2010 IIHS study uses too small a data sample to
generalize the extent of low overlap crashes in the U.S. In contrast,
the 2013 UMTRI Study provides a scientific annual estimate of all fatal
crashes into the rear of trailers in the U.S., including offset crashes
and the extent and type of rear impact guard damage in crashes.
Seven Hills said it did not understand why NHTSA was considering
the extent of guard damage, as a fatal collision involving major damage
to a guard should be treated the same as a fatal collision that did not
involve major damage. It also argued that minimal guard damage in fatal
offset impacts indicates that the problem is lack of adequate guard
strength on the outside edges of trailers. The commenter said that the
absence of a difference in the percentage of light vehicle crashes with
PCI in offset crashes and non-offset crashes shows a need to improve
the performance of rear impact guards in low overlap conditions,
particularly when such PCI is occurring in what Seven Hills viewed as
``otherwise non-injurious speed differences.''
In response, NHTSA believes examining the extent of rear impact
guard damage, along with the occurrence of PCI, is important to
determine the utility of improving guards to protect against non-offset
crashes. Rear impact guards sustain more damage in non-offset crashes,
which suggests that non-offset crashes are potentially more harmful and
thus should be addressed first. Our statement that we found no
difference between the percentage of light vehicle crashes with PCI in
offset crashes and non-offset crashes was not meant to suggest that
offset crashes are not a concern. Rather, because (a) more fatal light
vehicle crashes into the rear of trucks and trailers are non-offset
crashes, (b) non-offset occur significantly more frequently than low
overlap crashes (crashes with 30 percent or less overlap of the
impacting vehicle with the rear of the trailer), and (c) non-offset
crashes appear more harmful of the two, NHTSA was explaining why it
decided to pursue this rulemaking on non-low overlap crashes at this
time.
IIHS stated that guard damage is not an adequate metric for the
severity of underride and questioned whether NHTSA could accurately
calculate the extent of guard damage based on TIFA survey data. In
response, NHTSA notes that the damage to the guard was not used to
assess the severity of underride but was part of the information
collected to determine impact severity. The 2013 UMTRI Study used
enhanced data on the rear of the trailer to determine the extent of
guard damage. The severity of underride and the occurrence of PCI were
determined from the light passenger vehicle information.
IIHS noted that the Manac rear impact guard was not the only design
that performed well in the 30 percent overlap crash and that other
designs such as the Vanguard rear impact guard also mitigated PCI in 30
percent overlap crashes. The agency agrees that other rear impact guard
designs that connect directly to the longitudinal frame rails of the
trailer through the vertical members are able to mitigate PCI in 30
percent overlap crashes without reducing protection against PCI in full
and 50 percent overlap crashes. However, as shown later in the section,
these guards add cost and weight to the trailer.
TSC and Advocates stated that, even if the majority of fatal light
vehicle crashes into the rear of trucks and trailers were non-offset
crashes, this still meant that 40 percent were offset
[[Page 42358]]
crashes. Other commenters also disagreed with NHTSA's decision to focus
this rulemaking on fatal non-low overlap crashes, despite that such
crashes occur more frequently than low overlap crashes. In response,
NHTSA notes that this final rule would afford protection to occupants
involved in 56 km/h (35 mph) crashes into the rear of trailers where
the impacting vehicle fully overlaps with the trailer rear, and in
offset crashes where 50 percent of the light vehicle front end overlaps
with the trailer rear, and in offset crashes where a load bearing
vertical member connecting the rear impact guard to the trailer is
engaged by the front end of the impacting vehicle. In response to the
comments, we reiterate some of the details provided in the NPRM and
provide further reasoning below for not proceeding with low overlap
performance requirements in this final rule.
Further Analysis on Requirements for Protection in Low Overlap Crashes
Rear impact guards are designed to absorb energy and prevent PCI by
attaching to substantial structural elements of a trailer or
semitrailer, such as the chassis longitudinal frame rails, by way of
vertical support members. The test results from the initial testing at
IIHS reported in the NPRM show that many trailer rear impact guards
designed to CMVSS No. 223 met the proposed performance requirements in
the NPRM in full overlap and 50 percent overlap crashes but were unable
to prevent PCI in a 35 mph crash into the rear of the trailer where
only 30 percent of the width of the passenger vehicle front end
overlapped with the rear of the trailer. In these 30 percent overlap
crashes, only a small lateral portion of the rear impact guard (about
22 percent of the guard width) engaged with the front end of the
passenger vehicle. This small lateral portion typically did not include
a vertical support member of the guard, so when the passenger vehicle
struck this small lateral portion of the guard, the guard deformed
locally and did not prevent PCI.
In the initial crash tests conducted by IIHS, only the Manac rear
impact guard was able to prevent PCI in the Chevy Malibu in the 56 km/h
(35 mph) full overlap, 50 percent overlap, and the 30 percent overlap
test conditions. Unlike most trailer designs, however, where the
vertical members of the rear impact guard attach directly to the
longitudinal frame rails of the trailer, the vertical members of the
Manac rear impact guard were located further outboard from the location
of the trailer longitudinal frame rails and attached to a reinforced
floor section of the trailer. While the more outboard vertical supports
of the Manac guard improved rear impact protection in low overlap
crashes of light vehicles into the rear of trailers, the further
outboard vertical supports appeared to reduce guard strength near the
center of the horizontal member of the rear impact guard. In the 56 km/
h (35 mph) full overlap crash tests of the Malibu, the greatest amount
of underride (1,350 mm) was in the test with the Manac trailer. In
contrast, the extent of the underride was 990 mm in the test with the
Wabash trailer.
The full overlap IIHS crash test results raise the possibility that
for crash speeds greater than 56 km/h (35 mph), trailers that have the
main vertical supports for the guard more outboard may not perform as
well in full overlap crashes as trailers that have the vertical
supports more inboard. Since full and 50 percent overlap crashes are
more frequent than low overlap (30 percent or less) crashes, and
because most fatal light vehicle impacts into the rear of trailers are
at speeds greater than 56 km/h (35 mph), the agency is concerned that
such guard designs may reduce protection against PCI in the more
frequent higher speed full and 50 percent overlap crashes. NHTSA is
concerned about potential negative safety consequences accruing from a
rule that resulted in designs that moved the vertical members of rear
impact guards more outward laterally to prevent underride in a 56 km/h
(35 mph) 30 percent low overlap crash, if such a rule reduced
protection in full and 50 percent overlap crashes.
NHTSA has estimated the potential benefits of adopting a 30 percent
overlap crash. The agency estimated the number of fatalities in 30
percent or lower overlap crashes in the field based on the available
information, estimated the effectiveness of the rear impact guards that
prevent PCI in 30 percent overlap crashes, and estimated the lives
saved by a requirement for rear impact guards mitigating PCI in 56 km/h
(35 mph) 30 percent overlap crashes.
The 2013 UMTRI Study found that 40 percent of light vehicle impacts
into the rear ends of trucks and trailers in fatal crashes met the
UMTRI definition of ``offset crashes,'' \67\ and that 60 percent were
non-offset impacts. However, for a typical trailer rear width of 2,600
mm, an offset crash defined in the 2013 UMTRI Study is when 867 mm of
the width of the trailer from its lateral edge is engaged by the
impacting vehicle. In contrast, as detailed in the 2015 NPRM, in the
IIHS 30 percent overlap crash of a Malibu with the rear impact guard of
a trailer, the Malibu interacted with only 637 mm of the rear of the
trailer (approximately a quarter of the trailer rear width) from its
lateral edge. This difference is important as it relates to how the
impacting vehicle engages the vertical members connecting the rear
impact guard to the trailer. On a typical 2,600 mm width trailer, the
vertical members connecting the rear impact guard to the trailer are
located at about 753 mm from the left and right lateral edge of the
trailer. Therefore, ``offset'' crashes in the 2013 UMTRI Study included
crashes in which a vertical member of the rear impact guard was
engaged. In contrast, in IIHS's 30 percent overlap crashes, the
vertical members of the rear impact guards were not engaged.
---------------------------------------------------------------------------
\67\ UMTRI defined ``offset crashes'' as impacts with the outer
one-third or less of the rear plane of the trailer. For a 2,600 mm
wide trailer, one-third of the trailer width is 867 mm from the
lateral edge of the trailer, which includes the location of the
vertical member. In contrast, the IIHS 30 percent overlap crash test
is a 30 percent overlap of the impacting vehicle with the trailer
rear. For a 2,600 mm wide trailer, 30 percent overlap of a passenger
vehicle corresponds to 637 mm from the lateral edge of the trailer,
which does not include the location of the vertical member.
