[Federal Register Volume 74, Number 90 (Tuesday, May 12, 2009)]
[Rules and Regulations]
[Pages 22348-22393]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: E9-10431]
[[Page 22347]]
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Part IV
Department of Transportation
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National Highway Traffic Safety Administration
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49 CFR Parts 571 and 585
Federal Motor Vehicle Safety Standards; Roof Crush Resistance; Phase-In
Reporting Requirements; Final Rule
Federal Register / Vol. 74, No. 90 / Tuesday, May 12, 2009 / Rules
and Regulations
[[Page 22348]]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Parts 571 and 585
[Docket No. NHTSA-2009-0093]
RIN 2127-AG51
Federal Motor Vehicle Safety Standards; Roof Crush Resistance;
Phase-In Reporting Requirements
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.
ACTION: Final rule.
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SUMMARY: As part of a comprehensive plan for reducing the risk of
rollover crashes and the risk of death and serious injury in those
crashes, this final rule upgrades the agency's safety standard on roof
crush resistance in several ways.
First, for the vehicles currently subject to the standard, i.e.,
passenger cars and multipurpose passenger vehicles, trucks and buses
with a Gross Vehicle Weight Rating (GVWR) of 2,722 kilograms (6,000
pounds) or less, the rule doubles the amount of force the vehicle's
roof structure must withstand in the specified test, from 1.5 times the
vehicle's unloaded weight to 3.0 times the vehicle's unloaded weight.
Second, the rule extends the applicability of the standard so that it
will also apply to vehicles with a GVWR greater than 2,722 kilograms
(6,000 pounds), but not greater than 4,536 kilograms (10,000 pounds).
The rule establishes a force requirement of 1.5 times the vehicle's
unloaded weight for these newly included vehicles. Third, the rule
requires all of the above vehicles to meet the specified force
requirements in a two-sided test, instead of a single-sided test, i.e.,
the same vehicle must meet the force requirements when tested first on
one side and then on the other side of the vehicle. Fourth, the rule
establishes a new requirement for maintenance of headroom, i.e.,
survival space, during testing in addition to the existing limit on the
amount of roof crush. The rule also includes a number of special
provisions, including ones related to leadtime, to address the needs of
multi-stage manufacturers, alterers, and small volume manufacturers.
DATES: If you wish to petition for reconsideration of this rule, your
petition must be received by June 26, 2009.
Effective date: The date on which this final rule amends the CFR is
July 13, 2009. The incorporation by reference of a publication listed
in the rule is approved by the Director of the Federal Register as of
July 13, 2009.
Compliance dates:
Passenger cars and multipurpose passenger vehicles, trucks and
buses with a GVWR of 2,722 kilograms (6,000 pounds) or less. This final
rule adopts a phase-in of the upgraded roof crush resistance
requirements for these vehicles. The phase-in begins on September 1,
2012. By September 1, 2015, all of these vehicles must meet the
upgraded requirements, with certain exceptions. Vehicles produced in
more than one stage and altered vehicles need not meet the upgraded
requirements until September 1, 2016.
Multipurpose passenger vehicles, trucks and buses with a GVWR
greater than 2,722 kilograms (6,000 pounds) and less than or equal to
4,536 kilograms (10,000 pounds). All of these vehicles must meet the
requirements beginning September 1, 2016, with certain exceptions.
Vehicles produced in more than one stage and altered vehicles need not
meet the requirements until September 1, 2017.
ADDRESSES: If you wish to petition for reconsideration of this rule,
you should refer in your petition to the docket number of this document
and submit your petition to: Administrator, National Highway Traffic
Safety Administration, 1200 New Jersey Avenue, SE., West Building,
Washington, DC 20590.
The petition will be placed in the docket. Anyone is able to search
the electronic form of all documents received into any of our dockets
by the name of the individual submitting the document (or signing the
document, if submitted on behalf of an association, business, labor
union, etc.). You may review DOT's complete Privacy Act Statement in
the Federal Register published on April 11, 2000 (Volume 65, Number 70;
Pages 19477-78) or you may visit http://www.dot.gov/privacy.html.
FOR FURTHER INFORMATION CONTACT: For non-legal issues, you may call
Christopher J. Wiacek, NHTSA Office of Crashworthiness Standards,
telephone 202-366-4801. For legal issues, you may call J. Edward
Glancy, NHTSA Office of Chief Counsel, telephone 202-366-2992. You may
send mail to these officials at the National Highway Traffic Safety
Administration, 1200 New Jersey Avenue, SE., West Building, Washington,
DC 20590.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Executive Summary
a. Final Rule
b. How This Final Rule Differs From the NPRM and/or SNPRM
II. Overall Rollover Problem and the Agency's Comprehensive Response
a. Prevention
b. Occupant Containment
c. Occupant Protection
III. The Role of Roof Intrusion in the Rollover Problem
IV. The Agency's Proposed Rule
a. NPRM
b. SNPRM
c. Congressional Mandate
V. Overview of Comments
VI. Agency Decision and Response to Comments
a. Primary Decisions
1. Basic Nature of the Test Requirements--Quasi-Static vs.
Dynamic Tests
2. Vehicle Application
3. Single-Sided or Two-Sided Tests
4. Upgraded Force Requirement--Specified Strength to Weight
Ratio (SWR)
5. Performance Criteria--Headroom, Platen Travel, or Both
6. Leadtime and Phase-In
b. Aspects of the Test Procedure
1. Tie-Down Procedure
2. Platen Angle and Size
3. Testing Without Windshields and/or Other Glazing in Place
4. Deletion of Secondary Plate Positioning Procedure
5. Removal of Roof Components
6. Tolerances
c. Requirements for Multi-Stage and Altered Vehicles
d. Other Issues
1. Convertibles and Open Bodied Vehicles
2. Vehicles Without B-Pillars
3. Heavier Vehicles With a High Height to Width Aspect Ratio
4. Active Roofs
5. Whether an Additional SNPRM Is Needed
6. Rear Seat Occupants
7. New Car Assessment Program (NCAP)
8. Possible Energy Requirement
9. Advanced Restraints
VII. Costs and Benefits
VIII. Rulemaking Analyses and Notices
Appendix A--Analysis of Comments Concerning Dynamic Testing
Appendix B--Two-Sided Test Results
Appendix C--Single-Sided Test Results
I. Executive Summary
a. Final Rule
As part of a comprehensive plan for reducing the serious risk of
rollover crashes and the risk of death and serious injury in those
crashes, this final rule upgrades Federal Motor Vehicle Safety Standard
(FMVSS) No. 216, Roof Crush Resistance.
For the vehicles currently subject to the standard, passenger cars
and multipurpose passenger vehicles, trucks and buses with a GVWR of
2,722 kilograms (6,000 pounds) or less, the rule doubles the amount of
force the vehicle's roof structure must withstand in the specified
test, from 1.5 times the
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vehicle's unloaded weight to 3.0 times the vehicle's unloaded weight.
The rule also extends the applicability of the standard so that it will
also apply to vehicles with a GVWR greater than 2,722 kilograms (6,000
pounds), but not greater than 4,536 kilograms (10,000 pounds),
establishing a force requirement of 1.5 times the vehicle's unloaded
weight for these heavier vehicles.
Under today's rule, all of the above vehicles must meet the
specified force requirements in a two-sided test instead of a single-
sided test, i.e., the same vehicle must meet the force requirements
when tested first on one side and then on the other side of the
vehicle. The rule also establishes a new requirement for maintenance of
headroom, i.e., survival space, during testing, in addition to the
existing limit on the amount of roof crush. The rule also includes
special provisions to address the needs of multi-stage manufacturers,
alterers, and small volume manufacturers.
NHTSA developed its proposal to upgrade roof crush resistance
requirements after considerable analysis and research, including
considering comments received in response to a Request for Comments
(RFC) notice published in 2001. Prior to publishing the RFC, the agency
conducted a research program to examine potential methods for improving
the roof crush resistance requirements. The agency testing program
included full vehicle dynamic rollover testing, inverted vehicle drop
testing, and comparing inverted vehicle drop testing to a modified
FMVSS No. 216 test. After considering the results of the testing and
other available information, the agency concluded that the quasi-static
procedure provides a suitable representation of the real-world dynamic
loading conditions, and the most appropriate one on which to focus our
upgrade efforts.
Today's rule reflects careful consideration of comments we received
in response to the notice of proposed rulemaking (NPRM) published in
2005 and a supplemental notice of proposed rulemaking (SNPRM) published
in January 2008. NHTSA published the SNPRM to obtain public comment on
a number of issues that might affect the content of the final rule,
including possible variations in the proposed requirements. In the
SNPRM, the agency also announced the release of the results of various
vehicle tests conducted since the NPRM.
While this rulemaking action to improve roof strength is part of
our comprehensive plan for addressing the serious problem of rollover
crashes, this action, by itself, addresses a relatively small subset of
that problem. There are more than 10,000 fatalities in rollover crashes
each year. To address that problem, our comprehensive plan includes
actions to (1) reduce the occurrence of rollovers, (2) mitigate
ejection, and (3) enhance occupant protection when rollovers occur
(improved roof crush resistance is included in this third category).
Our analysis shows that of the more than 10,000 fatalities that
occur in rollover crashes each year, roof strength is relevant to only
about seven percent (about 667) of those fatalities. We estimate that
today's rule will prevent 135 of those 667 fatalities.
The portions of our comprehensive plan that will have the highest
life-saving benefits are the ones to reduce the occurrence of rollovers
(prevention) and to mitigate ejection (occupant containment). We
estimate that by preventing rollovers, electronic stability control
(ESC) will reduce the more than 10,000 fatalities that occur in
rollover crashes each year by 4,200 to 5,500 fatalities (and also
provide significant additional life-saving benefits by preventing other
types of crashes). In the area of mitigating ejection, significant
life-benefits are and/or will occur by our continuing efforts to
increase seat belt use and our upcoming rulemaking on ejection
mitigation. A more complete discussion of our comprehensive plan is
discussed later in this document.
b. How This Final Rule Differs From the NPRM and/or SNPRM
The more noteworthy changes from the NPRM are outlined below and
explained in detail later in this preamble. More minor changes are
discussed in the appropriate sections of this preamble.
Higher force requirement (strength-to-weight ratio (SWR level)).
While we proposed an SWR level of 2.5 in the NPRM for the vehicles that
have been subject to the standard, we noted in the SNPRM that the
agency could adopt a higher or lower value for this final rule. We are
adopting an SWR of 3.0 for them in this final rule. An SWR of 1.5 will
apply to the heavier light vehicles that have previously not been
subject to the standard.
Two-sided test. While we proposed a single-sided test in the NPRM,
we conducted additional testing and addressed the possibility of a two-
sided test in the SNPRM. Today's rule adopts a two-sided test
requirement for all vehicles subject to the standard.
Maintaining intrusion limit in addition to new headroom
requirement. In the NPRM, we proposed to replace the current limit on
intrusion (platen travel requirement) with a new headroom requirement.
For this final rule, we are maintaining the intrusion limit as well as
adopting the proposed headroom requirement.
Use of headform positioning fixture instead of a test dummy. In the
NPRM, we proposed to use test dummies as part of the test procedure for
measuring headroom. For this final rule, we are using headform
positioning fixtures for this purpose.
Phase-in. We did not include a phase-in in the NPRM. For this final
rule, we are phasing in the upgraded roof strength requirements for the
lighter vehicles previously subject to FMVSS No. 216, and providing
longer leadtime (without a phase-in) for the heavier light vehicles.
Limited exclusion for certain multi-stage trucks. Due to concerns
about practicability, we are excluding from FMVSS No. 216 a very
limited group of multistage trucks with a GVWR greater than 2,722
kilograms (6,000 pounds), ones not built on either a chassis cab or an
incomplete vehicle with a full exterior van body.
Updated benefits and costs. We have updated our analysis of
benefits and costs. Our analysis appears in summary form in this
document, and in its entirety in the agency's Final Regulatory Impact
Analysis (FRIA).
We estimate that the changes in FMVSS No. 216 will prevent 135
fatalities and 1,065 nonfatal injuries annually. The agency estimates
that compliance with the upgraded roof strength standard will increase
lifetime consumer costs by $69-114 per affected vehicle. Redesign costs
are expected to increase affected vehicle prices by an average of about
$54. Added weight is estimated to increase the lifetime cost of fuel
usage by $15 to $62 for an average affected vehicle. Total consumer
costs are expected to range from $875 million to $1.4 billion annually.
Implied Preemption. We have reconsidered the tentative position
presented in the NPRM. We do not foresee any potential State tort
requirements that might conflict with today's final rule. Without any
conflict, there could not be any implied preemption.
II. Overall Rollover Problem and the Agency's Comprehensive Response
Addressing vehicle rollovers is one of NHTSA's highest safety
priorities. According to 2007 FARS crash data, 10,196 people were
killed as occupants
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in light vehicle rollover crashes, which represents 35 percent of all
occupants killed that year in crashes. FARS reported that approximately
57 percent were partially or completely ejected from the vehicle
(including approximately 47 percent who were completely ejected).
Rollover crashes are complex and chaotic events. Rollovers can
range from a single quarter turn to eight or more quarter turns, with
the duration of the rollover crash lasting from one to several seconds.
The wide range of rollover conditions occurs because these crashes
largely occur off road where the vehicle motion is highly influenced by
roadside conditions. Also, rollover crashes tend to occur at higher
speeds than other crash types due to the energy required to initiate
the rollover motion.
NHTSA has been pursuing a comprehensive and systematic approach
towards reducing the fatalities and serious injuries that result from
rollover crashes. As part of our safety standard rulemaking, this
approach establishes various repeatable test procedures and performance
requirements that will generate countermeasures effective in the
chaotic real-world events. Due to the complex nature of a rollover
event and the particularized effect of each element of the
comprehensive approach taken by the agency to address these crashes,
each element addresses a specific segment of the total rollover
problem. Accordingly, each initiative has a different target population
and interacts with each of the other rollover strategies. NHTSA has
initiatives in place to:
1. Reduce the occurrence of rollover crashes (e.g., the requirement
for ESC on all light vehicles and the NCAP rollover ratings),
2. Keep occupants inside the vehicle when rollovers occur (e.g.,
NHTSA's unyielding commitment to get passengers to buckle their seat
belts every time they ride in a vehicle, as well as the requirement for
enhanced door latches and the forthcoming rulemaking for ejection
mitigation), and
3. Better protect the occupants kept inside the vehicle during the
rollover (e.g., the requirement for upper interior head protection and
this rulemaking for enhanced roof crush resistance).
Each of these three initiatives must work together to address the
various aspects of the rollover problem.
a. Prevention
The most effective way to reduce deaths and injuries in rollover
crashes is to prevent the rollover crash from occurring. On April 6,
2007, NHTSA published a final rule establishing FMVSS No. 126,
``Electronic stability control systems,'' to require ESC on passenger
cars, multipurpose passenger vehicles, trucks, and buses with a GVWR of
4,536 kilograms (10,000 pounds) or less. ESC systems use automatic
computer-controlled braking of individual wheels to assist the driver
in maintaining control in critical driving situations in which the
vehicle is beginning to lose directional stability at the rear wheels
or directional control at the front wheels. ESC systems effectively
monitor driver steering input and limit vehicle oversteer and
understeer, as appropriate. To comply with the new ESC standard,
vehicles will need individually adjustable braking at all four wheels,
and computer electronics to utilize this capability, a means for engine
torque adjustability and various onboard sensors (to measure yaw rate,
lateral acceleration, steering wheel angle and speed). The agency
estimates that ESC will save 5,300 to 9,600 lives in all types of
crashes annually once all light vehicles on the road are equipped with
ESC. The agency further anticipates that ESC systems will substantially
reduce (by 4,200 to 5,500 deaths) the more than 10,000 deaths each year
resulting from rollover crashes.
b. Occupant Containment
Studies have shown that the fatality rate for an ejected vehicle
occupant is three times as great as that for an occupant who remains
inside of the vehicle. Thus, mitigating ejections offers potential for
significant safety gains. Safety belts are the most effective
crashworthiness countermeasure in reducing ejected rollover fatalities.
Studies have found that safety belts reduce fatalities in rollovers by
74 percent in passenger cars and 80 percent for light trucks.\1\ NHTSA
requires all vehicles manufactured after 1968 to have safety belts as
standard equipment.
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\1\ Kahane, C. J., Fatality Reduction by Safety Belts for Front-
Seat Occupants of Cars and Light Trucks: Updated and Expanded
Estimates Based on 1986-99 FARS Data (NHTSA Report No. DOT HS 809
199).
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However, of the 6,164 ejected occupant fatalities in light vehicle
rollover crashes, as reported by 2006 FARS, 1,135 were classified as
partial ejections. Fatal injuries from partial ejection can occur even
to belted occupants, e.g., when their head protrudes outside the window
and strikes the ground in a rollover. Therefore, as mandated by
SAFETEA-LU, NHTSA is working to establish performance standards to
reduce partial and complete ejection from outboard seating position
windows.
Doors represent another common ejection route. As part of the
agency's comprehensive approach to rollover, and to harmonize with the
first Global Technical Regulation, NHTSA upgraded FMVSS No. 206, ``Door
locks and door retention components,'' in a final rule published on
February 6, 2007. This final rule added test requirements for sliding
doors, upgraded the door retention requirements, added secondary latch
requirements for doors other than hinged side doors and back doors, and
provided a new test procedure for assessing inertial forces. To comply
with the new requirements, it is anticipated that passenger vehicles
with sliding doors designed with one latch and pin locking mechanism
will need to be redesigned with two latches. The technology needed to
meet the upgraded standard would benefit vehicles in rollover crashes
where door openings were identified as a problem.
c. Occupant Protection
Finally, when a rollover crash does occur and the occupants have
been contained within the vehicle compartment, it is important for the
roof structure to remain intact and maintain survival space. That is
the safety need addressed by today's final rule.
III. The Role of Roof Intrusion in the Rollover Problem
Due to the high effectiveness of ESC in preventing an increasing
number of rollover crashes, and seat belts at preventing ejection, the
remaining target population relevant to roof crush occupant protection
is a relatively small subset of the occupants injured in rollovers. For
fatalities, the estimated total for the target population \2\ is about
seven percent (about 667) of all non-convertible light vehicle rollover
fatalities. Although the target population and potential for lives
saved are substantially smaller than can be attained by the first two
strategies of our comprehensive rollover plan, it is nevertheless a
very important aspect of the plan.
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\2\ The target population estimates were based upon the results
from the 1997-2006 National Automotive Sampling System-
Crashworthiness Data System (NASS-CDS).
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Looking at the target population relevant to roof crush occupant
protection more specifically, Table 1 below shows a breakdown of the
target population that could potentially benefit from roof crush
improvements. The target population for all light vehicles is
stratified by injury severity. The injury mechanism due to roof crush
for belted occupants is that the roof crushes during the roll event,
intrudes
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into the occupant compartment, and causes head, face, or neck injury.
The table demonstrates how the final target population is derived from
the broad category of rollovers by eliminating cases in which roof
strength improvements would not be effective in reducing serious and
fatal injuries. For example, a stronger roof would not be expected to
provide benefits in cases where the roof was not involved; where the
occupant was totally ejected from the vehicle,\3\ or where the most
serious injury was not to the head, neck, or face due to the intruding
roof.
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\3\ Strashny, ``The Role of Vertical Roof Intrusion in
Predicting Occupant Ejection,'' 2009. Strashny found that there was
no statistically significant relationship between the level of roof
intrusion and the probability of complete ejection. For this reason
completely ejection occupants were excluded from the target
population. However, partial ejections that meet the established
criteria are included.
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The final target populations are shown in bold at the bottom of the
table. A full discussion of the basis for the target population is
included in the FRIA.
Table 1--Target Population Potentially Affected by Improved Roof Strength \4\
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AIS 1 AIS 2 AIS 3-5 Fatalities
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All Light Vehicles
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All Vehicles:
Non-Convertible Light Vehicles in Rollovers. 199,822 37,305 21,673 10,150
Roof-Involved Rollover...................... 164,213 32,959 19,262 8,645
Some Fixed Object Collision on Top.......... 153,520 29,419 17,766 7,559
Not Totally Ejected......................... 149,850 26,033 12,355 3,654
Using Safety Restraints..................... 116,670 14,327 8,970 2,096
Outboard Seats.............................. 115,018 14,241 8,781 2,096
Roof Component Intrusion.................... 68,730 10,922 6,842 1,444
===============================================================
Head, Neck, or Face Injury From Intruding 24,035 6,580 2,993 957
Roof Component.............................
Injury--Not MAIS \5\........................ 0 -1,900 -1,252 -237
Injury at MAIS--Not Sole Injury............. -17,818 -292 -253 -53
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Sole MAIS Injury........................ 6,216 4,388 1,487 667
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Light Vehicles With a GVWR of 2,722 Kilograms (6,000 Pounds) or Less
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PC & LT < 6,000 lbs:
Non-Convertible Light Vehicles in Rollovers. 172,846 33,170 18,929 8,719
Roof-Involved Rollover...................... 144,410 29,098 17,360 7,536
Some Fixed Object Collision on Top.......... 136,080 26,270 16,122 6,484
Not Totally Ejected......................... 133,241 23,400 11,406 3,142
Using Safety Restraints..................... 104,571 12,421 8,379 1,936
Outboard Seats.............................. 103,249 12,373 8,190 1,936
Roof Component Intrusion.................... 60,061 9,370 6,372 1,304
===============================================================
Head, Neck, or Face Injury From Intruding 20,687 5,868 2,615 842
Roof Component.............................
Injury--Not MAIS............................ 0 -1,771 -1,119 -157
Injury at MAIS--Not Sole Injury................. -16,082 -262 -212 -50
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Sole MAIS Injury........................ 4,605 3,835 1,283 635
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Light Vehicles With a GVWR above 2,722 Kilograms (6,000 Pounds)
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LT > 6,000 lbs:
Non-Convertible Light Vehicles in Rollovers. 26,975 4,135 2,744 1,431
Roof-Involved Rollover...................... 19,803 3,861 1,902 1,110
Some Fixed Object Collision on Top.......... 17,440 3,149 1,644 1,075
Not Totally Ejected......................... 16,608 2,634 949 511
Using Safety Restraints..................... 12,099 1,906 591 160
Outboard Seats.............................. 11,770 1,868 591 160
Roof Component Intrusion.................... 8,669 1,552 471 140
===============================================================
Head, Neck, or Face Injury From Intruding 3,348 712 378 116
Roof Component.............................
Injury--Not MAIS............................ 0 -128 -133 -80
Injury at MAIS--Not Sole Injury............. -1,736 -31 -40 -3
---------------------------------------------------------------
Sole MAIS Injury........................ 1,611 553 205 33
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The most significant exclusions resulted from requirements that
fatalities occurred in rollovers in which (1) the roof was damaged in a
rollover, (2) the damage was not caused by collision with a fixed
object, (3) the fatally injured occupants were not ejected, and (4)
those occupants were belted.
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\4\ Note: The relevant target population used for the estimation
of benefits is identified in the row titled ``Sole MAIS Injury.''
Also, the numbers reflect rounding errors.
\5\ Injury--Not MAIS: This means that the most serious injury
was to a portion of the body other than the head, neck or face.
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It is important to understand what Table 1 indicates about the
safety
[[Page 22352]]
potential of addressing roof crush. Even if there were some way to
prevent every single rollover death resulting from roof crush, the
total lives saved would be 667, not the approximately 10,000 deaths
that result from rollover each year. This is why each initiative in
NHTSA's comprehensive program to address the different aspects of the
rollover problem is so important.
The details of today's rule upgrading roof crush occupant
protection, including costs and benefits and the agency's analysis of
the public comments on our NPRM and SNPRM, are discussed in the rest of
this document.
IV. The Agency's Proposed Rule
a. NPRM
On August 23, 2005, NHTSA published in the Federal Register (70 FR
49223) a NPRM to upgrade FMVSS No. 216, Roof Crush Resistance.\6\ FMVSS
No. 216 seeks to reduce deaths and serious injuries resulting from the
roof being crushed and pushed into the occupant compartment when the
roof strikes the ground during rollover crashes.
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\6\ Docket No. NHTSA-2005-22143.
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Current requirements.
FMVSS No. 216 currently applies to passenger cars, and to
multipurpose passenger vehicles, trucks and buses with a GVWR of 2,722
kilograms (6,000 pounds) or less.
The standard requires that when a large steel test plate (sometimes
referred to as a platen) is placed in contact with the roof of a
vehicle and then pressed downward, simulating contact of the roof with
the ground during a rollover crash, with steadily increasing force
until a force equivalent to 1.5 times the unloaded weight of the
vehicle is reached, the distance that the test plate has moved from the
point of contact must not exceed 127 mm (5 inches). The criterion of
the test plate not being permitted to move more than a specified amount
is sometimes referred to as the ``platen travel'' criterion. Under S5
of the standard, the application of force is limited to 22,240 Newtons
(5,000 pounds) for passenger cars, even if the unloaded weight of the
car times 1.5 is greater than that amount.
Proposed upgrade.
As discussed in the August 2005 NPRM, we developed our proposal to
upgrade roof crush resistance requirements after considerable analysis
and research, including considering comments received in response to a
RFC published in the Federal Register (66 FR 53376) \7\ on October 22,
2001. Prior to publishing the RFC, the agency conducted a research
program to examine potential methods for improving the roof crush
resistance requirements. The agency testing program included full
vehicle dynamic rollover testing, inverted vehicle drop testing, and
comparing inverted drop testing to a modified FMVSS No. 216 test. After
considering the results of the testing and other available information,
the agency concluded that the quasi-static procedure provides a
suitable representation of the real-world dynamic loading conditions,
and the most appropriate one on which to focus our upgrade efforts.
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\7\ Docket No. NHTSA-1999-5572.
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In our August 2005 NPRM, to better address fatalities and injuries
occurring in roof-involved rollover crashes, we proposed to extend the
application of the standard to vehicles with a GVWR of up to 4,536
kilograms (10,000 pounds), and to strengthen the requirements of FMVSS
No. 216 by mandating that the vehicle roof structures withstand a force
equivalent to 2.5 times the unloaded vehicle weight, and to eliminate
the 22,240 Newton (5,000 pound) force limit for passenger cars.
Further, in recognition of the fact that the pre-test distance
between the interior surface of the roof and a given occupant's head
varies from vehicle model to vehicle model, we proposed to regulate
roof strength by requiring that the crush not exceed the available
headroom. Under the proposal, this requirement would replace the
current limit on test plate movement.
The proposed new limit would prohibit any roof component from
contacting the head of a seated 50th percentile male dummy when the
roof is subjected to a force equivalent to 2.5 times the unloaded
vehicle weight. We note that this value is sometimes referred to as the
strength-to-weight ratio (SWR), e.g., a SWR of 1.5, 2.5, and so forth.
We also proposed to:
Allow vehicles manufactured in two or more stages, other
than chassis-cabs, to be certified to the roof crush requirements of
FMVSS No. 220, School bus rollover protection, instead of FMVSS No.
216.
Clarify the definition and scope of exclusion for
convertibles.
Revise the vehicle tie-down procedure to minimize
variability in testing.
To accompany our proposal, we prepared a Preliminary Regulatory
Impact Analysis (PRIA) describing the costs and benefits. We estimated
that, if adopted, the proposal would result in 13-44 fewer fatalities
and 498-793 fewer non-fatal injuries each year. The total estimated
recurring fleet cost was $88 to $95 million. We estimated that
approximately 32 percent of the current vehicle fleet would need
improvements to meet the proposed upgraded requirements.
b. SNPRM
On January 30, 2008, NHTSA published in the Federal Register (73 FR
5484) an SNPRM for our ongoing roof crush resistance rulemaking.\8\ In
that document, we asked for public comment on a number of issues that
might affect the content of the final rule, including possible
variations in the proposed requirements. We also announced the release
of the results of various vehicle tests conducted since the proposal.
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\8\ Docket No. NHTSA-2008-0015.
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In the SNPRM, we noted that we had been carefully analyzing the
numerous comments we had received on the NPRM, as well as the various
additional vehicle tests, including both single-sided tests and two-
sided tests, conducted since the NPRM. We invited comments on how the
agency should factor the new information into its decision. We noted
that while the NPRM focused on a specified force equivalent to 2.5
times the unloaded vehicle weight, the agency could adopt a higher or
lower value for the final rule. We explained, with respect to two-sided
testing, that we believed there was now sufficient available
information for the agency to consider a two-sided requirement as an
alternative to the single-sided procedure described in the NPRM. We
stated that we planned to evaluate both the single-sided and two-sided
testing alternatives for the final rule and requested comments that
would help us reach a decision on that issue.