---------------------------------------------------------------------------
Stated differently, the definition of an offset crash in the 2013
UMTRI Study includes crashes that would not have been considered low
overlap crashes under IIHS's test program (as they had greater than 30
percent overlap of the front end of the vehicle). NHTSA reviewed a
sample of the crash cases which were identified as ``offset crashes''
in the 2013 UMTRI Study. Based on the damage to the rear impact guard
and the damage to the front end of the impacting vehicle in each of
these offset crash cases, NHTSA determined that in many crashes the
front end of the striking vehicle engaged the portion of the rear
impact guard containing the vertical member, and therefore were not
``low overlap'' crashes as would have been considered under the IIHS
protocol (crashes with 30 percent or less of the impacting vehicle
front end overlapping the rear width of the trailer). This review
indicated that a substantial number of cases identified as ``offset
crashes'' in the 2013 UMTRI Study were not ``low overlap'' crashes like
those in the IIHS 30 percent overlap crash test.
The 2013 UMTRI Study found that there are annually 72 fatalities in
light vehicle crashes into the rear of trailers that result in PCI.
According to this study, almost 40 percent of the impacts by light
vehicles were ``offset,'' meaning that they occurred on the outer left
or right third of a trailer's rear. For trailers
[[Page 42359]]
required to have rear impact guards, there was no difference in the
extent of underride, including PCI, for offset and non-offset impacts
of light vehicles into the rear of trailers.\68\ Therefore, we
determined the number of annual fatalities in offset crashes with PCI
into the rear of trailers as the product of the annual number of
fatalities in light vehicle crashes with PCI into the rear of trailers
(72) and the percentage of offset crashes (40%). Accordingly, the
number of fatalities in offset crashes with PCI from the 2013 UMTRI
Study is 28.8 (=72 x 40%). Yet, as explained above, NHTSA reviewed a
sample of the offset crashes in the 2013 UMTRI Study and found that in
most of these offset crashes, there was more than 30 percent overlap of
the impacting vehicle with the rear of the trailer (demonstrated by the
impacting vehicle having engaged the rear impact guard at the location
of a vertical member). Thus, to estimate the benefit of a requirement
to prevent PCI in 30 percent overlap crashes, NHTSA assumed 20 to 40
percent of these 28.8 annual fatalities \69\ were in crashes with 30
percent or less overlap of the front end of the impacting light vehicle
with the trailer. Therefore, NHTSA estimated that there are 5.8-11.5 (=
28.8 x 20% to 28.8 x 40%) annual fatalities in low overlap crashes into
the rear of trailers.
---------------------------------------------------------------------------
\68\ Figure 5 in the 2013 UMTRI Study. Heavy-Vehicle Crash Data
Collection and Analysis to Characterize Rear and Side Underride and
Front Override in Fatal Truck Crashes, DOT HS 811 725, March 2013,
infra.
\69\ As explained above, NHTSA's review of a sample of offset
crashes into the rear of trailers in the 2013 UMTRI Study indicated
that a majority of these offset crashes were with more than 30
percent overlap of the impacting vehicle with rear of the trailer.
---------------------------------------------------------------------------
The 2013 UMTRI Study also found that only 26 percent of crashes
into the rear of trailers were at relative impact speeds of 56 km/h (35
mph) or less. Though the 2013 UMTRI Study found that the crash speeds
in offset crashes were higher than those in non-offset crashes, NHTSA
used 26 percent to estimate the number of crashes into the rear of
trailers with 30 percent or lower overlap that were at crash speeds 56
km/h (35 mph) or lower. Rear impact guards may not be able to mitigate
all fatalities in crashes into the rear of trailers with relative
velocity of 56 km/h (35 mph) or less because some crashes may be due to
circumstances other than underride (i.e., unrestrained status of
occupants, elderly and other vulnerable occupants, post impact vehicle
kinematics that could expose vehicle to subsequent impacts \70\). For
the purpose of this analysis, NHTSA assumed that the incremental
effectiveness of rear impact guards (CMVSS No. 223 compliant guards
that also mitigate PCI in 30 percent overlap crashes) in preventing
fatalities in light vehicle impacts with 30 percent overlap into the
rear of trailers with crash speeds less than 56 km/h is 50 percent.
Therefore, NHTSA estimated the overall effectiveness of upgrading from
the final rule compliant guards to final rule compliant guards that
also prevent PCI in 30 percent overlap crashes to be 13 percent (=26% x
50%). NHTSA estimates that the annual number of lives saved in low
overlap crashes into the rear of trailers at relative velocities of 56
km/h (35 mph) or less to be 0.75 to 1.5 (= 5.8 x 0.13 to 11.6 x 0.13).
---------------------------------------------------------------------------
\70\ The IIHS tests showed that in 30 percent overlap crashes
where PCI is mitigated, the impacting light vehicle rotates during
the crash and therefore could be exposed to impact by vehicles
traveling in adjacent lanes.
---------------------------------------------------------------------------
To prevent PCI in 30 percent overlap crashes, designs would have to
either: (a) add additional vertical members at the lateral edge of the
rear impact guard that connect to the trailer's transverse floor beam
and strengthen the transverse floor beam of the trailer to withstand
the loads transmitted from these vertical members at the edge of the
guard; or (b) considerably strengthen the rear impact guard member so
it would not deform locally in the 30 percent overlap crash. In these
circumstances all the loads will still be taken up by the longitudinal
chassis rails. This means that both these approaches would add
significant weight to the vehicles because they involve adding more
vertical members, strengthening the floor beams, or strengthening the
guard itself.
Currently, there are 4 trailer manufacturers that offer rear impact
guards that prevent PCI in all three IIHS crash test conditions (35 mph
crash of a passenger vehicle with (1) full overlap, (2) 50 percent
overlap and (3) 30 percent overlap with the rear of the trailer) as
standard equipment. In 2020, the total trailer output of these 4
manufacturers is about 28 percent of the total number of trailers
produced in 2020 (211,807).\71\ Many other trailer manufacturers offer
rear impact guards that prevent PCI in the three IIHS crash test
conditions as optional equipment.
---------------------------------------------------------------------------
\71\ https://cdn.baseplatform.io/files/base/ebm/trailerbodybuilders/document/2021/04/TBB_Top_25_CY2020.6089da057e9d0.pdf.
---------------------------------------------------------------------------
NHTSA reviewed the rear impact guard offerings in the trailer
industry. The incremental cost and weight increase of a trailer with a
rear impact guard that prevents PCI of passenger vehicles in all three
overlap conditions (full, 50 percent, and 30 percent overlap) compared
to an equivalent trailer by the same manufacturer with a rear impact
guard that meets the performance requirements of this final rule \72\
ranges from $100 to $1,000 and from 25 kg (55 lb) to 118 kg (260 lb),
respectively. The large range in cost and weight is because some
trailers need significant modifications to accommodate rear impact
guards with 30 percent overlap protection, the higher cost of high-
strength/light-weight materials for the guard, and other such factors.
The weighted average (weights based on trailers produced in 2020) \73\
of this incremental cost and weight increase of trailers with rear
impact guards which prevent PCI in 30 percent overlap crashes is $306
and 35 kg (77 lb), respectively.
---------------------------------------------------------------------------
\72\ As noted previously, the final rule requirements ensure
preventing PCI in a 35 mph passenger vehicle crash with full and 50
percent overlap with the rear of a trailer.
\73\ https://cdn.baseplatform.io/files/base/ebm/trailerbodybuilders/document/2021/04/TBB_Top_25_CY2020.6089da057e9d0.pdf.
---------------------------------------------------------------------------
Stoughton Trailer, a trailer manufacturer, produces trailers with
rear impact guards that prevent PCI in all three overlap conditions at
56 km/h (35 mph) as standard equipment and notes on its website that
its rear impact guards do not add additional weight, cost, or
negatively impact aerodynamics (presumably compared to rear impact
guards that would meet this final rule requirements).\74\ The Stoughton
rear impact guard, made of steel, includes two vertical supports on the
outer ends of the horizontal member that fasten to a robust
undercarriage of the trailer. It does not appear feasible engineering-
wise for the additional material (two steel vertical members on the
outer edge of the horizontal member that is bolted to a reinforced
undercarriage) not to add weight or cost to the trailer. Accordingly,
NHTSA decided not to include this guard design in this analysis.
---------------------------------------------------------------------------
\74\ https://www.stoughtontrailers.com/Portals/0/documents/Rear%20Underride%20Guard%20Sales%20Sheet.pdf.
---------------------------------------------------------------------------
There are some unique rear impact guard designs that meet the
performance requirements in this final rule and are also able to
mitigate PCI in 30 percent overlap crashes without significant increase
in weight. However, these unique designs may have restrictions in
intermodal operations at loading docks \75\ and may not be practicable
for
[[Page 42360]]
all types of trailers covered by FMVSS No. 224. The benefit-cost
analysis assumes intermodal operability is maintained and so these
unique rear impact guard designs were not considered for this analysis.
---------------------------------------------------------------------------
\75\ In order to comply with Occupational Safety and Health
Administration (OSHA) requirements (OSHA 29 CFR 1910.26(d)), loading
docks have vehicle restraints that are designed to connect to rear
impact guards to prevent the vehicle from moving during loading and
unloading operations. Unique rear impact guard designs that are
wider than 7.5 inches, with unique profiles (such as pentagonal
shapes) have provided challenges to connect the vehicle restraints
to the rear impact guard.
---------------------------------------------------------------------------
There are 211,807 trailers produced in 2020 \76\ among which 65
percent (137,675 = 211,806 x 65%) are required to be equipped with rear
impact guards, of which 28 percent are already equipped with rear
impact guards that meet the performance requirements of this final rule
and mitigate PCI in 30 percent overlap crashes. The annual average and
minimal incremental fleet cost of equipping all new applicable trailers
\77\ (99,126 = 137,675 x 72%) with rear impact guards that mitigate PCI
in 30 percent overlap crashes is $30.3 million (= 99,126 x $306) and
$9.9 million (= 99,126 x $100).
---------------------------------------------------------------------------
\76\ Id.
\77\ There were 211,807 new trailers produced in 2020, among
which 65 percent (137,675 = 211,807 x 0.65) are required to be
equipped with rear impact guards. Among applicable trailers, 21
percent are already equipped with guards that mitigate PCI in 30
percent overlap crashes.
---------------------------------------------------------------------------
In addition, the average weight increase of 35 kg (77 lb) from
installing a guard that could mitigate PCI in a 30 percent overlap
crash would increase fuel consumption. With 192,000 class 8 truck
annual sales,\78\ the total average incremental lifetime fuel cost is
estimated to be $130 million undiscounted, $106 million with 3 percent
discounting, and $84 million with 7 percent discounting. If the minimum
weight increase of 25 kg (55 lb) is used instead, the total minimum
incremental lifetime fuel cost is estimated to be $93 million
undiscounted, $75 million with 3 percent discounting, and $60 million
with 7 percent discounting. The overall undiscounted cost increase
(material cost and lifetime fuel cost) is $161 million on average and
$103 million at a minimum.
---------------------------------------------------------------------------
\78\ See statista for class 8 truck annual sales (https://www.statista.com/statistics/261416/class-3-8-truck-sales-in-the-united-states/).
---------------------------------------------------------------------------
NHTSA is required by Section 1 of Executive Order 12866 to conduct
a benefit cost analysis of any proposed regulatory requirements.\79\
The undiscounted cost per life saved using the average cost estimate
ranges from $107 million to $215 million, while that using the minimum
cost estimate ranges from $69 million to $138 million, which is
significantly greater than the value of a statistical life ($11.6
million).\80\ Therefore, a requirement for equipping all new applicable
trailers with rear impact guards that mitigate PCI in 30 percent
overlap crashes is not cost-effective.\81\ This indicates that total
costs of such a requirement exceed overall benefits. Detailed
calculations for the benefits, costs, and cost per life saved are
provided in the FRE accompanying this final rule.\82\
---------------------------------------------------------------------------
\79\ ``Significant'' regulatory actions are also subject to
Section 6 to assess potential benefits and costs.
\80\ For more information on the value of a statistical life,
see a 2021 Office of the Secretary memorandum on the ``Guidance on
Treatment of the Economic Value of a Statistical Life in U.S.
Department of Transportation Analyses--2021 Update.'' https://www.transportation.gov/office-policy/transportation-policy/revised-departmental-guidance-on-valuation-of-a-statistical-life-in-economic-analysis.
\81\ Cost-effectiveness represents a measure of the average
monetary cost per unit of change (benefit). In regulatory analyses
for safety policies, cost-effectiveness generally measures the
average estimated change in total costs per unit improvement in
safety (e.g., cost per life saved). A policy alternative can be
considered cost-effective if the estimated cost per unit increase is
less than an appropriate benchmark. For example, a proposed safety
standard could be considered cost-effective if the average cost per
life saved equivalent (i.e., combining lives saved and injuries
avoided, weighted by the relative values of injuries to fatalities)
under the proposed standard were less than the comprehensive
economic cost of a fatality ($11.6 million in 2020 dollars). That
is, the proposed standard would yield safety benefits at a lower
cost than the benchmark value for those benefits.
\82\ NHTSA has placed a copy of the FRE in the docket for this
final rule.
---------------------------------------------------------------------------
For the above reasons, we have determined that an FMVSS that
requires vehicles to provide rear impact protection in 56 km/h (35 mph)
full-frontal, 50 percent overlap, and 30 percent overlap not to be
reasonable or practicable. We conclude that such a revision would not
meet the requirements of Section 30111(a) and (b) of the Safety Act for
issuance of Federal motor vehicle safety standards. Accordingly, we
have decided to refrain from adopting a requirement for a 30 percent
overlap crash at this time.
However, as explained above, the Federal standards act as a floor,
not a ceiling, to establish the minimum level of performance that meet
the safety needs presented by the data. FMVSS are written in terms of
minimum performance requirements for motor vehicles or motor vehicle
equipment to protect the public against unreasonable risk of injury and
death in crashes. Manufacturers have flexibility in design as long as
their products comply with applicable FMVSS. There are rear impact
guard designs in the current trailer and semitrailer market that
prevent PCI in all three crash conditions described in Section
23011(b)(1)(A) of BIL: (1) full overlap crash, (2) 50 percent overlap
crash, and (3) 30 percent overlap crash at 56 km/h impact speed. While
data do not support the agency's requiring these guards for all
vehicles, this final rule does not preclude these designs from being on
the trailer and semi-trailer market.
Some commenters suggested design changes to rear impact guards that
they viewed as increasing protection in low overlap conditions. Network
requested that NHTSA require a barrier width within 100 mm of the
trailer's outer frame; Advocates similarly stated that if rear impact
guards were extended, protection against underride would be enhanced.
Network and Ms. Wood also suggested that rear impact guards have angled
struts attached to the ends of the guard. Batzer recommended that
guards have support at their corners, while Seven Hills stated that a
solution could be using three- or four-vertical support configurations.
The VT Group suggested that stronger material selection for the
horizontal member can improve a rear impact guard's load capability
during low overlap crashes.
In response, NHTSA does not believe that it is reasonable, or
appropriate, to mandate in this rulemaking that rear impact guards have
designs of the specificity suggested by the commenters. The design of
rear impact guards is dependent on trailer geometry and structure and
we do not wish to unnecessarily restrict the flexibility of
manufacturers to design appropriate guards. NHTSA also does not believe
that it should mandate the materials used in constructing rear impact
guards, as our standards are performance oriented.\83\ Finally, this
issue was not proposed in the NPRM and is not within the scope of this
rulemaking.
---------------------------------------------------------------------------
\83\ 49 U.S.C. 30102(a)(10).
---------------------------------------------------------------------------
d. Half-Guard Testing
CMVSS No. 223 allows for compliance testing on half of a symmetric
rear impact guard through an application of a 175,000 N distributed
load at the P3 location. NHTSA determined that half guard testing was
not needed in FMVSS No. 223 and explained in the NPRM why it did not
propose the inclusion of half-guard testing in the proposal.
Comments Received
Commenters on this issue all argued in favor of including an option
allowing for testing of half of the rear impact guard. TTMA, Strick,
and Mr. Young stated their general belief that testing on a half-guard
will produce the same result as testing on the full guard. They further
suggested that half-guard testing
[[Page 42361]]
is beneficial to manufacturers, as they can test one half-guard, make
any changes to the second half-guard, and then test the modified second
half-guard with less time and effort. TTMA also remarked that allowing
an option for half-guard testing would ensure maximum harmonization
with the Canadian standard CMVSS No. 223.
Agency Response
NHTSA reviewed the comments and confirms its earlier decision that
a half-guard testing option is not needed in FMVSS No. 223. As noted in
the NPRM, CMVSS No. 223 allows for half-guard testing because at the
time the standard was written, guard manufacturers lacked the equipment
to apply a distributed force of 350,000 N as would be required in a
test of the full guard. CMVSS No. 223 thus allowed manufacturers to use
then existing equipment to certify rear impact guards through half-
guard testing. No commenter suggested that this rationale should be
applied to FMVSS No. 223 or that manufacturers presently lack the
capability to conduct tests on a full guard. Significantly, there is
also an absence of data showing that half-guard testing provides
results representative of full guard performance.