We also noted in the SNPRM that the agency had conducted additional
analysis concerning the role of vertical roof intrusion and post-crash
headroom in predicting roof contact injuries to the head, neck or face
during FMVSS No. 216 rollovers. At the time of the NPRM, the agency
estimated benefits based on post-crash headroom, the only basis for
which a statistical relationship with injury reduction had been
established. After the NPRM, with additional years of data available, a
statistically significant relationship between intrusion and injury for
belted occupants was established.
c. Congressional Mandate
Section 10301 of SAFETEA-LU generally required the Secretary to
issue
[[Page 22353]]
a final rule upgrading roof crush resistance by July 1, 2008, while
providing for a later date under certain circumstances. That section
provides:
Sec. 10301. VEHICLE ROLLOVER PREVENTION AND CRASH MITIGATION.
(a) In General.--Subchapter II of chapter 301 is amended by
adding at the end the following:
Sec. 30128. Vehicle rollover prevention and crash mitigation
(a) IN GENERAL.--The Secretary shall initiate rulemaking
proceedings, for the purpose of establishing rules or standards that
will reduce vehicle rollover crashes and mitigate deaths and
injuries associated with such crashes for motor vehicles with a
gross vehicle weight rating of not more than 10,000 pounds.
* * * * *
(d) Protection of Occupants.--One of the rulemaking proceedings
initiated under subsection (a) shall be to establish performance
criteria to upgrade Federal Motor Vehicle Safety Standard No. 216
relating to roof strength for driver and passenger sides. The
Secretary may consider industry and independent dynamic tests that
realistically duplicate the actual forces transmitted during a
rollover crash. The Secretary shall issue a proposed rule by
December 31, 2005, and a final rule by July 1, 2008.
The statute provides that if the Secretary determines that the July
1, 2008 deadline for the final rule cannot be met, the Secretary is to
notify Congress and explain why that deadline cannot be met, and
establish a new date. The Secretary provided such notifications to
Congress, and established a date of April 30, 2009.
V. Overview of Comments
NHTSA received comments from a wide variety of interested parties,
including vehicle manufacturers and their trade associations, suppliers
of automobile equipment and a supplier trade association, consumer
advocacy and other organizations, trial lawyers, engineering firms and
consultants, members of academia, elected officials and government
organizations, and private individuals. All of the comments may be
found in the docket for the NPRM or SNPRM. In this section, we provide
a broad overview of the significant comments. Where we identify
specific commenters, we cite representative comments.
General Approach and SWR
Vehicle manufacturers were generally supportive of the agency's
proposal, while recommending a number of specific modifications. They
generally supported a SWR of 2.5, with caveats about sufficient
leadtime and test procedure issues. They expressed concerns about SWRs
higher than 2.5, including potential adverse effects on safety
resulting from increased mass.
Consumer advocacy organizations and a number of other commenters
argued that it is not enough to upgrade the current quasi-static
requirement, and that a dynamic test requirement is needed. While
specific recommendations varied, one was for the agency to adopt an
upgraded quasi-static requirement now, and to proceed with further
rulemaking for a dynamic test.
Advocates for Highway Safety (Advocates) stated that the proposed
quasi-static test cannot demonstrate actual roof crush resistance in
rollover crashes and that a dynamic test would address occupant
kinematics and injury responses in actual rollover crashes. Public
Citizen stated that a dynamic test could simultaneously evaluate the
performance of seat belts, doors, ejection and the roof. A number of
commenters supported specific dynamic tests.
The Center for Auto Safety (CAS) stated that while it strongly
supports a dynamic test, it believes rollover protection can be
dramatically improved with a well-crafted quasi-static test. It argued
that test procedure changes related to roll angle and pitch angle are
needed to ensure that the roof receives appropriate shear stress.
As to the SWR for an upgraded quasi-static test requirement,
consumer advocacy organizations and a number of other commenters argued
that the SWR should be significantly higher than 2.5. Many of these
commenters recommended a SWR of 3.5, with some recommending higher
levels.
The Insurance Institute for Highway Safety (IIHS) submitted a new
study which it said supports increasing the SWR beyond 2.5. It stated
that based on the current evidence, it supports a SWR of 3.0 to 3.5.
Performance Criterion
The agency received a variety of comments on the proposed headroom
reduction criterion. Some commenters, including consumer groups,
supported a headroom reduction criterion but argued that a platen
travel criterion is also needed. Several commenters expressed concern
that, for some vehicles, the proposed headroom reduction criterion
would be less stringent and less protective than the current platen
travel criterion. The agency also received comments recommending that
the agency make these criteria more stringent to protect taller
occupants, e.g., by using a 95th percentile adult male dummy instead of
a 50th percentile adult male dummy to measure headroom and by reducing
the amount of platen travel that is permitted.
Vehicle manufacturers urged the agency to retain the current platen
travel criterion instead of adopting a headroom reduction criterion.
They argued, among other things, that using the headroom reduction
criterion would add unnecessary complexity to the test procedure and
result in problems related to repeatability and practicability. Some
manufacturers stated that if the agency adopts a headroom reduction
criterion, it should adopt a test procedure using a head positioning
fixture instead of a test dummy.
IIHS stated that relating the allowable amount of roof crush in the
quasi-static test to the headroom in specific vehicles is a good
concept but that, in practice, the agency's research tests have not
shown that replacing the 5-inch platen travel criterion with the
headroom requirement would be a meaningful change to the standard and
may not justify the added complications to the test procedure.
Single- or Two-Sided Testing
Several consumer advocacy organizations and other commenters
strongly supported two-sided testing. Public Citizen stated that in a
vast majority of rollover cases, the injured party was typically seated
on the far side, that is, the side of the second impact. It argued that
it is not possible to upgrade FMVSS No. 216 without a two-sided test
requirement.
IIHS stated that while it supports any changes that would increase
the level of roof strength of the vehicle fleet, it has no real-world
data to address the potential benefits of two-sided testing. It stated
that a single-sided test with a higher SWR may be more effective at
promoting robust roof designs than a two-sided test with a lower SWR
requirement.
The comments of vehicle manufacturers were somewhat mixed on the
issue of single- or two-sided testing. The Alliance of Automobile
Manufacturers (Alliance) stated that it believes the agency has
provided insufficient justification for two-sided testing. It stated
that the agency has not provided analysis demonstrating that two-sided
testing relates to real-world safety. The Alliance also expressed
concern that two-sided testing would amplify variability and
repeatability problems.
The Association of International Automobile Manufacturers (AIAM)
stated that based on the information and
[[Page 22354]]
analysis provided by the agency regarding the two-sided test, it
believes that the test shows enough potential to merit further
consideration by the agency. AIAM argued that additional analysis would
be needed before it could provide a preferred regulatory approach, but
indicated that the two-sided approach would more directly address the
multiple roof contact weakening phenomenon.
Leadtime
Vehicle manufacturers argued that a phase-in is needed for the
upgraded roof crush requirements. The Alliance stated that if the final
rule reflected a reasonable accommodation of the issues raised in its
comments, it would be reasonable for a phase-in to begin, with a
compliance percentage of 20 percent, on the first September 1, that
occurred more than 36 months after issuance of the final rule. That
organization stated that it would not be practicable to apply the
upgraded requirements to all new vehicles at once, since far more
vehicle models require redesigns than anticipated by NHTSA. The
Alliance requested a phase-in that incorporates carryforward credits.
It stated that additional leadtime would be necessary if the agency
adopted a head contact criterion instead of platen travel, a two-sided
test or a SWR higher than 2.5.
Costs and Benefits
Many commenters addressed the PRIA, which analyzed the costs and
benefits and other impacts of the proposed rule, and a later discussion
of these impacts included in the SNPRM. Among other things, commenters
addressed the target population, the pass/fail rate of the current
fleet, cost and weight impacts, and estimates of benefits.
Preemption
We received numerous comments on our discussion in the NPRM of the
possible preemptive effect of an upgraded roof crush standard on State
common law tort claims. Vehicle manufacturers and one organization
strongly supported the view that an upgraded roof crush standard would
conflict with and therefore impliedly preempt State rules of tort law
imposing more stringent requirements than the one ultimately adopted by
NHTSA. Consumer advocacy groups, members of Congress and State
officials, trial lawyers, consultants, members of academia, and private
individuals strongly opposed that view. The opposing comments from
State officials included one signed by 27 State Attorneys General and
the National Conference of State Legislatures.
Other Issues
We received comments on many other issues. Commenters addressed a
number of issues concerning the FMVSS No. 216 test procedure, including
the vehicle tie-down procedure, platen angle and size, and whether the
vehicle should be tested with the windshield and/or other glazing in
place. Commenters also addressed requirements for multi-stage vehicles.
June 2008 Congressional Hearing and Letters
On June 4, 2008. the Subcommittee on Consumer Affairs, Insurance,
and Automotive Safety of the Senate Commerce, Science and
Transportation Committee held an oversight hearing on passenger vehicle
roof strength. Former NHTSA Deputy Administrator James Ports testified
at the hearing. At the hearing and also in a subsequent letter to
Secretary Peters dated June 19, 2008, several Senators encouraged the
agency to extend the July 1, 2008 date for completing a final rule.
They encouraged the agency to ensure a rulemaking that would maximize
vehicle safety and significantly reduce deaths and injuries for drivers
and passengers in vehicle rollover crashes.
Several Senators encouraged NHTSA to consider a two-sided test
requirement and a higher SWR requirement than the proposed 2.5 level,
and to provide detailed information concerning alternatives considered
by the agency. They also raised concerns about the use of 50th
percentile adult male test dummies instead of ones representing taller
occupants. The Senators also expressed significant concerns about
possible preemption of common law tort actions, and asked that such a
provision not be included in the final rule.
In a letter to Secretary Peters dated June 27, 2008, Chairman Henry
Waxman of the House Committee on Oversight and Government Reform,
raised similar concerns to those of the Senators.
New IIHS Roof Strength Consumer Information Program
On February 19, 2009, IIHS met with NHTSA representatives to
provide the agency information about a new roof strength consumer
information program that the organization is initiating. IIHS believes
the FMVSS No. 216 test procedure is a meaningful structural assessment
of real-world rollover crashworthiness as shown by recent studies it
has conducted showing that improved roof strength reduces injury risk
in midsize SUVs and small cars. That organization indicated that the
boundary for a good rating in the IIHS program will be a SWR of 4.0 in
a one-sided platen test similar to the existing FMVSS No 216 test
procedure. IIHS indicated that it does not plan to rate the larger,
heavier light vehicles, i.e., ones likely to have GVWRs greater than
2,722 kilograms (6,000 pounds).
On March 24, 2009, IIHS issued a press release announcing a number
of details about its new rating system, including ratings for 12 small
SUVs. For an acceptable rating, the minimum SWR is 3.25. A marginal
rating value is 2.5. Anything lower than that is rated as poor. In
order to earn IIHS's ``top safety pick'' award for 2010, vehicles will
need to have a good roof strength rating, i.e., SWR of 4.0. Of the 12
small SUVs tested by IIHS, eight were rated by that organization as
good, five as acceptable, two as marginal, and one as poor.
VI. Agency Decision and Response to Comments
a. Primary Decisions
1. Basic Nature of the Test Requirements--Quasi-Static vs. Dynamic
Tests
As noted above and discussed in detail in the NPRM, we developed
our proposal to upgrade roof crush resistance requirements after
considerable analysis and research, including conducting a research
program to examine potential methods for improving the roof crush
resistance requirements. The agency testing program included full
vehicle dynamic rollover testing, inverted vehicle drop testing, and
comparing inverted drop testing to a modified FMVSS No. 216 test. After
considering the results of the testing and other available information,
the agency concluded that the quasi-static procedure provides a
suitable representation of the real-world dynamic loading conditions,
and the most appropriate one on which to focus our upgrade efforts.
We did not propose a dynamic test procedure in either the NPRM or
the SNPRM. We did discuss in the NPRM a number of types of dynamic
tests and why we were not including them in the proposal. We stated our
belief that the current quasi-static test procedure is repeatable and
capable of simulating real-world deformation patterns. We also stated
that we were unaware of any dynamic test procedure that provides a
sufficiently repeatable test environment.
Consumer advocacy organizations and a number of other commenters
argued that it is not enough to upgrade the current quasi-static
requirement, and
[[Page 22355]]
that a dynamic test requirement is needed. While specific
recommendations varied, one was for the agency to adopt an upgraded
quasi-static requirement now, and to proceed with further rulemaking at
this time for a dynamic test.
Advocates stated that the proposed quasi-static test cannot
demonstrate actual roof crush resistance in rollover crashes and that a
dynamic test would address occupant kinematics and injury responses in
actual rollover crashes. Public Citizen stated that a dynamic test
could simultaneously evaluate the performance of seat belts, doors,
ejection mitigation and the roof. A number of commenters made specific
recommendations concerning the type of dynamic test that the agency
should propose, e.g., with a number recommending the FMVSS No. 208
dolly test and/or the Jordan Rollover System (JRS) test.
As part of our considering the merits of a dynamic test and
comments on the JRS, on February 23, 2007, NHTSA representatives met
with Xprts, LLC (Xprts) at its test facility in Goleta, CA, to view and
discuss the device. CAS and Center for Injury Research (CFIR) also
submitted additional test data to the agency using the JRS.
We note that the agency is also aware of tests used by
manufacturers to assess a vehicle's rollover performance during vehicle
development and conditions they are designed to represent such as the
curb trip, soil trip, the bounce over, etc.\9\
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\9\ Viano D., Parenteau C., ``Rollover Crash Sensing and Safety
Overview,'' SAE International, 2004-01-0342.
---------------------------------------------------------------------------
As noted earlier in this document, rollover crashes are complex and
chaotic events. Rollovers can range from a single quarter turn to eight
or more quarter turns, with the duration of the rollover crash lasting
from one to several seconds. The wide range of rollover conditions
occurs because these crashes largely occur off road where the vehicle
motion is highly influenced by roadside conditions.
The variety and complexity of real-world rollover crashes create
significant challenges in developing dynamic tests suitable for a
Federal motor vehicle safety standard. Rollover crash tests can have an
undesirable amount of variability in vehicle and occupant kinematics.
In assessing whether a potential dynamic test would be appropriate
for a Federal motor vehicle safety standard, the agency must consider
such issues as (1) whether the test is representative of real-world
crashes with respect what happens to the vehicle and any specified test
dummies; (2) for the specific aspect of performance at issue, whether
the test is sufficiently representative of enough relevant real-world
crashes to drive appropriate countermeasures and, if not, the number
and nature of necessary tests to achieve that purpose; (3) whether the
test is repeatable and reproducible so that the standard will be
objective; and (4) whether the test dummies to be specified are
biofidelic for the purposes used.
We have reviewed the comments recommending a dynamic test and are
including our analysis of those comments in an appendix to this
document. NHTSA appreciates the information and data that have been
provided on this subject. We decline, however, to pursue a dynamic test
as part of this rulemaking, or to initiate at this time a separate
rulemaking for a dynamic test.
As noted above, we explained in the NPRM that we were unaware of
any dynamic test procedure that provides a sufficiently repeatable test
environment. After reviewing the public comments and for reasons
discussed in the appendix, we continue to take that position. While
some commenters argued that certain procedures are repeatable, the
agency was not persuaded by the arguments and data they presented.
Moreover, for reasons discussed in the appendix, there are significant
issues associated with each of the cited dynamic test procedures
related to possible use in a Federal motor vehicle safety standard.
Also of importance for this rulemaking, even if NHTSA were to
identify a particular dynamic test procedure, among the many known to
be available, as likely to be suitable for assessing roof crush
resistance (something we have not been able to do thus far), we would
need additional years of research to evaluate and refine, as necessary,
the procedure to develop a proposal, including evaluating it in the
context of the current vehicle fleet. It is also not known whether any
dynamic test requirement that might be identified by NHTSA's research
would produce significant additional benefits beyond those that will be
produced by the substantial upgrade of the quasi-static procedure that
we are adopting in this rule.
NHTSA agrees, however, with pursuing a dynamic test as our ultimate
goal. We would like to have one for rollover crashes just as we do for
front and side crashes. Unfortunately, we cannot adopt or even propose
one now because of issues related to test repeatability, a dummy, and
lack of injury criteria. We are pursuing further research for a dynamic
test, but we expect that it will take a number of years to resolve
these issues. In the meantime, we do not want to delay a significant
upgrade of FMVSS No. 216 that will save 135 lives each year.
2. Vehicle Application
FMVSS No. 216 currently applies to passenger cars, and to
multipurpose passenger vehicles, trucks and buses with a GVWR of 2,722
kilograms (6,000 pounds) or less. In our August 2005 NPRM, in addition
to proposing upgraded performance requirements, we proposed to extend
the application of the standard to vehicles with a GVWR of up to 4,536
kilograms (10,000 pounds). We proposed to permit vehicles manufactured
in two or more stages, other than chassis-cabs, to be certified to the
roof crush requirements of FMVSS No. 220, instead of FMVSS No. 216. We
stated that we believed that the requirements of FMVSS No. 220 appeared
to offer a reasonable avenue to balance the desire to respond to the
needs of multi-stage manufacturers and the need to increase safety in
rollover crashes.
The commenters generally supported extending the application of
FMVSS No. 216 to vehicles with a GVWR of up to 4,536 kilograms (10,000
pounds). The National Transportation Safety Board (NTSB) stated that
heavier vehicles such as 12- and 15-passenger vans, not currently
subjected to the standard, are experiencing patterns of roof intrusion
greater than vehicles already subject to the requirements. That
commenter also cited two investigations it conducted concerning the
safety need for vehicles between 6,000 and 10,000 pounds GVWR to meet
roof crush resistance requirements.
We received a number of comments concerning requirements for multi-
stage vehicles and vehicles with altered roofs, including ones from
Advocates, the National Truck Equipment Association (NTEA), the
Recreation Vehicle Industry Association (RVIA) and the National
Mobility Equipment Dealers Association (NMEDA). The concerns and
recommendations of these commenters varied considerably. We discuss and
address the comments later in this document. For purposes of this more
general section concerning applicability, we note that we are providing
a FMVSS No. 220 option for some but not all multi-stage vehicles and
for vehicles which are altered in certain ways to raise the height of
the roof. We also note that, for reasons discussed in that section, we
are excluding a narrow
[[Page 22356]]
category of multi-stage trucks from FMVSS No. 216 altogether.
Subject to the limited exceptions/alternatives/exclusions noted in
the previous paragraph or already included in FMVSS No. 216, and for
the reasons discussed in the NPRM and in this document, we are
extending the application of the standard to vehicles with a GVWR of up
to 4,536 kilograms (10,000 pounds).\10\
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\10\ This final rule will address the NTSB's recommendation H-
03-16, to include 12- and 15-passenger vans in FMVSS No. 216, to
minimize the extent to which survivable space is compromised in the
event of a rollover accident.
---------------------------------------------------------------------------
3. Single-Sided or Two-Sided Tests
Under the current version of FMVSS No. 216, vehicles must meet the
standard's requirements for both the driver and passenger sides of the
vehicle. Thus, roof crush resistance protection is required for both
the driver and passenger sides of the vehicle. The standard specifies a
single-sided test. While a vehicle must meet the standard's test
requirements, regardless of whether it is tested on the driver or
passenger side, a particular vehicle is tested on only one side.
As discussed in the NPRM, a number of commenters on our 2001 RFC
suggested that the agency specify a two-sided test requirement, i.e., a
requirement that each vehicle must meet the standard's test
requirements when tested sequentially, first on one side of the
vehicle, and then on the other side. Commenters making this
recommendation included Public Citizen and CFIR. The commenters stated
that vehicle occupants on the far side of the rollover have a much
greater risk of serious injury than occupants on the near side,\11\ and
argued that a two-sided requirement is needed to protect far side
occupants.
---------------------------------------------------------------------------
\11\ Near side is the side toward which the vehicle begins to
roll and the far side is the trailing side of the roll.
---------------------------------------------------------------------------
In the NPRM, the agency summarized the results of six two-sided
tests it had conducted in light of those comments. The testing sought
to evaluate the strength of the second side of the roof of vehicles
whose first side had already been tested. In this testing, after the
force was applied to one side of the roof over the front seat area of a
vehicle, the vehicle was repositioned and force was then applied on the
opposite side of the roof over the front seat area. In performing these
tests on both sides of a vehicle, the agency used the platen angle
currently specified in FMVSS No. 216 (5 degree pitch forward and 25
degree rotation outward, along its lateral axis). We concluded that the
strength of the roof on the second side of some vehicles may have been
increased or decreased as a result of the deformation of the first side
of the roof. The agency indicated that it planned to conduct further
research before proposing rulemaking in this area.
In commenting on the NPRM, a number of consumer advocacy
organizations and other commenters strongly supported a two-sided test
requirement. These commenters included, among others, Public Citizen,
CFIR, CAS, and Advocates. Supporters of a two-sided test requirement
argued that more damage occurs to the far (or trailing) side of the
vehicle in a rollover crash, and a two-sided test would better reflect
this real-world intrusion. They further argued that when the near side
roof and windshield are compromised in a rollover, the far side will
not be able to withstand the forces of the event, and, consequently,
facilitate roof collapse. ARCCA, Inc., Consumers Union, and Safety
Analysis and Forensic Engineering (SAFE) suggested a two-sided test
would simulate the impact that occurs in the majority of rollover
incidents.
In light of the substantial interest in a two-sided test
requirement, NHTSA expanded the series of two-sided roof crush tests
discussed in the NPRM. In our January 2008 SNPRM, we explained that we
had, by that time, conducted a total of 26 sequential two-sided tests,
and announced that we were releasing these data to the public in
conjunction with the SNPRM.
We stated in the SNPRM that the two-sided test results showed the
first side test generally produces a weakening of the structure. This
was shown by the fact that the recorded SWR for the second side was
generally lower than for the first side. On average, the peak strength
for the second side was reduced by 8.7 percent. However, for several of
the vehicles, we observed considerably higher reductions in peak
strength. Of the 26 vehicles that had been tested by that time,
excluding the Chevrolet Express, six experienced reductions in strength
of 19 percent or greater. We excluded the Chevrolet Express because of
a test anomaly.\12\
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\12\ Between the first and second side tests, the front door on
the tested side was opened. Because of damage to the vehicle during
the first side test, the door would not properly close. The door was
clamped until the latch engaged, locking the door in place. This may
have compromised the structural integrity of the roof and reduced
the measured peak load on the second side.
---------------------------------------------------------------------------
With respect to two-sided vehicle testing, we stated that we
believed that the post-NPRM tests provided the agency with sufficient
additional information for the agency to consider a two-sided test
requirement for the final rule. We stated that we would evaluate both
the single-sided and two-sided testing alternatives for the final rule,
and requested comments to help us reach a decision on that issue.
Comments
In commenting on the SNPRM, a number of consumer advocacy
organizations continued to strongly support a two-sided test
requirement. Public Citizen stated that in a vast majority of rollover
cases, the injured party was typically seated on the far side, that is,
the side of the second impact. It argued that it is not possible to
upgrade FMVSS No. 216 without a two-sided test requirement. Some
commenters argued, as they had in commenting on the NPRM, that they
believe SAFETEA-LU requires a two-sided test.
IIHS stated that while it supports any changes that would increase
the level of roof strength of the vehicle fleet, it has no real-world
data to address the potential benefits of two-sided testing. It stated
that a single-sided test with a higher SWR may be more effective at
promoting robust roof designs than a two-sided test with a lower SWR
requirement.
The Alliance stated that it believes the agency has provided
insufficient justification for two-sided testing. It stated that the
agency has not provided analysis demonstrating that two-sided testing
relates to real-world safety.
The Alliance also expressed concern that two-sided testing would
amplify variability and repeatability problems. That organization
argued that the agency's limited repeatability testing for a potential
two-sided requirement indicates poor repeatability in SWR between the
first and second side tests for the same vehicle. The Alliance cited
agency tests of the Lincoln LS and Buick LaCrosse.
According to the Alliance, these differences may be due solely to
lack of test procedure repeatability and test lab reproducibility,
rather than any real weakening or strengthening of the roof structure
due to the first side test. That commenter stated that in a two-sided
scenario, the deformed shape of a vehicle tested for roof strength on
one side between any two tests is not identical. The starting point for
the roof-strength testing on the second side is therefore, according to
the Alliance, inherently different and results in substantial
variability in measured roof strength.
AIAM stated that based on the information and analysis provided by
[[Page 22357]]
the agency regarding the two-sided test, it believes that the test
shows enough potential to merit further consideration by the agency.
AIAM argued that additional analysis would be needed before it could
provide a preferred regulatory approach, but indicated that the two-
sided approach would more directly address the multiple roof contact
weakening phenomenon.
Agency Response
After carefully considering the comments and available information,
we have decided, for the reasons discussed below, to adopt a two-sided
test requirement.
In responding to the comments, we begin by addressing the argument
raised by some commenters that SAFETEA-LU requires a two-sided test.
Public Citizen stated that the agency has ``ignored the express
requirement of a two-sided test.'' That organization cited the
statutory language requiring NHTSA to upgrade FMVSS No. 216 related to
roof strength ``for driver and passenger sides.'' (Emphasis added by
Public Citizen.)
As discussed earlier in this document, under the current version of
FMVSS No. 216, vehicles must meet the standard's requirements for both
the driver and passenger sides of the vehicle, i.e., a vehicle must
meet the standard's test requirements regardless of whether it is
tested on the driver or passenger side. Thus, while the standard
specifies a single-sided test, roof crush resistance protection is
required for both the driver and passenger sides of the vehicle.
Similarly, upgrading the current performance requirements so that
vehicles must provide protection at a significantly higher SWR under a
single-sided test procedure would result in upgraded protection for
both the driver and passenger sides. Thus, while we understand the
safety arguments raised by Public Citizen and other commenters favoring
a two-sided test, we believe that the language in SAFETEA-LU does not
mandate a two-sided test requirement, only that upgraded protection be
provided for both the driver and passenger sides.
We also note that the issue of whether to adopt a two-sided test is
related to the decision of what stringency to adopt. For any baseline
single-sided test requirement at a particular SWR, either increasing
the SWR for the single-sided test or adding a two-sided test
requirement at the same SWR would represent an increase in stringency.
Therefore, in reaching a decision on these issues, we have considered
them together.
To help evaluate the merits of a two-sided test requirement, the
agency analyzed 1997 through 2006 NASS-CDS rollover crash data,
involving restrained occupants.\13\ Only vehicles that overturned and
experienced 2 or more quarter turns were included. This study included
4,030 NASS-CDS investigated vehicles, and excluded convertibles and
vehicles that had a concentrated loading due to a collision between a
fixed object (pole or tree) and the roof.
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\13\ See report Evaluation of 2 Side Roof Crush Testing placed
in the docket with this notice.
---------------------------------------------------------------------------
The data were analyzed for differences in injury risk for the near
and far side occupants and also to ascertain any disparity in the
amount of roof intrusion. For all rollovers involving two or more
quarter turns, the data showed that there are a similar number of near
and far side occupants involved in the event. A further review of the
injury outcomes showed that the injuries to far side occupants occur at
a slightly higher frequency than injuries to near side occupants.
The occupant injury data were further analyzed to determine whether
the relative proportion of near and far side injured occupants varied
with the amount of roof intrusion. The injury outcomes for occupants in
vehicles with less than 12 cm (5 inches) of near side roof intrusion
show higher frequency of injury for the far side occupant at the
various injury levels. The outcomes for injured occupants in vehicles
with 12 cm (5 inches) or greater near side intrusion have similar
percentages of severe injuries between near and far occupants. Based on
this analysis, the data indicate there may be some higher risk for far
side occupants at lower levels of intrusion; however, none of the
results was statistically significant.
The analysis investigated the difference in roof intrusion between
the near and far side of the vehicle that experienced two quarter turns
or more. For the 4,030 NASS-CDS vehicles, there was a weighted average
maximum vertical intrusion of 7.9 cm (3.1 inches) on the near side and
10.9 cm (4.3 inches) on the far side of the rollover-involved vehicle.
The far side of the vehicle averaged 3 cm (1.2 inches) more vertical
intrusion than the near side.
The analysis also investigated the intrusion difference between the
near and far side grouped by the severity of the rollover. (Severity of
the rollover was defined by single or multiple roof-to-ground
contacts). The data showed a 3 cm (1.2 inch) bias toward the far side
intrusion, independent of the severity of the rollover. For example,
vehicles experiencing five or more quarter turns had 9.2 cm (3.6
inches) of near-side intrusion compared to 12.2 cm (4.8 inches) of far-
side intrusion. The analysis concluded for crashes with multiple roof-
to-ground contacts (or severe rollovers), there is a statistically
insignificant bias on the far side.
Since the publication of the SNPRM, the agency has conducted an
additional five tests \14\ as part of its evaluation, for a total of 31
two-sided tests.\15\ The test results for all 31 two-sided tests are
summarized in Appendix B of this document.
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\14\ The test reports for the additional vehicle tests conducted
by NHTSA are being made available to the public through the agency's
internet vehicle crash test database. We are placing a memorandum in
the docket which provides the Web address for that database and
lists the vehicle models and test numbers that are needed to
reference the information in the database. The agency incorporates
by reference these test reports as part of the record for this
rulemaking.