NHTSA notes that the test procedures included in an FMVSS specify
the compliance tests that NHTSA conducts. Manufacturers may use other
reasonable methods to certify the compliance of their vehicles or
equipment, provided that their vehicle or motor vehicle equipment
complies. In other words, any changes to FMVSS Nos. 223 and 224 would
not directly affect how manufacturers choose to structure their guard
development processes, as long as the vehicle or equipment complies. If
manufacturers believe that testing on half-guards will allow them to
better iterate designs, the standard does not prevent them from doing
so. The guard must meet the FMVSS when tested by NHTSA according to the
test procedures in the standard.
e. Retrofitting
The NPRM did not propose to require used trailers be retrofitted
with CMVSS No. 223 compliant rear impact guards, as NHTSA had estimated
in the NPRM that the cost of retrofitting all applicable FMVSS
compliant trailers far exceeds the total benefits from such a retrofit
requirement.
Comments Received
Many commenters disagreed with NHTSA's decision not to propose that
all trailers be retrofitted with newly compliant guards. Network
commented that older guards can be easily fixed. Messrs. Kiefer and
Young remarked that more lives would be saved if NHTSA required
retrofitting. TSC remarked that NHTSA underestimated the potential
benefits to requiring trailers be retrofitted. TSC stated that NHTSA
based its analysis on the number of light vehicle crashes into the rear
of trailers that resulted in PCI, which TSC claimed came from data
sources that often do not report on intrusion. Conversely, ATA stated
that retrofitting trailers will have a negative cost-benefit ratio,
stating that there are more than 11.7 million commercial trailers
registered in the states in 2012, many of which are not used on a
regular basis. ATA argued that retrofitting them would create
significant costs without any corresponding benefit.
Agency Response
As further detailed in the Final Regulatory Evaluation (FRE)
accompanying this final rule, NHTSA evaluated requiring all trailers to
be retrofitted with CMVSS No. 223 compliant guards. This evaluation
suggests that such a requirement would not be practicable or cost-
effective. Further, vehicle owners would need to assess each trailer-
guard combination individually to determine whether an upgraded guard
would be compatible with the used trailer, accounting for age and
condition of the vehicle. A used trailer may not be structurally
capable of accommodating a new upgraded guard without the addition of
unique parts. Owners may not have the technical expertise to know if an
upgraded rear impact guard installed on a used trailer would be able to
meet the intended performance level.
VI. Lead Time
The NPRM proposed a lead time of two years following the date of
publication of a final rule. NHTSA received mixed comments on the
proposed lead time. Mr. Young and Network remarked that given most
trailers already meet the proposed requirements, a two-year lead time
was unnecessary. Mr. Young stated that NHTSA instead should require
immediate compliance. TTMA commented that, for ``nearly all trailer
models,'' TTMA members have the capability to manufacture to the
proposed standard but suggested that manufacturers of other models may
have to develop and test new rear impact guards. TTMA suggested a lead
time that provides for an optional early compliance date may be
worthwhile.
Section 23011(b)(1)(B) of BIL provides that the regulations
promulgated under subparagraph (A) shall require full compliance with
each FMVSS revised pursuant to those regulations not later than 2 years
after the date on which those regulations are promulgated.
After considering the comments and Section 23011(b)(1)(B) of BIL,
NHTSA is adopting a two-year compliance date. The agency estimates that
94 percent of new trailers sold in the United States subject to FMVSS
Nos. 223 and 224 already comply with the requirements of this final
rule. This means, however, that there remain many trailer manufacturers
who will need time and resources to design and produce new rear impact
guards that are compliant with this final rule. Establishing too short
a lead time will disadvantage these manufacturers, many of which may be
small manufacturers. NHTSA proposed a two-year lead time for the 1996
final rule and the agency believes this length of time is consistent
with BIL and remains appropriate. Manufacturers may choose to comply
with the new standards earlier.
VII. Benefit-Cost Analysis
For the NPRM, NHTSA developed a Preliminary Regulatory Evaluation
(PRE) to estimate the benefits and cost of this rulemaking. We first
estimated the annual number of fatalities and injuries in light vehicle
crashes with PCI into the rear of trailers that could be prevented by
the rulemaking.\84\ We found that, annually, there are 72 light vehicle
occupant fatalities in crashes into the rear of trailers with rear
impact guards with PCI.\85\ About 26 percent of fatal light vehicle
crashes into the rear of trailers occur at speeds of 56 km/h (35 mph)
or less, the speeds at which this rule would be effective. Thus, the
agency estimated that there are 19 fatalities (= 72 x 0.26) that occur
in crashes with a relative velocity of 56 km/h (35 mph) or less.
---------------------------------------------------------------------------
\84\ NHTSA did not include non-PCI crashes into the rear of
trailers into the analysis of benefits of the final rule because the
agency assumed that the passenger vehicle's restraint systems, when
used, would mitigate injury.
\85\ NHTSA only counted crashes into trailers with rear impact
guards as these would be the only trailers that NHTSA assumes would
equip upgraded rear impact guards and thus be affected by this rule.
---------------------------------------------------------------------------
CMVSS No. 223 guards may not be able to mitigate all fatalities in
crashes into the rear of trailers with relative velocity of 56 km/h (35
mph) or less because some crashes may involve low overlap (30 percent
or less) and some fatalities may be due to circumstances other than
underride (e.g., unrestrained status of occupants). NHTSA thus assumed
that the incremental effectiveness of CMVSS No. 223
[[Page 42362]]
compliant guards over FMVSS No. 224 compliant guards in preventing
fatalities in light vehicle impacts with PCI into the rear of trailers
with crash speeds less than 56 km/h (35 mph) is 50 percent.\86\ Since
only 26 percent of light vehicle crashes with PCI into the rear of
trailers are at relative velocity less than or equal to 56 km/h, NHTSA
estimated the overall effectiveness of upgrading to CMVSS No. 223
compliant guards to be 13 percent (= 26% x 50%).
---------------------------------------------------------------------------
\86\ The estimation of rear impact guard effectiveness is
detailed in the FRE. Fatalities and injuries would also depend on
other factors such as occupant age, seat belt use, and crash
dynamics. Considering these factors, and using engineering judgement
we believe 50 percent is a reasonable estimate of the effectiveness
of CMVSS compliant rear impact guards.
---------------------------------------------------------------------------
Since a number of vehicles currently meet CMVSS No. 223, this
benefit must be reduced by the proportion of new trailers already
compliant with CMVSS No. 223, which the agency estimated to be 93
percent. Assuming 13 percent effectiveness of these guards in fatal
crashes with PCI into the rear of trailers, the agency estimated that
about 0.66 (= 72 x (1-0.93) x 0.13) lives would be saved annually by
requiring all applicable trailers to be equipped with CMVSS No. 223
compliant guards. NHTSA estimated that a total of 2.7 serious injuries
would also be prevented annually with this rear impact guard rule.
Including fatalities and serious injuries, the agency estimated that
1.4 equivalent lives would be saved annually.
To determine the costs of the final rule, NHTSA considered the
incremental fleet cost of equipping all applicable trailers with CMVSS
No. 223 rear impact guards and the increased fuel costs resulting from
the added weight CMVSS No. 223 compliant guards would place on
trailers.
The average cost of a Canadian compliant rear impact guard was
estimated as $492. The incremental cost of equipping CMVSS No. 223
compliant rear impact guards on applicable new trailers (those that are
subject to FMVSS No. 223) was estimated as $229 per trailer. There were
243,873 trailers produced in 2013,\87\ among which 65 percent were
required to be equipped with rear impact guards. Of those, 93 percent
were already equipped with CMVSS No. 223 compliant guards. The annual
incremental fleet cost of equipping all applicable trailers with CMVSS
No. 223 rear impact guards was estimated at $2.5 million (= 243,873 x
0.65 x (1.0-0.94) x $229).
---------------------------------------------------------------------------
\87\ https://trailer-bodybuilders.com/trailer-output/2014-trailer-production-figures-table.
---------------------------------------------------------------------------
NHTSA determined that upgrading from the FMVSS No. 223 compliant
guard to the CMVSS No. 223 compliant guard would add an average
incremental weight of 22.2 kg (48.9 lb) to the trailer, thereby
reducing the overall fuel economy during the lifetime of the trailer.
The incremental increase in lifetime fuel cost for a 22.2 kg (48.9 lb)
weight increase of a trailer was estimated to be $1,042.2 and $927.7
discounted at 3 percent and 7 percent, respectively. The annual
incremental lifetime fuel cost of equipping all applicable trailers
with CMVSS No. 223 rear impact guards was estimated as $9.2 million and
$8.2 million in 2013 dollars discounted at 3 percent and 7 percent,
respectively.
The agency estimated that the net cost per equivalent lives saved
would be $9.1 million and $9.5 million in 2013 dollars discounted at 3
percent and 7 percent, respectively. At 3 percent discount rate, the
net benefit of the proposed rule would be $0.59 million. At 7 percent
discount rate, the net benefit of the proposed rule would be $0.13
million.
Comments. NHTSA received several comments on the estimates provided
in the NPRM. A few commenters suggested NHTSA should not conduct a
benefit-cost analysis for a safety focused regulation in the first
place and/or should comply with Vision Zero and make saving human life
a priority over monetary issues. Some others believed that NHTSA's
benefit-cost analysis was fundamentally flawed because, they argued:
safety-related benefits should intrinsically outweigh costs related to
upgrading equipment, NHTSA should not shift the costs of its rule to
the public at the benefit of truckers, or that NHTSA should use costs
only to compare outcomes that involved a rear impact guard not failing
upon collision.
Agency Response. NHTSA implements its regulatory, enforcement, and
oversight authority provided by the National Traffic and Motor Vehicle
Safety Act (49 U.S.C. Chapter 301) (Safety Act) to protect all members
of the public. NHTSA's authority to issue Federal motor vehicle safety
standard is set forth in sections 30111 of the Safety Act. Each safety
standard must be practicable, meet the need for motor vehicle safety,
and be stated in objective terms. When issuing a safety standard, NHTSA
must consider, among other things, relevant motor vehicle safety
information, whether a standard is reasonable, practicable, and
appropriate for the particular type of motor vehicle or motor vehicle
equipment for which it is prescribed, and the extent to which the
standard will carry out section 30101 of the Act.\88\ NHTSA issues its
regulations in accordance with agency and Departmental regulations and
in conformity with Executive orders (E.O.).
---------------------------------------------------------------------------
\88\ Section 30101 sets forth the purpose and policy of the
Safety Act.
---------------------------------------------------------------------------
Safety is of utmost importance, and NHTSA pursues such safety to
the degree possible in accordance with its statutory authority and as
instructed by Executive order. Under the Safety Act, the reasonableness
and practicability of a standard (both technologically and
economically) must be considered. Under E.O. 12866, agencies are
instructed to undertake a benefit-cost analysis to inform its
rulemaking decisions to ensure agency regulations protect and improve
the public's health, safety, environment, and well-being and improves
the performance of the economy without imposing unacceptable or
unreasonable costs on society. Thus, in response to commenters who urge
us to adopt safety standards without regard to costs, we cannot do so
under the Safety Act and the E.O.
NHTSA also cannot measure safety-related benefits categorically
differently from costs, as requested by several commenters. Under E.O.
12866, as specified in OMB Circular A-4, agencies must quantify and
value safety impacts to compare them to the costs of the regulation.
Agencies do so by calculating the value of the loss of life using a
metric called the Value of a Statistical Life (VSL). The VSL includes
costs such as medical care, reduced income, and the effects fatalities
and injuries may have on family members. NHTSA uses the VSL to
determine the monetary value of reducing fatalities and injuries, which
NHTSA then compares to estimated costs of a regulation. NHTSA cannot
arbitrarily increase the value of benefits outside of this framework.
Some commenters also raised issues with what they viewed as
specific shortcomings in the PRE's benefit-cost analysis. Some believed
NHTSA did not properly consider all necessary variables in its
analysis. For example, Network stated that NHTSA did not consider new
technology or what it claimed to be the negative consumer choices
fueled by fear to adopt smaller and lighter fuel-efficient vehicles due
to increased crash incompatibility. Mr. Karth believed NHTSA should
consider ``what a parent would pay to protect their children,'' the
``impact upon a family if a bread-winner is injured or lost,'' and
``the medical expenses to care for a severely injured individual.'' Ms.
Karth believed NHTSA's benefit-cost
[[Page 42363]]
analysis did not ``take into consideration the circumstances and costs
of the full extent of underride research.''
NHTSA has prepared a Final Regulatory Evaluation (FRE) for this
final rule and has placed a copy of the FRE in the docket.\89\ The FRE
for this final rule discusses and explains the agency's final estimates
for the benefits and cost that would result from this rulemaking. The
analysis and findings are not significantly different from those of the
PRE.
---------------------------------------------------------------------------
\89\ The FRE may be obtained by downloading it or by contacting
Docket Management at the address or telephone number provided at the
beginning of this document.
---------------------------------------------------------------------------
NHTSA believes that it has properly calculated the applicable
benefits and costs to its rule using the appropriate variables. We
sought to estimate the benefits of the rule by determining the number
of lives and serious injuries it would prevent over the current
situation and then monetize that number using the VSL value. We then
compared these benefits with the cost of the rule, the increased
material and fuel costs that requiring rear impact guard upgrades would
necessitate. These variables encompass the benefits and costs that this
rule would impose. In the absence of sufficient information to quantify
changes in consumer behavior, we do not believe that factoring in
variables such as negative consumer choices resulting from the fear of
underride collisions is appropriate.
Some comments remarked on what were perceived to be NHTSA's
overestimation of projected costs. Mr. Karth questioned NHTSA's
calculations as being overstated, particularly emphasizing that the
fuel costs NHTSA projected in the PRE did not turn out to be accurate.
The commenter also believed NHTSA's benefit-cost analysis is faulty
because manufacturers have been willing to ``provide a better rear
impact guard even without regulation.'' Ms. Karth commented that
customers have shown they are willing to pay for trailers to be safer,
and manufacturers have shown that they are willing to respond to that
demand and produce safer trailers. Network believed that NHTSA used
outdated costs when analyzing how much an upgraded rear impact guard
would cost. Mr. Brown indicated that the costs of the regulation could
``be distributed to many different people and products.''
Agency Response. We disagree that we overestimated the costs of the
rule. We determined the incremental cost of installing CMVSS No. 223
compliant guards on all trailers that would need to upgrade to new
guards and the resulting increase in fuel costs such installation would
cause. While commenters pointed to factors they believed NHTSA should
have considered, we do not believe such considerations are appropriate.
For example, Mr. and Ms. Karth suggested that manufacturers have been
willing to provide a better rear impact guard and that consumers have
shown that they are willing to pay more for vehicles to have upgraded
rear impact guards. The fact, however, that some manufacturers and
consumers may be willing to accept increased costs is not relevant to
estimating the increased costs of the guards, which is a factor germane
to an analysis that seeks to quantify the costs of the rule and analyze
societal impacts. Similarly, while Network remarked that NHTSA's
estimates for the value of an upgraded rear impact guard were too high,
it did so by reflecting on what it thought the cost of a guard should
be. NHTSA determined this cost by looking to the average cost of CMVSS
No. 223 compliant guards on the market, which the agency believes
reflects a more realistic and accurate value.
In response to Mr. Karth's comment regarding NHTSA's estimated fuel
costs from the PRE, NHTSA followed well established procedures to
estimate incremental fuel costs due to increased weight of the rear
impact guards and the most recent information on fuel price. NHTSA
considered the most up-to-date data in developing this final rule,
updated its variables where necessary in the FRE and used the most
current data available to inform this rulemaking.
Some commentators stated that NHTSA underestimated the benefits of
improved rear impact guards. According to Advocates, NHTSA based its
calculation of the proposed rule's benefits on the agency's belief that
only 26 percent of light vehicle occupant fatal crashes into the rear
of trailers with rear impact guards that resulted in PCI occur at
speeds of 35 mph or less. Advocates believed that using this number
``significantly reduced the agency's estimate of the number of crashes
and occupants that could be aided by the upgrade in rear protection
guards'' because it is based on speed estimates, which Advocates
considers ``notoriously inaccurate.'' TSC similarly commented that
NHTSA derived speed estimates from ``inconsistent, unreliable sources''
and failed to count instances of PCI properly, resulting in NHTSA's
underestimating the benefits of the intended rule.