\15\ We note that we also conducted a test of a Smart ForTwo.
However, we did not include these test results as part of our
evaluation because the vehicle is not typical of a significant
number of vehicles in the fleet.
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On average, the peak strength for the second side was reduced by
8.4 percent. This reduction in strength is consistent with our NASS-CDS
analysis, showing a slight increase of intrusion on the second side.
This also may explain the increased risk to injury for far side
occupants. In all the tests, the windshield fractured during the first
side test and there was not a catastrophic collapse of the roof on the
second side.
In general, there was a good correlation in peak strength between
the first and second side. The agency did test four vehicles that
resulted in increased strength on the second side. However, for several
of the vehicles, we observed considerably higher reductions in peak
strength. Of the 31 vehicles tested, again excluding the Chevrolet
Express, seven experienced reductions in strength of 19 percent or
greater. The two-sided testing conducted by NHTSA indicated an average
difference of approximately 7.1 percent lower peak force for the second
side in vehicles under 2,722 kilograms (6,000 pounds) GVWR and 14.9
percent lower peak force for the second side in vehicles over 2,722
kilograms (6,000 pounds) GVWR.
We have decided to adopt a two-sided test in light of several
considerations. First, we believe a two-sided test is more
representative of the higher severity rollover crashes in which a
vehicle experiences multiple quarter turns. In such crashes, the
vehicles sometimes experiences a significant impact on one side of the
vehicle and,
[[Page 22358]]
as the vehicle continues to turn, another significant impact on the
other side of the vehicle. A two-sided test will help ensure that the
impact on the first side of the vehicle does not cause excess damage
that will prevent the vehicle from providing protection during the
impact on the second side of the vehicle.
Moreover, as discussed in the FRIA, the greater stringency
associated with a two-sided test requirement will provide greater
benefits.
While we recognize that a two-sided test requirement affects the
stringency of the standard, as compared to a single-sided test
requirement at the same SWR, we believe that it does not raise concerns
related to test procedure repeatability and test lab reproducibility.
In addressing this issue, we note that the test conducted on the
second side is identical to the test conducted on the first side. Thus,
the second side test by itself is repeatable and reproducible, for the
same reasons the first side test is repeatable and reproducible.
As noted by the Alliance, the ``starting point'' for the second
side test is different than for the first side test in that the vehicle
may have experienced damage during the first side test. However, it is
the purpose of a two-sided test requirement to limit such damage, to
the extent such damage would prevent compliance with the standard's
performance requirements during the second side test.
As to the Lincoln LS and Buick Lacrosse repeat tests cited by the
Alliance, the change in peak SWR between the first and second side test
was -21.3 percent and -8.7 percent for the two Lincoln LS vehicles
tested, and -13.5 percent and -3.4 percent for the two Buick Lacrosse
vehicles tested. For the Lincoln LS, there was good correlation between
the load-deformation curves on the first side in the two tests.
However, on the second side, the load-deformation curves diverge prior
to the peak SWR. Further, in one Lincoln LS test, the second side
correlated well with the first side. The other test did not show the
same correlation on the second side, which led us to believe internal
structural damage to the roof during the first side test was the cause.
With respect to the Buick Lacrosse, the agency identified a pre-test
windshield crack as the likely reason for the difference in outcome
between the two tests. The load-deformation curves for the first side
did not reach the same peak load; however, there is good correlation on
the second side. Thus, we believe the differences relate to vehicle
performance instead of test procedure issues.
It is important to note that the Lincoln LS and Buick Lacrosse
vehicles were not subject to an FMVSS incorporating a two-sided
requirement or an SWR requirement above 1.5, so they were not designed
to meet such a requirement (two-sided test requirement at the tested
SWR). Manufacturers can ensure that a vehicle meets a two-sided test
requirement by designing it so that they will be able to meet the
second-side test despite whatever damage may occur in the first side
test. As a general matter, the greater the structural damage that
occurs in the first-side test, the greater the variability one would
expect in the second-side test. We note that the performance
requirement is not expressed in terms of the percentage difference in
damage between the first-side test and the second test; instead, the
vehicle must meet the same specified performance criteria in both
tests. We also note that the first-side test is conducted only up to
the SWR specified in the standard.
Finally, we note that issues raised by commenters concerning
varying platen angle and size for the second-side test are addressed
later in this document in the section addressing aspects of the test
procedure.
4. Upgraded Force Requirement--Specified Strength to Weight Ratio (SWR)
As discussed earlier, FMVSS No. 216 currently requires that the
lower surface of the test platen not move more than 127 mm (5 inches),
when it is used to apply a force equal to 1.5 times the unloaded
vehicle weight to the roof over the front seat area. In the NPRM, the
agency proposed to require that the roof over the front seat area
withstand a force increase equal to 2.5 times the unloaded weight of
the vehicle, and to eliminate the 22,240 Newton (5,000 pound) force
limit for passenger cars.
NHTSA explained that it believes that FMVSS No. 216 could protect
front seat occupants better if the applied force requirement reduced
the extent of roof crush occurring in real world crashes. That is, the
increased applied force requirement would lead to stronger roofs and
reduce the roof crush severity observed in real world crashes. We
observed that in many real-world rollovers, vehicles subject to the
requirements of FMVSS No. 216 experienced vertical roof intrusion
greater than the test plate movement limit of 127 mm (5 inches).
In explaining the proposed 2.5 value for SWR, the agency noted that
it previously conducted a study \16\ (Rains study) that measured peak
forces generated during quasi-static testing under FMVSS No. 216 and
under Society of Automotive Engineers (SAE) J996 inverted drop testing.
In the Rains study, nine quasi-static tests were first conducted. The
energy absorption was measured and used to determine the appropriate
corresponding height for the inverted drop conditions. Six of the
vehicles were then dropped onto a load plate. The roof displacement was
measured using a string potentiometer connected between the A-pillar
and roof attachment and the vehicle floor. The peak force from the drop
tests was limited to only the first 74 mm (3 inches) of roof crush
because some of the vehicles rolled and contacted the ground with the
front of the hood. Similarly, the peak quasi-static force was limited
during the first 127 mm (5 inches) of plate movement.
---------------------------------------------------------------------------
\16\ Glen C. Rains and Mike Van Voorhis, ``Quasi Static and
Dynamic Roof Crush Testing,'' DOT HS 808-873, 1998.
---------------------------------------------------------------------------
This report showed that for the nine quasi-static tests, the peak
force-to-weight ratio ranged from 1.8 to 2.5. Six of these vehicle
models were dropped at a height calculated to set the potential energy
of the suspended vehicle equal to the static tests. For these dynamic
tests, the peak force-to-weight ratio ranged from 2.1 to 3.1. In sum,
the agency tentatively concluded that 2.5 was a good representation of
the observed range of peak force-to-weight ratio.
As to eliminating the 22,240 Newton force limit for passenger cars,
the agency noted that the limit was included when the standard was
first issued. The effect of the limit was that passenger cars weighing
more than 1,512 kilograms (3,333 pounds) were subjected to less
stringent requirements. The purpose of the limit was to avoid making it
necessary for manufacturers to redesign large cars that could not meet
the full roof strength requirements of the standard.\17\ At the time,
the agency believed that requiring larger passenger cars to comply with
the full (1.5 times the unloaded vehicle weight) requirement would be
unnecessary because heavy passenger cars had lower rollover propensity.
However, as discussed in the NPRM, the agency tentatively concluded
that occupants of passenger cars weighing more than 1,512 kilograms
(3,333 pounds) are sustaining rollover-related injuries and that those
cars should be able to comply with the proposed requirements.
---------------------------------------------------------------------------
\17\ See 54 FR 46276.
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[[Page 22359]]
The agency stated in the NPRM that it believed that manufacturers
would comply with the upgraded standard by strengthening reinforcements
in roof pillars, by increasing the gauge of steel used in roofs or by
using higher strength materials.
In the SNPRM, we noted that we had been carefully analyzing the
numerous comments received in response to the proposal, and the various
additional vehicle tests conducted after publication of the NPRM. We
invited comments on how the agency should factor in this new
information into its decision. We stated that while the NPRM focused on
a specified force equivalent to 2.5 times the unloaded vehicle weight,
the agency could adopt a higher or lower value for the final rule.
In the SNPRM, we observed from the recent vehicle testing (focusing
on the single-sided test results) that the range of SWRs for vehicles
with a GVWR of 2,722 kilograms (6,000 pounds) or less tended to be
higher than the range of SWRs for vehicles with a GVWR greater than
2,722 kilograms (6,000 pounds). The SWR of many late model vehicles
with a GVWR of 2,722 kilograms (6,000 pounds) or less was substantially
higher than the 2.5 value the agency focused on in the NPRM.
Conversely, only two vehicles we tested with a GVWR greater than 2,722
kilograms (6,000 pounds) exceeded the 2.5 value.
We noted in the SNPRM that the PRIA had examined the proposed SWR
of 2.5 and the alternative SWR of 3.0 times the unloaded vehicle
weight. The agency included in the SNPRM discussion and analysis
concerning a number of factors expected to change the estimated
impacts, and sought comments concerning impacts of SWR levels of 2.5,
3.0 and 3.5.
Comments on the NPRM
In general, vehicle manufacturers supported an SWR of 2.5, while
safety advocacy groups recommended a more stringent standard with the
majority supporting a 3.5 SWR requirement.
Vehicle manufacturers, including General Motors Corporation (GM),
Ford Motor Company (Ford), DaimlerChrysler Corporation,\18\ Porsche
Cars North America (Porsche), Toyota Motor North America (Toyota), and
Nissan North America (Nissan), and the Alliance supported the proposed
2.5 SWR level, with caveats about sufficient leadtime and other
requested changes to the test procedure, but expressed concern about
raising the SWR further. The Alliance cautioned against increasing the
SWR beyond 2.5 due to the potential adverse effects of increased mass.
It stated that recommendations in the docket for higher levels did not
attempt to account for the potential effect on the static stability
factor (SSF) of adding structure necessary to comply with higher
standards.
---------------------------------------------------------------------------
\18\ In August 2007, Daimler and Chrysler separated. All
comments submitted to the agency prior to that date will be noted in
this document as DaimlerChrysler. Mercedes-Benz USA and Chrysler LLC
submitted comments separately afterwards and will be referenced
accordingly.
---------------------------------------------------------------------------
Commenters supporting a 3.5 SWR included Lipsig, Shapey, Manus &
Moverman (LSMM), Consumers Union, Center for the Study of Responsive
Law (CSRL), Mr. Sances, Perrone Forensic Consulting (Perrone), Ms.
Lawlor, Mr. Clough, Xprts, Mr. Nash, Mr. Friedman, and Forensic
Engineering (FEI). Consumers Union, LSMM, Ms. Lawlor, Mr. Clough, and
Mr. Sances supported a 3.5 SWR based on, among other things, the
performance of the Volvo XC90. Commenters stated that the Volvo XC90
has heightened roof strength resistance through light-weight materials
making it possible to avoid any unnecessary increases in vehicle weight
which could adversely affect rollover propensity. In supporting more
stringent roof crush resistance requirements, the CSRL stated that
NHTSA should consider using its technology-forcing authority.
Several commenters supported an SWR of 4.0 or higher. These
commenters included Mr. Slavik, ARCCA, Technical Services, and FEI. The
commenters suggested that higher strength steel alloy, changes to the
cross sectional thickness of roof components, and other design changes
would make increasing the SWR feasible and cost effective.
In connection with arguments that the agency should base the level
of the standard on the performance of the Volvo XC90, Ford commented
that in considering the stringency of an SWR requirement, roof SWR does
not discriminate vehicles by roof strength. It noted that the roof
strength required to achieve a specific SWR depends on the vehicle's
unloaded vehicle weight (UVW). Ford stated that two vehicles with the
same SWR, but different UVWs, may have roof strength levels that are
actually several thousand pounds apart. That company argued that the
agency's 2.5 SWR proposal is very stringent. Ford stated that vehicle
roof designs are essentially the same for all passenger carrying
vehicles, and that A pillars are A pillars and B pillars are B pillars,
regardless of vehicle type, i.e., the constraints on a roof system
design are applicable to all affected vehicles. That company argued
that because a particular vehicle can achieve a roof SWR of 3.5,
because it has a lower UVW as compared to a full size pickup, does not
mean that 3.5 should be the regulatory requirement.
Comments on the SNPRM
In commenting on the SNPRM, vehicle manufacturers continued to
support an SWR of 2.5, with safety advocacy groups recommending a more
stringent requirement.
The Alliance recommended that all vehicles should be held to the
same requirements and that a separate requirement should not be
afforded for heavy vehicles. Mercedes-Benz suggested that, for a two-
sided test requirement, the SWR on the second side should be lower than
what would be required for the first side. This would reflect the lower
force levels in a rollover that it said the second side would
experience.
IIHS supported raising the SWR to 3.0 or higher in a one-sided
test. IIHS stated that its new analysis justifies such a requirement.
Agency Decision and Response
After carefully considering the comments and available information,
and for the reasons discussed below, we have decided to adopt an SWR
requirement of 3.0 for vehicles with a GVWR of 2,722 kilograms (6,000
pounds) or less, and 1.5 for vehicles with a GVWR greater than 2,722
kilograms (6,000 pounds).
While this rulemaking involves a number of key decisions, the
selection of an SWR requirement is the most important one for both
costs and benefits. Our analysis, presented in detail in the FRIA,
shows that for the alternatives we evaluated, benefits in terms of
reduced fatalities continue to rise with higher SWR levels due to
reduced intrusion. The benefits continue to rise because, for vehicles
designed to have higher SWR levels, the vehicle roofs experience less
intrusion in higher severity crashes. However, costs also increase
substantially with higher SWR levels, so NHTSA must select the
appropriate balance of safety benefits to added costs.
Under the Safety Act, NHTSA must issue safety standards that are
both practicable and meet the need for motor vehicle safety. 49 U.S.C.
30111(a). The agency considers economic factors, including costs, as
part of ensuring that standards are reasonable, practicable, and
appropriate.
In Motor Vehicle Manufacturers Association v. State Farm, 463 U.S.
29, 54-55 (1983), the Supreme Court indicated that the agency must, in
making decisions about safety
[[Page 22360]]
standards, consider reasonableness of monetary and other costs
associated with the standard. It stated, however, that ``(i)n reaching
its judgment, NHTSA should bear in mind that Congress intended safety
to be the preeminent factor under the Motor Vehicle Safety Act:''
The Committee intends that safety shall be the overriding
consideration in the issuance of standards under this bill. The
Committee recognizes * * * that the Secretary will necessarily
consider reasonableness of cost, feasibility and adequate leadtime.