Agency Response. NHTSA has analyzed the comments and believes it
has properly calculated the benefits of this rulemaking. The agency
determined the number of fatalities and serious injuries this rule
would prevent by analyzing the supplemented TIFA data from the 2013
UMTRI Study. This data source is the most accurate available to
determine the number of fatalities and serious injuries currently
caused by fatal light vehicle crashes into the rear of trailers with
PCI at speeds of 56 km/h (35 mph) or less--the crashes NHTSA is
targeting in this rule. We have used these data appropriately for
determining the target population and estimating the benefits and in
accordance with OMB Circular A-4 \90\ guidance on the development of
regulatory analysis. NHTSA also notes that, while commenters objected
to using data based on speed estimates and determinations of PCI, they
did not present any alternative data source they believed was more
reliable. The TIFA data have been thoroughly apprised for accuracy and
are the best data available for an analysis of benefits. NHTSA has
concluded the data are sufficient to proceed with quantifying the
benefits of this rulemaking and to proceed to a final rule.
---------------------------------------------------------------------------
\90\ https://obamawhitehouse.archives.gov/omb/circulars_a004_a-4/.
---------------------------------------------------------------------------
Summary of the Final Regulatory Evaluation
The estimated benefits and costs of the FRE are along the same
lines as those in the PRE. In the FRE, NHTSA determined that 94 percent
of applicable new trailers are now equipped with rear impact guards
that are compliant with the updated FMVSS No. 223 requirements.
Additionally, NHTSA updated the value of statistical life (VSL) in
accordance with the March 2021 Department of Transportation revised
guidance regarding the treatment of the economic value of a statistical
life in U.S Department of Transportation regulatory analyses (2021
Update).\91\
---------------------------------------------------------------------------
\91\ For more information, please see a 2021 Office of the
Secretary memorandum on the ``Guidance on Treatment of the Economic
Value of a Statistical Life in U.S. Department of Transportation
Analyses--2021 Update.'' https://www.dot.gov/policy/transportation-policy/economy.
---------------------------------------------------------------------------
Assuming 13 percent effectiveness of these guards in fatal crashes
with PCI into the rear of trailers, the agency estimates that about
0.56 (= 72 x (1-0.94) x 0.13) lives would be saved annually by
requiring all applicable trailers to be equipped with CMVSS No. 223
compliant guards. The agency also estimates that a total of 3.5 serious
injuries would be prevented annually with the rear impact guard final
rule. Including fatalities and serious injuries,
[[Page 42364]]
the rule would result in an estimated 1.4 equivalent lives saved
annually.
NHTSA estimates the annual incremental fleet cost of equipping all
applicable trailers with CMVSS No. 223 rear impact guards to be $2.1
million based on an average increase in cost of $254.35 per guard. The
annual incremental lifetime fuel cost, based on an average weight
increase of 48.9 pound per vehicle, is estimated to be $5.59 million
and $4.43 million discounted at 3 percent and 7 percent, respectively.
Therefore, the total cost of the final rule, including material and
fuel costs, is $7.69 million discounted at 3 percent and $6.54 million
discounted at 7 percent.
The agency estimates that the cost per equivalent life saved is
$6.77 million and $7.25 million discounted at 3 percent and 7 percent,
respectively, as shown in Table 5. A summary of the regulatory cost and
net benefit of the final rule at the 3 percent and 7 percent discount
rates are presented in Table 6. At 3 percent discount rate, the net
benefit of the final rule is $6.04 million. At 7 percent discount rate,
the net benefit of the final rule is $4.36 million.
Table 5--Cost per Equivalent Life Saved
[In millions of 2020 dollars]
----------------------------------------------------------------------------------------------------------------
Discount rate Undiscounted 3% 7%
----------------------------------------------------------------------------------------------------------------
Total Cost...................................................... $9.00 $7.69 $6.54
Equivalent Lives Saved.......................................... 1.40 1.14 0.90
Cost per Equivalent Life Saved.................................. $6.42 $6.77 $7.25
----------------------------------------------------------------------------------------------------------------
Table 6--Net Benefits
[In millions of 2020 dollars]
----------------------------------------------------------------------------------------------------------------
Discount rate Undiscounted 3% 7%
----------------------------------------------------------------------------------------------------------------
Comprehensive Benefit........................................... $16.96 $13.73 $10.90
Total Cost...................................................... 9.00 7.69 6.54
-----------------------------------------------
Net Benefit................................................. 7.96 6.04 4.36
----------------------------------------------------------------------------------------------------------------
For further information regarding the aforementioned cost and
benefit estimates, please reference the FRE that NHTSA placed in the
docket.
VIII. Regulatory Notices and Analyses
Executive Order (E.O.) 12866 (Regulatory Planning and Review), E.O.
13563, and DOT Regulatory Policies and Procedures
We have considered the impacts of this final rule under Executive
Orders 12866 and 13563, and the Department of Transportation's
administrative rulemaking procedures. This final rule has been
determined to be nonsignificant under E.O. 12866 and was not reviewed
by OMB. We have discussed comments to the PRE and summarized the
estimated costs, benefits, and cost-effectiveness of this final rule in
the above section of this preamble, and in the FRE. NHTSA estimates
that this final rule will save approximately 1.14 and 0.9 equivalent
lives annually discounted at 3 percent and 7 percent, respectively. The
total cost of the final rule, including material and fuel costs, is
estimated to be $7.69 million discounted at 3 percent and $6.54 million
discounted at 7 percent. The net cost per equivalent lives saved is
$6.77 million and $7.25 million discounted at 3 percent and 7 percent,
respectively. NHTSA's FRE fully discusses the estimated costs,
benefits, and other impacts of this rule.
Consistent with E.O. 13563, NHTSA is amending FMVSS Nos. 223 and
224 because of retrospectively analyzing the effectiveness of the
standards. NHTSA realized the merits of CMVSS No. 223 in addressing the
same safety need that is the subject of FMVSS Nos. 223 and 224 and
undertook this rulemaking to adopt upgraded strength and other
requirements of CMVSS No. 223.
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 a notice
of proposed rulemaking or final rule, it must prepare and make
available for public comment a regulatory flexibility analysis that
describes the effect of the rule on small entities (i.e., small
business, small organizations, and small governmental jurisdictions),
unless the head of an agency certifies the rule will not have a
significant economic impact on a substantial number of small entities.
Agencies must also provide a statement of the factual basis for this
certification.
I certify that this rule will not have a significant economic
impact on a substantial number of small entities. NHTSA estimates there
are 354 manufacturers of trailers in the U.S., 331 of which are small
businesses. The impacts of this final rule on small trailer
manufacturers would not be significant. This rule will make changes to
the strength requirements applying to rear impact guards but will not
affect the method by which small trailer manufacturers can certify
compliance with FMVSS Nos. 223 and 224.
FMVSS No. 223, an equipment standard, specifies strength and energy
absorption requirements in quasi-static force tests of rear impact
guards sold for installation on new trailers and semitrailers. FMVSS
No. 224, a vehicle standard, requires new trailers and semitrailers
with a GVWR of 4,536 kg (10,000 lb) or more to be equipped with a rear
impact guard meeting FMVSS No. 223. NHTSA established the two-standard
approach to provide underride protection in a manner that imposes
reasonable compliance burdens on small trailer manufacturers.
Under FMVSS No. 223, the guard may be tested for compliance while
mounted to a test fixture or to a complete trailer. FMVSS No. 224
requires that the guard be mounted on the trailer or semitrailer in
accordance with the instructions provided with the guard by the guard
manufacturer. Under this approach, a small manufacturer that produces
relatively few trailers can certify its trailers to FMVSS No. 224
without feeling compelled to undertake destructive testing of what
could be a substantial portion of its production. The two-standard
approach was devised to provide small manufacturers a
[[Page 42365]]
practicable and reasonable means of meeting the safety need served by a
rear impact guard requirement. This final rule does not change the
method of certifying compliance to the rear impact guard requirements
of FMVSS Nos. 223 and 224.
National Environmental Policy Act
NHTSA has analyzed this final rule for the purposes of the National
Environmental Policy Act and determined that it will not have any
significant impact on the quality of the human environment.
Executive Order 13132 (Federalism)
NHTSA has examined this final rule pursuant to Executive Order
13132 (64 FR 43255, August 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 rulemaking would not have sufficient federalism implications
to warrant consultation with State and local officials or the
preparation of a federalism summary impact statement. The final rule
will 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 preempt 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 chapter 301, 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 chapter 301. 49 U.S.C.
30103(b)(1). It is this statutory command by Congress that preempts any
non-identical State legislative and administrative law addressing the
same aspect of performance.
The express preemption provision described above is subject to a
savings clause under which ``[c]ompliance 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. However, the Supreme
Court has recognized the possibility, in some instances, of implied
preemption of such State common law tort causes of action by virtue of
NHTSA's rules, even if not expressly preempted. This second way that
NHTSA rules can preempt is dependent upon there being an actual
conflict between an FMVSS and the higher standard that would
effectively be imposed on motor vehicle manufacturers if someone
obtained a State common law tort judgment against the manufacturer,
notwithstanding the manufacturer's compliance with the NHTSA standard.
Because most NHTSA standards established by an FMVSS are minimum
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 Orders 13132 and 12988, NHTSA has considered
whether this final 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 final rule and
finds that this rule, like many NHTSA rules, prescribes only a minimum
safety standard. As such, NHTSA does not intend that this final rule
will 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 minimum standard in this final rule.
Without any conflict, there could not be any implied preemption of a
State common law tort cause of action.
Executive Order 12988 (Civil Justice Reform)
When promulgating a regulation, Executive Order 12988 specifically
requires that the agency must make every reasonable effort to ensure
that the regulation, as appropriate: (1) Specifies in clear language
the preemptive effect; (2) specifies in clear language the effect on
existing Federal law or regulation, including all provisions repealed,
circumscribed, displaced, impaired, or modified; (3) provides a clear
legal standard for affected conduct rather than a general standard,
while promoting simplification and burden reduction; (4) specifies in
clear language the retroactive effect; (5) specifies whether
administrative proceedings are to be required before parties may file
suit in court; (6) explicitly or implicitly defines key terms; and (7)
addresses other important issues affecting clarity and general
draftsmanship of regulations.
Pursuant to Executive Order 12988, NHTSA notes as follows: The
preemptive effect of this final rule 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 proceedings before they may file suit in
court.
Paperwork Reduction Act
Under the Paperwork Reduction Act of 1995 (PRA), 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. Before
seeking OMB approval, Federal agencies must provide a 60-day public
comment period and otherwise consult with members of the public and
affected agencies concerning each collection of information
requirement. There are no PRA requirements associated with this final
rule.
National Technology Transfer and Advancement Act
Under the National Technology Transfer and Advancement Act of 1995
(NTIAA) (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., material specifications, test methods, sampling procedures, and
business practices) that are developed or adopted by voluntary
consensus standards bodies, such as the International Organization for
Standardization (ISO) and the Society of Automotive Engineers (SAE).
The NTTAA directs us to provide Congress, through OMB, explanations
when we decide not to use available and applicable voluntary consensus
standards.
This final rule will adopt requirements of CMVSS No. 223. NHTSA's
consideration of CMVSS No. 223 accords with the principles of NTTAA, in
that NHTSA is considering
[[Page 42366]]
an established, proven standard, and has not had to expend significant
agency resources on the same safety need addressed by CMVSS No. 223.
Unfunded Mandates Reform Act
Section 202 of the Unfunded Mandates Reform Act of 1995 (UMRA),
Public Law 104-4, requires Federal 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
expenditure by State, local, or tribal governments, in the aggregate,
or by the private sector, of more than $100 million annually (adjusted
for inflation with base year of 1995). After analyzing the costs of
this final rule, it will not result in expenditures by any of the
aforementioned entities of over $100 million annually.
Executive Order 13609 (Promoting International Regulatory Cooperation)
The policy statement in section 1 of Executive Order 13609 provides
in part that the regulatory approaches taken by foreign governments may
differ from those taken by U.S. regulatory agencies to address similar
issues. The E.O. states that, in some cases, the differences between
the regulatory approaches of U.S. agencies and those of their foreign
counterparts might not be necessary and might impair the ability of
American businesses to export and compete internationally. The E.O.
states that, in meeting shared challenges involving health, safety,
labor, security, environmental, 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 that international regulatory cooperation can also
reduce, eliminate, or prevent unnecessary differences in regulatory
requirements.
This final rule adopts requirements of CMVSS No. 223 to upgrade
FMVSS Nos. 223 and 224. NHTSA recognizes that these requirements are
different from those in the European standard, ECE R.58, ``Rear
underrun protective devices (RUPD); Vehicles with regard to the
installation of an RUPD of an approved vehicle; Vehicles with regard to
their rear underrun protection.'' \92\ R.58 specifies requirements that
are similar to, but less stringent than, the current standards in FMVSS
Nos. 223 and 224. R.58 specifies a quasi-static loading test of 25 kN
at P1, 25 kN at P2, and 100 kN at P3. R.58 also does not specify any
energy absorption requirements. NHTSA has decided to adopt the strength
requirements of CMVSS No. 223 rather than ECE R.58 because the rear
impact protection requirements for trailers in Canada are more
stringent than that in Europe and more appropriate for the underride
crashes experienced in the U.S. Passenger vehicles in the U.S. are
required by FMVSS No. 208 to have frontal air bag protection and comply
with a full frontal 56 km/h (35 mph) rigid barrier crash test by
ensuring that the injury measures of crash test dummies restrained in
front seating positions are within the allowable limits. CMVSS No. 223
is designed to prevent PCI in full frontal 56 km/h (35 mph) crashes.
Together, FMVSS No. 208 and FMVSS Nos. 223 and 224 will significantly
reduce the harm resulting to occupants of passenger vehicles impacting
the rear of trailers in crashes of up to 56 km/h (35 mph).
---------------------------------------------------------------------------
\92\ Economic Commission of Europe (ECE) R.58, ``Rear underrun
protective devices (RUPDs); Vehicles with regard to the installation
of an RUPD of an approved type; Vehicles with regard to their rear
underrun protection (RUP),'' February 2019, https://www.unece.org/fileadmin/DAM/trans/main/wp29/wp29regs/2017/R058r3e.pdf.
---------------------------------------------------------------------------
Plain Language
Executive Order 12866 require each agency to write all rules in
plain language. Application of the principles of plain language
includes consideration of the following questions:
Has the agency 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 is
not 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 the agency improve clarity by adding tables, lists,
or diagrams?
What else could the agency do to make this rulemaking
easier to understand?
If you have any responses to these questions, please send them to
NHTSA.
Privacy Act
In accordance with 5 U.S.C. 553(c), DOT solicits comments from the
public to better inform its rulemaking process. DOT posts these
comments, without edit, including any personal information the
commenter provides, to www.regulations.gov, as described in the system
of records notice (DOT/ALL-14 FDMS), which can be reviewed at
www.dot.gov/privacy.
Regulation Identifier Number
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 hearing at the beginning of this document
to find this action in the Unified Agenda.
List of Subjects in 49 CFR Part 571
Motor vehicle safety, Motor vehicles, Reporting and recordkeeping
requirements, Tires.
In consideration of the foregoing, NHTSA amends 49 CFR part 571 as
follows:
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
0
1. The authority citation for part 571 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. Section 571.223 is amended by:
0
a. Revising S3;
0
b. Adding definitions of ``Ground clearance'' and ``Load path'' in
alphabetical order in S4;
0
c. Revising S5.2, S5.5(c), S6 introductory text, S6.3, S6.4
introductory text, S6.4(a) introductory text, and S6.4(b) introductory
text;
0
d. Removing S6.4(c);
0
e. Revising S6.5 introductory text and S6.5(a);
0
f. Adding S6.5(c);
0
g. Revising S6.6 introductory text, S6.6(b), and S6.6(c);
0
f. Adding S6.7 through S6.9;
0
g. Revising Figures 1 and 2; and
0
h. Adding Figures 3 and 4.
The revisions and additions read as follows:
Sec. 571.223 Standard No. 223; Rear impact guards
* * * * *
S3. Application. This standard applies to rear impact guards for
trailers and semitrailers subject to Federal Motor Vehicle Safety
Standard No. 224, Rear Impact Protection (Sec. 571.224).
S4. * * *
Ground clearance means the vertical distance from the bottom edge
of a horizontal member to the ground.
* * * * *
Load path means a route of force transmission between the
horizontal member and the chassis.
* * * * *
S5.2 Strength and Energy Absorption. When tested under the
[[Page 42367]]
procedures of S6 of this section, each guard shall comply with the
strength requirements of S5.2.1 of this section at each test location
and the energy absorption requirements of S5.2.2 of this section when a
distributed load is applied uniformly across the horizontal member, as
specified in S6.8 of this section. However, a particular guard (i.e.,
test specimen) need not be tested at more than one location.
S5.2.1 Guard Strength. The guard must resist the force levels
specified in S5.2.1(a) through (c) of this section without deflecting
by more than 125 mm and without eliminating any load path that existed
before the test was initiated.
(a) A force of 50,000 N applied in accordance with S6.6 of this
section at test location P1 on either the left or the right side of the
guard as defined in S6.4(a) of this section.