S. Rep. No. 1301, at 6, U.S. Code Cong. & Admin. News 1966, p. 2714.
In establishing standards the Secretary must conform to the
requirement that the standard be practicable. This would require
consideration of all relevant factors, including technological
ability to achieve the goal of a particular standard as well as
consideration of economic factors. Motor vehicle safety is the
paramount purpose of this bill and each standard must be related
thereto. H.Rep. No. 1776, at 16.
Thus, in making our decision concerning SWR, we are guided by the
statutory language, legislative history, and the Supreme Court's
construction of the Safety Act, as well as by the specific requirement
in SAFETEA-LU for us to upgrade FMVSS No. 216 relating to roof strength
for driver and passenger sides for motor vehicles with a GVWR of not
more than 4,536 kilograms (10,000 pounds). We consider both costs and
benefits, bearing in mind that Congress intended safety to be the
preeminent factor under the Safety Act.
As indicated above, while benefits continue to rise with higher SWR
levels, costs also increase substantially. The challenge is to push to
a level where the safety benefits are still reasonable in relation to
the associated costs. As part of this, we consider issues related to
cost effectiveness. The agency's analysis of cost effectiveness is
presented in the FRIA and summarized in this document.
Another important factor in the selection of the SWR requirements
is that there are much higher costs relative to benefits associated
with any level SWR requirement for vehicles with a GVWR greater than
2,722 kilograms (6,000 pounds) as compared to the lighter vehicles
currently subject to the standard.
There are a number of reasons for this differential between heaver
and lighter vehicles. The absolute strength needed to meet a specific
SWR is a function of the vehicle's weight. By way of example, to meet a
2.0 SWR, a vehicle that weighs 1,360 kilograms (3,000 pounds) must have
a roof structure capable of withstanding 26,690 N (6,000 pounds) of
force, while a vehicle that weighs 2,268 kilograms (5,000 pounds) must
have a roof structure capable of withstanding 44,482 N (10,000 pounds)
of force. This means more structure or reinforcement are needed for the
heavier vehicle, which means more cost and weight. Moreover, vehicles
in the heavier category have not previously been subject to FMVSS No.
216, so they have not been required to meet the existing 1.5 SWR
single-sided requirement.
At the same time, these heavier vehicles account for only a very
small part of the target population of occupants who might benefit from
improved roof strength. Only 5 percent of the fatalities in the overall
target population (33 in terms of a specific number) occur in vehicles
over 2,722 kilograms (6,000 pounds) GVWR. Ninety-five percent of the
fatalities (635 in terms of a specific number) occur in vehicles under
2,722 kilograms (6,000 pounds) GVWR. These differences reflect the fact
that there are far fewer vehicles in this category in the on-road
fleet, and may also reflect the vehicles' size and weight as well as
their frequency of use as working vehicles. Heavier vehicles generally
are less likely to roll over than lighter vehicles.
We recognize the argument that all light vehicles should meet the
same SWR requirements, to ensure the same minimum level of protection
in a rollover crash. However, in selecting particular requirements for
a final rule, we believe that our focus must be on saving lives while
also considering costs and relative risk. What is necessary to meet the
need for safety and is practicable for one type or size of vehicle may
not be necessary or reasonable, practicable and appropriate for another
type or size of vehicle. Thus, to the extent the goal of establishing
the same SWR requirements for all light vehicles would have the effect
of either unnecessarily reducing the number of lives saved in lighter
vehicles or imposing substantially higher, unreasonable costs on
heavier vehicles despite their lesser relative risk, we believe it is
appropriate to adopt different requirements for different vehicles. We
also observe that because the same SWR requirement is significantly
more stringent for heavier vehicles than lighter vehicles (due to SWR
being a multiple of unloaded vehicle weight), establishing the same SWR
requirement for heavier vehicles is not simply a matter of expecting
manufacturers to provide the same countermeasures as they do for light
vehicles.
Vehicles with a GVWR of 2,722 kilograms (6,000 pounds) or less.
Our decision to adopt a 3.0 SWR requirement for vehicles with a
GVWR of 2,722 kilograms (6,000 pounds) or less, i.e., the vehicles
currently subject to the standard, reflects the higher life-saving
benefits associated with that requirement. It also reflects our
consideration of the test results of current vehicles. We believe the
high SWR levels that are currently being achieved for a range of light
vehicles demonstrate that manufacturers can achieve this SWR level for
these vehicles.
An SWR requirement of 3.0 prevents about 66 percent more fatalities
than one at 2.5, 133 instead of 80. However, costs increase by a
considerably higher percentage, resulting in a less favorable cost per
equivalent life saved, $5.7 million to $8.5 million for 3.0 SWR as
compared to $3.8 million to $7.2 million for 2.5 SWR.
In these particular circumstances, we believe that a 3.0 SWR
requirement is appropriate and the costs reasonable given the increased
benefits. While the cost per equivalent life saved is relatively high
compared to other NHTSA rulemakings, we conclude that the higher safety
benefits, the legislative mandate for an upgrade, the technical
feasibility of making roofs this strong, and the fact that these costs
are generally within the range of accepted values justify moving
NHTSA's roof crush standards to a 3.0 SWR for vehicles that have been
subject to the 1.5 SWR requirements.
We decline, however, to adopt an even higher SWR requirement. In
considering higher SWR requirements at this level, costs continue to
increase at a considerably higher rate than benefits. The FRIA
estimates that while a 3.5 SWR requirement for these vehicles would
result in higher benefits, preventing 175 instead of 133 fatalities,
total costs would increase to $1.6 billion to $2.3 billion (about $800
million to $1.1 billion above the total costs for the 3.0 SWR
requirement) and the overall cost per equivalent life saved for these
vehicles would increase to $8.8 to $12.3 million. A 3.5 SWR requirement
would thus result in an approximate doubling of the costs beyond those
of a 3.0 SWR requirement, and deliver about \1/3\ more benefits.
Vehicles with a GVWR greater than 2,722 kilograms (6,000 pounds)
and less than or equal to 4,536 kilograms (10,000 pounds).
Vehicles with a GVWR greater than 2,722 kilograms (6,000 pounds)
are not currently subject to FMVSS No. 216 and, because of their
greater unloaded vehicle weight, these vehicles pose greater design
challenges. Moreover,
[[Page 22361]]
given the relatively small target population for these vehicles, the
benefits will necessarily be small regardless of the SWR selected.
After considering our original proposal of a SWR of 2.5 and the
available information, we have concluded that a SWR of 1.5 is
appropriate for these heavier vehicles. The requirement we are adopting
is more stringent than the longstanding requirement that has applied to
lighter vehicles until this rulemaking because it is a two-sided
requirement. The FRIA estimates that two fatalities and 46 nonfatal
injuries will be prevented annually by this requirement. Because of the
high cost relative to the benefits for all of the alternatives for
these heavier vehicles, from the 1.5 SWR alternative and above, any
alternative we select would adversely affect the overall cost
effectiveness of this rulemaking (covering all light vehicles).
We believe that a SWR of 1.5 is appropriate for these heavier
vehicles. Given the requirements of SAFETEA-LU, we need to ensure that
the standard results in improved real world roof crush resistance for
these vehicles. We decline, however, to adopt a SWR higher than 1.5 for
vehicles with a GVWR greater than 2,722 kilograms (6,000 pounds), given
the small additional benefits (4 additional lives saved) and
substantially higher costs. Adopting a SWR of 2.0 for these vehicles
would more than double the costs of this rule for these vehicles to
prevent 4 additional fatalities and 137 nonfatal injuries.
Other issues related to strength requirements and SWR.
As indicated above, the Alliance cautioned against increasing the
SWR beyond 2.5 for lighter vehicles due to the potential adverse
effects of increased mass. It stated that recommendations in the docket
for higher levels did not attempt to account for the potential effect
on the SSF of adding structure necessary to comply with higher
standards.
We do not believe that it is necessary to account for that effect.
We note that the agency has considered a number of issues related to
added weight as part of the FRIA, including possible adverse effects to
safety. Based on our analysis, we believe that today's rule will not
result in adverse effects to safety as a result of added weight.
For a number of reasons, including ones related to CAFE standards,
fuel prices, and rollover propensity, we believe manufacturers will
strive to minimize the weight impacts of added roof strength. While
there is a great deal of uncertainty regarding the actual changes that
manufacturers will initiate in response to this rule, there are
numerous ways to address both roof strength and rollover propensity
simultaneously. This final rule provides substantial leadtime within
which to choose among those ways and make design changes that avoid
adversely affecting that propensity. There is evidence from current
NCAP ratings that manufacturers are routinely doing so. Manufacturers
generally strive to maintain or improve their NCAP ratings to help
market their vehicles. The agency believes that this concern over NCAP
ratings would preclude a design strategy that unnecessarily increases
CG and degrades SSF. Further, agency testing of 10 redesigned vehicles
with higher roof strengths found that manufacturers had maintained SSF
levels while increasing roof strength in newly redesigned models.
A detailed discussion of issues related to added weight and SSF is
included in the FRIA, and there is also additional discussion later in
this document.
Mercedes-Benz suggested that, for a two-sided test requirement, the
SWR on the second side should be lower than what would be required for
the first side. According to Mercedes, this would reflect the lower
force levels in a rollover that it said the second side would
experience. However, as discussed above in the section on single-sided
or two-sided tests, the agency's analysis of NASS data indicates that
vehicles experience more intrusion on the far side (second side) of the
vehicle than the near side. Therefore, we decline to adopt a lower SWR
requirement for the second side. We note that the agency took into
account the costs and benefits of a two-sided test requirement with the
SWR at the same level for both sides.
As to the issue raised by CSRL about safety standards that are
technology-forcing, that commenter did not provide specific information
concerning what it contemplated in this area. As part of the agency's
analysis of costs and benefits, we considered the use of advanced
higher strength and lighter weight materials. Our analysis assumes
significantly greater implementation and use of these advanced
materials.
Finally, we note that several commenters suggested that the agency
use alternative approaches other than unloaded vehicle weight for
purposes of calculating SWR. Recommendations included using weight of
the vehicle plus two occupants, or GVWR plus two occupants. We decline
to change FMVSS No. 216's existing approach of using a multiple of
unloaded vehicle weight for calculating the force requirement that
applies to each vehicle. Using a weight higher than unloaded vehicle
weight would simply represent another means of increasing stringency
and would be equivalent to a requirement for a higher SWR. However, the
agency has already considered alternative higher SWR levels, as well as
a two-sided test requirement, which also represent an increase in
stringency. Thus, the other issues we have considered ensure an
appropriate level of stringency.
5. Performance Criteria--Headroom, Platen Travel, or Both
In the NPRM, we proposed to replace the current limit on platen
travel (test plate movement) during the specified quasi-static test
with a requirement that the crush not exceed the available headroom. We
were concerned that the platen travel limit does not provide adequate
protection to front outboard occupants of vehicles with a small amount
of occupant headroom. We also stated that the current requirement may
impose a needless burden on vehicles with a large amount of occupant
headroom.
Under our proposal, no roof component or portion of the test device
could contact the head or neck of a seated Hybrid III 50th percentile
adult male dummy during the specified test. We believed that this
direct headroom reduction limit would ensure that motorists receive an
adequate level of roof crush protection regardless of the type of
vehicle in which they ride. We included a definition of the term ``roof
component'' as part of the proposal.
We noted a concern that there may be some low roofline vehicles in
which the 50th percentile Hybrid III dummy would have relatively little
available headroom when positioned properly in the seat. That is, we
were concerned that, in some limited circumstances, the headroom
between the head of a 50th percentile male dummy and the roof liner is
so small that even minimal deformation resulting from the application
of the required force would lead to test failure. We requested comments
on whether any additional or substitute requirements would be
appropriate for low roofline vehicles.
In the NPRM, the agency estimated benefits based on post-crash
headroom, the only basis for which a statistical relationship with
injury reduction had been established. In our January 2008 SNPRM, we
explained that with additional years of available data, a statistically
significant relationship between intrusion and injury for belted
occupants had been established. A
[[Page 22362]]
study regarding this relationship was placed in the docket.\19\
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\19\ Strashny, Alexander, ``The Role of Vertical Roof Intrusion
and Post-Crash Headroom in Predicting Roof Contact Injuries to the
Head, Neck, or Face during FMVSS 216 Rollovers.''
---------------------------------------------------------------------------
We also noted in the January 2008 SNPRM that in the most recent
agency testing, headroom reduction had been assessed using a head
positioning fixture (HPF) in lieu of a 50th percentile adult male
dummy. We stated that reports on these tests explain the procedure and
type of fixture used to assess headroom reduction, and that the test
reports were being made available to the public. We noted further that
the agency was considering whether this fixture should be specified in
the final rule.
Comments
The agency received a variety of comments on the proposed headroom
reduction criterion.
One group of commenters, including safety advocacy organizations,
generally supported adding a headroom reduction criterion but, in some
cases, argued that a platen travel criterion is also needed. Some of
these commenters also argued that these criteria should be made more
stringent to protect taller occupants.
Another group of commenters, including vehicle manufacturers, urged
the agency to retain the current platen travel criterion instead of
adopting a headroom reduction criterion. They argued, among other
things, that using the headroom reduction criterion would add
unnecessary complexity to the test procedure and result in problems
related to repeatability and practicability.
Specific issues raised by commenters include:
Repeatability and practicability issues. Several commenters,
including the Alliance, DaimlerChrysler, GM, Ford, and Porsche, cited
concerns related to reliability and practicability of using a test
dummy for purposes of the FMVSS No. 216 quasi-static test.
DaimlerChrysler, Ford and GM stated that variations in test dummy
placement cause variability in the distance between the dummy head and
the roof side rails. In test results cited by GM, horizontal and
vertical variations of an inch or more occurred in the dummy's seating
position. GM stated that this variability is further complicated when
vehicles with different trim and seating options (cloth or leather,
manual or power adjusters) are provided using the same vehicle
architecture structure. It suggested that such options add to the
variability and make the proposed requirement of measuring roof crush
resistance with a seated Hybrid III dummy non-repeatable and
impracticable.
Porsche also expressed concern with controlling unwanted movement
of the dummy with its roof crush test set-up. The Porsche roof crush
test procedure rotates the vehicle by 90 degrees because their platen
press applies a load parallel to the ground. The dummy is not fixed
into position and, as a result, would rotate and not be properly
positioned.
Complexity. IIHS stated that relating the allowable amount of roof
crush in the quasi-static test to the headroom in specific vehicles is
a good concept but that, in practice, the agency's research tests have
not shown that replacing the 127 mm (5 inch) platen travel criterion
with the headroom requirement would be a meaningful change to the
standard and may not justify the added complications to the test
procedure.
Possible conflicts with FMVSS No. 201 ``Occupant protection in
interior impact.'' A number of commenters, including DaimlerChrysler,
Ford, GM, Ferrari and Toyota commented that the proposed headroom
requirement conflicts with the intent of the upper interior
requirements of FMVSS No. 201, Occupant Protection in Interior Impact.
DaimlerChrysler and GM stated that FMVSS No. 201U \20\ countermeasures
have been specifically developed to manage head impact energy and
mitigate injury potential by the dissipation of the impact energy
through deformation of the trim and FMVSS No. 201U countermeasures
themselves. Ford stated that head impact mitigation technologies often
result in the upper interior trim, particularly the roof side rail
trim, being closer to the head of occupants, thereby reducing the
available distance for achieving the SWR requirement prior to headform
contact. It stated that these technologies are designed to reduce the
likelihood of head impact injuries, and that the proposed no-contact
requirement does not account for the potential benefits of these
technologies in a roof deformation situation. GM further stated that
NHTSA's headroom analysis does not establish a correlation between
injuries and head contact with trim components.
---------------------------------------------------------------------------
\20\ FMVSS 201U, refers to those aspects of FMVSS No. 201
pertaining to the upper interior trim head protection requirements.
---------------------------------------------------------------------------
Effects on vehicle manufacturing process GM stated that since the
vehicle roof structure is designed very early in the vehicle
development process, it is not possible to reliably predict the
performance or movement of interior trim in a roof crush test. It
stated that structural designs must be completed early in the vehicle
development process to facilitate tooling lead time. According to GM,
the interior trim components (included in the proposed definition of
roof component) are not designed in final form until much later in the
vehicle development process. Therefore, according to that commenter,
the roof structure force deflection characteristics are defined (and
roof crush properties established) before manufacturers can take into
account the package space and deformation requirements of the interior
trim.
Reduced stringency of the standard Several commenters, including
Public Citizen, IIHS, and LSMM expressed concern that the proposed head
contact criteria could reduce the residual occupant headroom required
after testing, be less stringent for vehicles with existing headroom
greater than 127 mm (5 inches), and thereby allow more than 127 mm (5
inches) of crush. As a result, according to these commenters, the
stringency would be reduced for vehicles with greater than 127 mm (5
inches) of headroom, such as many trucks and Sport Utility Vehicles
(SUVs). We note that Ford commented that most of its light trucks,
multipurpose passenger vehicles and vans (LTVs) have more than 127 mm
(5 inches) of platen travel prior to head contact, while passenger cars
generally have less.
Alternative headroom requirement approaches A number of commenters
recommended alternative approaches to the proposed headroom
requirement. Biomech Incorporated (Biomech) suggested using a one
gravity static inversion test (using the FMVSS No. 301 fixture) to
learn where the inverted dummy head position would be. It suggested
that deformation in the roof crush test should not be permitted to
reach the measured position of the inverted dummy's head.
GM, DaimlerChrysler, Toyota, Ferrari and Porsche recommended that
if the agency establishes a headroom reduction criterion, it consider
using a headform position procedure (HPF) that essentially represents a
headform secured to an adjustable vertical support that is rigidly
attached to the floor pan of the tested vehicle at the seat anchorages.
A number of these commenters also suggested that the agency
consider removing any roof trim components (i.e., all headliner, trim,
deployable countermeasures and grab handles) prior to testing. Further,
these commenters also recommended that
[[Page 22363]]
head contact with the roof structure itself be the only assessment
criteria for compliance certification. GM recommended that
manufacturers provide the headform location to NHTSA prior to a
compliance test based upon the nominal design seating positions.
Toyota, by contrast, recommended the agency determine the location for
the 50th percentile male head position with the Head Restraint
Measuring Device (HRMD) \21\ after first determining the H-point using
the SAE J826 procedure, and then position the headform in the vehicle.
---------------------------------------------------------------------------
\21\ HRMD means the SAE J826 three-dimensional manikin with a
headform attached, representing the head position of a seated 50th
percentile male, with sliding scale at the back of the head for the
purpose of measuring head restraint backset.
---------------------------------------------------------------------------
DaimlerChrysler recommended verifying compliance by a 200 N (44
pounds) resultant contact force in the upper neck load cell of a 50th
percentile adult male Hybrid III head fixture at the location specified
in the NPRM. DaimlerChrysler recommended that in the event the platen
does not stop quickly enough after the resultant neck force reaches 200
N (44 pounds); the head fixture should be designed to either withdraw
or become compliant by using a force limiting device in order to
prevent any damage to the load cell in the dummy's head. GM also
recommended a similar approach and suggested the agency consider a
range of loads on the headform of 100 N (22 pounds) to 400 N (88
pounds).
Advocates recommended a maximum intrusion limit of no more than
76.2 mm (3 inches) in order to protect occupants taller than the 50th
percentile male. Public Citizen recommended that NHTSA require that
vehicle roof structures resist more than 76.2 mm (3 inches) of roof
crush, and maintain the minimum amount of headroom proposed in the NPRM
in order to reduce side window breakage and prevent B-pillar
deformation, which it believes can alter seat belt geometry.
ARCCA, Mr. Slavik and the Advocates also recommended the agency use
a 95th percentile adult male dummy instead of the smaller 50th
percentile male to increase the stringency of the standard and further
limit intrusion.
Testing with HPF: As noted above, the agency indicated in the SNPRM
that it was considering whether to specify a test using a HPF in the
final rule. We received a number of comments concerning this issue.
The Alliance reiterated its recommendation that NHTSA maintain the
use of the 127 mm (5 inch) platen travel criterion. That organization
stated that it does not support a ``no head contact'' criterion,
whether it is determined by use of a test dummy or via the use of an
HPF with an associated contact force. The Alliance stated that the
platen travel requirement would yield essentially the same roof
strength and avoid unnecessary test-to-test variability and testing
complexity. That organization stated that if the agency adopts a head
contact criterion in the final rule, it is essential that the head
contact device be a headform on a stand located at a position specified
by the manufacturer and not a crash test dummy or a headform located
based on what it claimed would be very unreliable and unrepeatable
location data estimated from a test dummy or SAE J826 manikin (OSCAR)
location. The Alliance stated that possible use of a 222 N (50 pound)
contact criterion has not been supported by any scientific data.
In commenting on the SNPRM, GM stated that use of the 127 mm (5
inch) platen travel criterion rather than either a dummy or head
contact fixture is required to prevent unnecessary test variation and
complication while maintaining a comparable level of stringency.
AIAM did not endorse the HPF approach but suggested that the
fixture might be equipped to measure neck load, to exclude incidental
contact with trim items.
Public Citizen stated that defining head contact with the HPF by
using force-deflection criteria would result in a significant number of
front seat occupants suffering head and neck injuries.
Agency Response
After carefully considering the comments, the agency has decided to
adopt the proposed headroom requirement, but with a different test
procedure. Instead of specifying a procedure using a seated Hybrid III
adult male dummy, we are specifying use of a HPF that positions the
headform at the location of a 50th percentile adult male. To help
ensure objectivity and in light of concerns about incidental contact
with trim, head contact is defined as occurring when a 222 N (50 pound)
resultant load is measured by a load cell on the HPF. Finally, to
better ensure safety, we are retaining the current 127 mm (5 inch)
platen travel requirement as well as adopting a headroom requirement.
Primary Rationale: At the time of the NPRM, the agency estimated
benefits based on post-crash headroom, the only basis for which a
statistical relationship with injury reduction had been established.
After the NPRM, with additional years of data available, a
statistically significant relationship between intrusion and injury for
belted occupants was established.
NHTSA cited its new headroom and roof intrusion analysis \22\ in
the SNPRM. The agency added two years of NASS-CDS data to each analysis
and found a new, stronger negative correlation between post-crash
headroom and maximum injury severity of head, neck or face from roof
contact. Also, for the first time, the agency was able to find a
statistically significant correlation between vertical roof intrusion
and head, neck, or face injury from roof contact. Based upon this new
analysis, we believe that maintaining headroom, as well as restricting
the amount of intrusion (retaining the platen travel requirement) will
yield benefits in rollover crashes. Therefore, we believe both criteria
should be included in the final rule.
---------------------------------------------------------------------------
\22\ ibid
---------------------------------------------------------------------------
Commenters opposing adoption of a headroom requirement raised a
number of concerns, including ones related to the test procedure,
practicability concerns, and whether a headroom requirement would
result in benefits beyond those of the platen travel requirement. The
issues related to the test procedure and practicability concerns are
addressed below.
As to the issue of additional benefits associated with the headroom
criterion, we note that, based on our testing, in the vast majority of
vehicles it is likely that the limit on platen travel will be
encountered before the one on headroom reduction. For these vehicles,
the new requirement will not pose any significant challenges for
manufacturers, particularly in light of the changes we are making in
the test procedure. However, as we also consider vehicles with less
headroom and potential future vehicles, we believe there is a need to
adopt a headroom reduction requirement to help ensure post-crash
survival space.
In the NPRM, we raised a concern that for vehicles with greater
than 127 mm (5 inches) of headroom, limiting platen travel to 127 mm (5
inches) may impose a needless burden on these vehicles. However,
manufacturers generally supported retaining the platen travel limit,
suggesting that the requirement is not burdensome. Moreover, as
indicated above, we now have a new analysis showing a statistically
significant relationship between intrusion and injury for belted
occupants.
Basic Test Procedure for Measuring Head Contact: To help analyze
comments raising repeatability concerns
[[Page 22364]]
with the Hybrid III dummy and identifying when head contact occurred,
the agency conducted a series of tests using alternative approaches. In
the first series of tests conducted at NHTSA's Vehicle Research and
Test Center (VRTC), the agency used a head positioning fixture
developed by GM (GM-HPF).\23\ The GM-HPF is a headform secured to an
adjustable vertical support that is rigidly attached to the floor pan
at the seat anchorages. The GM-HPF rigidly holds a headform in the
location of a normally-seated 50th percentile male head and measures
the load on the headform from contact with the interior roof as it is
crushed.
---------------------------------------------------------------------------
\23\ See Docket Number NHTSA-2005-22143-195
---------------------------------------------------------------------------
The headform consists of a skull, headskin, and 6-axis upper neck
load cell from a 50th percentile male Hybrid-III dummy (Part 572,
subpart E). This assembly is mounted to the end of a channeled square
tube (upper post). A second, similar tube (lower post) is
perpendicularly mounted to a rectangular aluminum mounting plate. The
upper and lower posts attach to each other and are parallel. The upper
post can slide along the lower post. This provides vertical adjustment
of the headform once the fixture is mounted in the vehicle. The GM-HPF
also includes four metal support straps that attach between the upper/
lower post and the mounting plate, in a pyramid configuration. These
straps provide rigidity to the fixture and are attached after final
positioning of the headform.
In the testing conducted at VRTC,\24\ the head position of a
normally seated 50th percentile male Hybrid-III dummy was determined by
placing the seat at the mid-track position and using the SAE J826
(OSCAR) device to locate the H-point. A 50th percentile male Hybrid-III
dummy was then positioned per the FMVSS No. 208 seating procedure and
the head location was documented using a 3-dimensional measurement
device. The dummy and seat were then removed. The GM-HPF mounting plate
was attached to the vehicle floor and the headform was then raised
until its vertical position matched that determined from dummy
placement.
---------------------------------------------------------------------------
\24\ See docket entry NHTSA 2008-0015-003 for the vehicles
tested with the GM-HPF.
---------------------------------------------------------------------------
After gaining experience with the GM-HPF, the agency developed its
own, simpler HPF approach for evaluating post crash headroom. In doing
so, the agency determined that it is not necessary to use a test device
with the complexity of a headform based on the Hybrid III dummy head,
given the nature of the performance criterion being measured. Earlier
testing had shown that the skin on the Hybrid III dummy's head added a
level of testing complexity that was unnecessary to the goal of
identifying when roof contact occurs at a point in space. Therefore,
the agency developed a simpler HPF using an FMVSS No. 201 headform that
is currently used for testing instrument panels and seat backs. (This
headform is effectively a 16.5 cm (6.5 inch) diameter metallic
hemisphere).
During roof crush test series conducted at General Testing
Laboratories,\25\ the HPF was developed by mounting the FMVSS No. 201
headform to a cantilevered levering arm which was then attached to a
tri-pod. The levering arm was maintained in position by air pressure
and designed to collapse after a 222 N (50 pound) load was applied. The
purpose of the cantilever design was to allow some downward movement so
as not to damage the device after head contact is reached. The HPF was
positioned in the vehicle at the 50th percentile male head position
using the FMVSS No. 214 seating procedure recently adopted (72 FR
51908) and modified to use the OSCAR with a Head Restraint Measuring
Device attached for repeatable placement. The HPF tri-pod apparatus was
then rigidly secured to the floor of the vehicle. The FMVSS No. 201
headform was mounted on a 3-axis dummy neck load cell, and all loads
and moments were recorded. The roof was then crushed until the
unmodified interior roof made contact with the HPF and the resultant
load, as measured by the load cell, exceeded 222 N (50 pounds). During
our evaluation we defined ``head contact'' as occurring when a 222 N
(50 pound) load is applied to the sphere, in the belief that this load
level would correspond to structural roof contact rather than interior
trim components coming loose. This was consistent with comments from
DaimlerChrysler and GM that used a force load approach as a reliable
method of identifying head contact and removing the uncertainty of
random interior trim contact.
---------------------------------------------------------------------------
\25\ See report Two-Sided Roof Crush Testing Analysis placed in
the docket with this notice.
---------------------------------------------------------------------------
Our test experience with the simpler HPF proved to be repeatable in
the tests and easier than using the Hybrid III dummy itself during the
test.
We believe specification of the HPF appropriately addresses
commenters' concerns regarding variability with regard to locating the
dummy's head. With the HPF rigidly fixed to the vehicle, we also
believe this addresses the concerns of manufacturers, such as Porsche,
which alter the attitude of the vehicle with respect to the load press
when conducting roof crush tests.
Because head contact is defined as a load on the headform, the test
result is more objective/repeatable, and not sensitive to incidental
contact with interior surfaces that may disengage during testing.