(b) A force of 50,000 N applied in accordance with S6.6 of this
section at test location P2 as defined in S6.4(b) of this section.
(c) A uniform distributed force of at least 350,000 N applied
across the horizontal member, as specified in S6.8 of this section and
in accordance with S6.6 of this section.
S5.2.2 Guard Energy Absorption.
(a) A guard, other than a hydraulic guard or one installed on a
tanker trailer, when subjected to a uniform distributed load applied in
accordance with S6.6(c) of this section:
(1) Shall absorb by plastic deformation at least 20,000 J of energy
within the first 125 mm of deflection without eliminating any load path
that existed before the test was initiated; and
(2) Have a ground clearance not exceeding 560 mm, measured at each
support to which the horizontal member is attached, as shown in Figure
4 of this section, after completion of the load application.
(b) A guard, other than a hydraulic guard or one installed on a
tanker trailer, that demonstrates resistance to a uniform distributed
load greater than 700,000 N applied in accordance with S6.6(b) of this
section, need not meet the energy absorption requirements of S5.2.2(a)
of this section but must have a ground clearance not exceeding 560 mm
at each vertical support to which the horizontal member is attached
after completion of the 700,000 N load application.
* * * * *
S5.5 * * *
(c) An explanation of the method of attaching the guard to the
chassis of each vehicle make and model listed or to the design elements
specified in the instructions or procedures. The principal aspects of
vehicle chassis configuration that are necessary to the proper
functioning of the guard shall be specified including the maximum
allowable vertical distance between the bottom edge of the horizontal
member of the guard and the ground to ensure post-test ground clearance
requirements are met. If the chassis strength is inadequate for the
guard design, the instructions or procedures shall specify methods for
adequately reinforcing the vehicle chassis. Procedures for properly
installing any guard attachment hardware shall be provided.
S6. Guard Test Procedures. The procedures for determining
compliance with S5.2 of this section are specified in S6.1 through S6.9
of this section.
* * * * *
S6.3 Point Load Force Application Device. The force application
device employed in S6.6 of this section consists of a rectangular solid
made of rigid steel. The steel solid is 203 mm in height, 203 mm in
width, and 25 mm in thickness. The 203 mm by 203 mm face of the block
is used as the contact surface for application of the forces specified
in S5.2.1(a) and (b) of this section. Each edge of the contact surface
of the block has a radius of curvature of 5 mm plus or minus 1 mm.
S6.4 Point Load Test Locations. With the guard mounted to the rigid
test fixture or to a complete trailer, determine the test locations P1
and P2 in accordance with the procedure set forth in S6.4(a) and (b) of
this section. See Figure 1 of this section.
(a) Point Load Test location P1 is the point on the rearmost
surface of the horizontal member of the guard that:
* * * * *
(b) Point Load Test location P2 is the point on the rearmost
surface of the horizontal member of the guard that:
* * * * *
S6.5 Positioning of Force Application Device. Before applying any
force to the guard, locate the force application device specified in
S6.3 of this section for the point load test location and that
specified in S6.7 of this section for the uniform distributed load test
location, such that:
(a) The center point of the contact surface of the force
application device is aligned with and touching the guard test
location, as defined by the specifications of S6.4 of this section for
the point load test locations, and S6.8 of this section for the uniform
distributed load test location.
* * * * *
(c) If the guard is tested on a rigid test fixture, the vertical
distance from the bottom edge of the horizontal member to the ground at
the location of each support to which the horizontal member is
attached, shall be measured.
S6.6 Force Application. After the force application device has been
positioned according to S6.5 of this section, at the point load test
locations specified in S6.4 of this section or the uniform distributed
load test location specified in S6.8 of this section, apply the loads
specified in S5.2 of this section. Load application procedures are
specified in S6.6(a) through (d) of this section.
* * * * *
(b) If conducting a strength test to satisfy the requirement of
S5.2.1 or S5.2.2(b) of this section, the force is applied until the
forces specified in S5.2.1 or S5.2.2(b) of this section have been
exceeded, or until the displacement of the force application device has
reached at least 125 mm whichever occurs first.
(c) If conducting a test to be used for the calculation of energy
absorption levels to satisfy the requirement of S5.2.2(a) of this
section, apply a uniform distributed force to the guard until
displacement of the force application device, specified in S6.7 of this
section, has reached 125 mm. For calculation of guard energy
absorption, the value of force is recorded at least ten times per 25 mm
of displacement of the contact surface of the loading device. Reduce
the force until the guard no longer offers resistance to the force
application device. Produce a force vs. deflection diagram of the type
shown in Figure 2 of this section using this information. Determine the
energy absorbed by the guard by calculating the shaded area bounded by
the curve in the force vs. deflection diagram and the abscissa (X-
axis).
* * * * *
S6.7 Uniform Distributed Load Force Application Device. The force
application device to be employed in applying the uniform distributed
load is to be unyielding, have a height of 203 mm, and have a width
that exceeds the distance between the outside edges of the outermost
supports to which the tested portion of the horizontal member is
attached, as shown in Figure 3 of this section.
S6.8 Uniform Distributed Load Test Location. With the guard mounted
to the rigid test fixture or to a complete trailer, determine the test
location in accordance with the following procedure. See Figure 3 of
this section. Distributed Force Test location is the plane on the
rearmost surface of the horizontal member of the guard that:
[[Page 42368]]
(a) Is centered in the longitudinal vertical plane passing through
the center of the guard's horizontal member; and
(b) Is centered 50 mm above the bottom of the guard.
S6.9 Ground Clearance Measurement.
(a) For the test device attached to a complete trailer as specified
in S6.2 of this section, the ground clearance of the guard at the
vertical supports to which the horizontal member is attached shall be
measured after completion of the uniform distributed load test in
accordance with S6.6(b) or S6.6(c) of this section.
(b) For the test device attached to a rigid test fixture as
specified in S6.2 of this section, the vertical distance from the
ground to the bottom edge of the horizontal member at the vertical
supports to which the horizontal member is attached shall be measured
after completion of the uniform distributed load test in accordance
with S6.6(b) or S6.6(c) of this section and subtracted from the
corresponding ground clearance measured before the load application in
accordance with S6.5(c) of this section. The difference in ground
clearance before and after the load application is added to the
allowable maximum vertical distance between the bottom edge of the
horizontal member of the guard and the ground as specified in S5.5(c)
of this section, to obtain the ground clearance after completion of the
uniform distributed load test.
BILLING CODE 4910-59-P
[[Page 42369]]
[GRAPHIC] [TIFF OMITTED] TR15JY22.003
[[Page 42370]]
[GRAPHIC] [TIFF OMITTED] TR15JY22.004
[[Page 42371]]
[GRAPHIC] [TIFF OMITTED] TR15JY22.005
[[Page 42372]]
[GRAPHIC] [TIFF OMITTED] TR15JY22.006
BILLING CODE 4910-59-C
0
3. Section 571.224 is amended by revising the second sentence in S3 and
the definition of ``Rear extremity'' in S4 to read as follows:
Sec. 571.224 Standard No. 224; Rear impact protection.
* * * * *
S3. Application. * * * The standard does not apply to pole
trailers, pulpwood trailers, low chassis vehicles, road construction
controlled horizontal discharge trailers, special purpose vehicles,
wheels back vehicles, or temporary living quarters as defined in 49 CFR
523.2. * * *
S4. * * *
Rear extremity means the rearmost point on a trailer that is above
a horizontal plane located above the ground clearance and below a
horizontal plane located 1,900 mm above the ground when the trailer is
configured as specified in S5.1 of this
[[Page 42373]]
section and when the trailer's cargo doors, tailgate and other
permanent structures are positioned as they normally are when the
trailer is in motion, with non-structural protrusions excluded from the
determination of the rearmost point, such as:
(1) Tail lamps;
(2) Rubber bumpers;
(3) Hinges and latches; and
(4) Flexible aerodynamic devices capable of being folded to within
305 mm from the transverse vertical plane tangent to the rear most
surface of the horizontal member for vertical heights below 1,740 mm
above ground and, when positioned as they normally are when the trailer
is in motion, are located forward of the transverse plane that is
tangent to the rear bottom edge of the horizontal member and
intersecting a point located 1,210 mm rearward of the horizontal member
and 1,740 mm above the ground.
* * * * *
Issued under authority delegated in 49 CFR 1.95 and 501.5.
Steven S. Cliff,
Administrator.
[FR Doc. 2022-14330 Filed 7-14-22; 8:45 am]
BILLING CODE 4910-59-P