We disagree with comments from manufacturers that recommended the
removal of the roof's interior trim prior to testing in order to
simplify the procedure. The agency's headroom analysis established a
correlation between injuries and head contact with a NASS-CDS roof
component when the injury source was the A-Pillar, B-Pillar, front or
rear header, roof rail or the roof itself. These interior surfaces are
considered interior trim. We believe they should be factored in when
considering the available headroom in the test. By defining head
contact as occurring when a 222 N (50 pound) load is applied to the
headform, we are addressing concerns about incidental contact with
trim. This definition of head contact also addresses concerns about
possible conflicts with the intent of FMVSS No. 201U, with respect to
concerns with incidental contact. If the headform experiences a 222 N
(50 pound) load, the contact is not incidental and there is a safety
issue related to available headroom.
We also disagree with comments from manufacturers recommending that
the head contact device be a headform on a stand located at a position
specified by the manufacturer and not a crash test dummy or a headform
located based on SAE J826 manikin (OSCAR) location. The HPF test
procedure (as would a test procedure using a test dummy) measures head
contact in the vehicle being tested. However, the approach of using a
headform on a stand located at a position specified by the manufacturer
would not necessarily represent the actual vehicle build.
We note that the SAE J826 mannequin has long been incorporated in
NHTSA's safety standards for purposes of determining the H-point
location. Issues concerning the accuracy of measurements using this
device and the HRMD were addressed at length in our rulemaking
upgrading our head restraints standard. Manufacturers can address
concerns about different trim and seating options by factoring in the
location where the headform (and also the head of a typical average
size male occupant) will be under those different options.
Definition of head contact:
As noted above, the Alliance stated that possible use of a 222 N
(50 pound) contact criterion has not been supported
[[Page 22365]]
by any scientific data. Public Citizen expressed concern that defining
head contact with the HPF by means of force-deflection criteria would
result in a significant number of front seat occupants suffering head
and neck injuries.
We note that the load as defined is not intended to be an injury
criterion, for which one would expect supporting scientific data, but
is instead simply an objective way of defining head contact and
avoiding treating incidental contact with loose trim as head contact.
Our testing has shown, on average, once physical contact between the
interior roof trim and the headform occurred resulting in the onset of
a load on the headform, the platen traveled 6 mm (0.24 inches) prior to
the load reaching 220 N (50 pounds). Therefore, we do not expect
increased head and neck injuries from this approach. Moreover,
retention of the current platen travel requirement will also prevent
such increased injuries. We selected the 222 N (50 pound) contact
criterion based on comments from GM and DaimlerChrysler and our own
testing experience.
Possible Reduced Stringency:
IIHS, LSMM and Public Citizen expressed concern that if the platen
travel requirement were not retained in addition to adopting the
headroom criterion, adoption of the proposed headroom criterion would
represent a decrease in stringency for the standard's performance
criterion. This is not an issue since we are retaining the platen
travel requirement.
Possible more restrictive requirements. We disagree with commenters
which recommended that the agency reduce the platen travel requirement
to 76.3 mm (3 inches).
On average, the vehicles the agency has tested have reached the
maximum SWR in 90 mm (3.5 inches) of platen travel. A requirement for
reduced platen travel would represent an increase in stringency and, in
many respects, would be similar to a requirement for a higher SWR. We
note that the agency has already been considering the possibility of a
higher SWR, as well as two-sided test requirement, which would also
increase stringency. We have not conducted testing to analyze the
appropriateness of applying a 3 inch platen travel requirement to all
vehicles. However, we believe the other issues we have considered
ensure an appropriate level of stringency.
We also do not agree with commenters recommending the use of the
95th percentile dummy (or equivalent HPF) for measuring head contact.
Restricting headroom to a 95th percentile occupant is similar to
limiting the platen displacement to 76.3 mm (3 inches) in increasing
stringency. As indicated above, we believe the other issues we have
considered ensure an appropriate level of stringency. Moreover, we
believe that the relationship between vehicle headroom and occupant
size is insignificant in most cases. It is likely that taller front
seat occupants adjust the seat positions to prevent uncomfortable
proximity to the roof such as by lowering the seat cushion bottom,
increasing the seat back angle and/or adjusting the seat position
further rearward.
Low roofline vehicles: In the NPRM, we discussed possible concerns
with vehicles that have relatively little available headroom when the
50th percentile adult male dummy is positioned properly in the seat.
Vehicles with these aerodynamically sloped roofs will hereafter be
referred as ``low roofline vehicles.'' We stated that we were concerned
that, in some limited circumstances, the headroom between the head of a
50th percentile male dummy and the interior headliner is so small that
even minimal deformation resulting from the application of the required
force would lead to test failure. NHTSA requested comments on whether
any additional or substitute requirements would be appropriate for low
roofline vehicles in order to make the standard practicable.
Several commenters, including DaimlerChrysler, Ford, Porsche,
Mitsubishi Motors R&D of America, Inc. (Mitsubishi) and Hyundai America
Technical Center, Inc. (Hyundai), provided comments on low roofline
vehicles. The commenters recommended that the requirements be limited
to 127 mm (5 inches) of deflection for a load of 2.5 SWR in order to
minimize the negative impact on continued availability of this type of
vehicle if the agency were to adopt a headroom requirement.
DaimlerChrysler stated that the proposed standard was not reasonable,
practicable and appropriate for these types of motor vehicles as
required by the Motor Vehicle Safety Act. It further stated that the
agency had not demonstrated in the NPRM or the PRIA, the feasibility of
going beyond 1.5 times the UVW in roof strength without head contact
for vehicles with steeply raked windshields and reduced headroom.
DaimlerChrysler suggested its recommendation would be applicable to
the Chrysler Crossfire, Dodge Viper, and McLaren Mercedes models and
successors, which are generally designed with a steeply raked
windshield and a low roofline for reduced frontal area and low drag. It
further stated that this modified requirement should also apply to
other kinds of vehicles, such as any two-seater that is designed with a
more aggressively raked windshield. DaimlerChrysler recommended that
vehicles of this type could be identified or defined based on a set of
characteristics such as the Static Stability Factor (SSF) (e.g.,
>=1.4), NCAP rollover rating (e.g., >=4 stars), height-to-width ratio
(e.g., <=0.75), windshield rake angle, vehicle height, etc.
Ford stated that low roofline vehicles are not the only vehicles
that have problems with limited headform clearance. It stated that
vehicles that may be considered as ``high roofline'' can also have
limited headform-to-roof clearance due to interior package design.
Based on the interior package design of a particular vehicle,
regardless of roof line characteristics, the critical dimension
(distance between the outboard side of dummy's headform and the roof
side rail trim) can be minimal. Mitsubishi commented that headform-to-
roof clearance is a concern for not only low roofline vehicles but may
be more generically classified as being an issue for limited headroom
vehicles.
Porsche expressed concern that low roofline vehicles have less
opportunity for enhanced roof structures because the focus on
performance and aerodynamics virtually eliminates the option of taller
pillar supports.
Hyundai stated it will be challenging for low roofline vehicles and
particularly two door coupe vehicles to meet the upgraded standard
because of the lack of headroom and the possibility the B-pillar may
not be loaded because it is further away from the A-pillar compared to
a sedan. It requested that the agency define a low roofline vehicle to
explicitly include two-door coupe vehicles in the definition. It also
requested that these types of vehicles be allowed to meet the current
requirements until it can be demonstrated that practicability with the
upgrade is feasible.
Based on its analysis, the agency believes the requirements it is
adopting will not create new problems for low roofline vehicles. In our
most recent two-sided research program, the agency tested a 2006
Chrysler Crossfire, a vehicle identified as a low roofline vehicle.
During the first-side test, the vehicle had a peak SWR of 2.9 at 97 mm
(3.85 inches) of platen displacement. Head contact based upon our
criteria (222 N load on the headform) occurred at 107 mm (4.21 inches)
of platen travel. This showed the maximum SWR was reached prior to head
contact. On the
[[Page 22366]]
second side, the Crossfire reached a 2.7 SWR prior to head contact at
135 mm (5.31 inches) of platen travel.
The agency tested another low roofline vehicle, the 2007 Scion tC.
This vehicle achieved a maximum SWR of 4.6 on the first side at 113.3
mm (4.46 inches) of platen travel. Head contact occurred at 119 mm
(4.68 inches) of platen travel. On the second side, the Scion achieved
a 4.1 SWR prior to head contact at 95.0 mm (3.74 inches) of platen
travel. From these tests we believe it is feasible and practicable for
smaller vehicles with less initial headroom to meet the requirements.
Since both are two-door vehicles, we disagree with Hyundai's assertion
that two-door vehicles pose an unreasonable challenge.
We agree with Ford's observations that some vehicles that may
appear to be ``high roofline'' vehicles, but may experience head
contact in less platen travel than a ``low roofline'' vehicle. The 2007
Buick Lucerne, a large full size vehicle reached a maximum SWR of 2.3
at a platen displacement of 110 mm (4.33 inches). The vehicle did not
reach the proposed SWR of 2.5. In this test, platen travel at head
contact was less than the Crossfire. Therefore, the arguments being
made for excluding low roofline vehicles may not be unique to low
roofline vehicles. Ford's comments also illustrate the difficulty in
identifying what is or is not a low roofline vehicle.
DaimlerChrysler suggested SSF or other vehicle parameters could be
used to define low roofline vehicles and exclude them from the headroom
requirement. However, we believe that this exclusion is not warranted
based on our testing. Moreover, we are concerned about the safety
impact of unnecessarily excluding vehicles from the upgraded
requirements.
6. Leadtime and Phase-In
NHTSA proposed that manufacturers be required to comply with the
new requirements three years after the issuance of the final rule. At
that time, based upon vehicle testing, we estimated that 68 percent of
the current fleet already complied with the proposed roof strength
criteria. We anticipated the proposal would not require fleet-wide roof
structural changes and believed the manufacturers had engineering and
manufacturing resources to meet the new requirements within that
timeframe.
In commenting on the NPRM, vehicle manufacturers and their
associations argued that additional leadtime was needed, and that a
significantly greater portion of the fleet would require redesign than
estimated by the agency. The Alliance, Ford and GM stated that
approximately 60 percent of their fleets would need to be redesigned,
and Hyundai commented that 75 percent of its vehicles would need
changes to comply with the requirements.
Toyota, Ford, GM, Hyundai, Nissan and DaimlerChrysler stated that
the agency underestimated the necessary modifications to vehicle design
and manufacturing challenges that must be overcome to comply with the
proposal. Ford, GM, DaimlerChrysler, and Toyota stated that the
challenges are especially true for heavier vehicle over 2,722 kg (6,000
pounds) GVWR which have not been required to meet FMVSS No. 216.
GM and Ford stated that they rely on outside suppliers for advanced
high strength material and currently there is an insufficient supply
base for high strength steel. They also cited significant manufacturing
challenges that must be overcome to adapt ultra high strength steel to
the mass production environment. They argued that leadtime with a
phase-in is necessary to permit growth in the supply base and allow the
manufacturers to resolve manufacturability issues for high volume
production requirements.
The vehicle manufacturers generally requested a 3-year leadtime
followed by a multi-year phase-in. Most supported a minimum 3-year
phase-in. GM requested a 4-year phase-in period, and DaimlerChrysler
requested a 5-year phase-in only for vehicles over 3,855 kg (8,500
pounds). The AIAM requested compliance credits for an early phase in,
while the Alliance, Ford and Mitsubishi requested carryforward credits.
The AIAM and Ferrari requested that small volume manufacturers be
permitted to comply at the end of the phase-in due to compliance
difficulties, long product cycles and cost penalties associated with
running structural changes to vehicle programs.
In commenting on the SNPRM, the Alliance reiterated points made in
its comment on the NPRM, stating that the final rule needs to provide
at least three years initial leadtime followed by a multi-year phase-in
with carryforward credits. It stated that additional time is needed if
the agency adopted the proposed head contact criterion, a two-side test
requirement, or an SWR higher than 2.5. Ford suggested that if the
agency adopted a more stringent requirement than the one it focused on
in the NPRM, that vehicles meeting a 2.5 SWR/one-sided test requirement
earn compliance credits before and during the phase-in.
Agency Decision/Response
After carefully considering the comments and available information,
and for the reasons discussed below, we have decided to adopt different
implementation schedules for vehicles with a GVWR of 2,722 kilograms
(6,000 pounds) or less, i.e., the vehicles currently covered by FMVSS
No. 216, and those with a higher GVWR. The implementation schedules we
are adopting are as follows:
Passenger cars, multipurpose passenger vehicles, trucks and buses
with a GVWR of 2,722 kilograms (6,000 pounds) or less. We are adopting
a phase-in of the upgraded roof crush resistance requirements for these
vehicles. The phase-in requirement for manufacturers of these vehicles
(with certain exceptions) is as follows:
--25 percent of the vehicles manufactured during the period from
September 1, 2012 to August 31, 2013;
--50 percent of the vehicles manufactured during the period from
September 1, 2013 to August 31, 2014;
--75 percent of the vehicles manufactured during the period from
September 1, 2014 to August 31, 2015;
--100 percent of light vehicles manufactured on or after September 1,
2015.
Credits may be earned during the phase-in, i.e., beginning
September 1, 2012, and carried forward through August 31, 2015.
Small volume manufacturers are not subject to the phase-in but must
meet the requirements beginning on September 1, 2015. Vehicles produced
in more than one stage and altered vehicles must meet the upgraded
requirements beginning September 1, 2016.
Multipurpose passenger vehicles, trucks and buses with a GVWR
greater than 2,722 kilograms (6,000 pounds) and less than or equal to
4,536 kilograms (10,000 pounds). All of these vehicles must meet the
requirements beginning September 1, 2016,\26\ with the following
exceptions. Vehicles produced in more than one stage and altered
vehicles must meet the requirements beginning September 1, 2017.
---------------------------------------------------------------------------
\26\ If heavier vehicles are designed to meet the new
requirements early, their production volumes are not to be included
when calculating the light vehicle fleet phase-in percent
compliance. The phase-in schedule for the two fleets are separate.
---------------------------------------------------------------------------
Our rationale for this implementation schedule is as follows.
As discussed in the FRIA, a significantly larger proportion of the
vehicle fleet will require changes than estimated at the time of the
NPRM. This
[[Page 22367]]
would be true even for a 2.5 SWR/one-sided test requirement, and the
proportion is higher for the 3.0 SWR/two-sided requirement. We
therefore agree that a combination of approximately three years
leadtime plus a multi-year phase-in is appropriate.
In developing the implementation schedule, we have considered costs
and benefits. The vast majority of the benefits of the rule come from
vehicles with a GVWR of 2,722 kilograms (6,000 pounds) and less. Of the
135 fatalities that will be prevented each year, 133 will come from
these lighter vehicles. Moreover, the lighter vehicles are generally
redesigned more often than the heavier vehicles. Also, manufacturers
are familiar with designing and testing the lighter vehicles to meet
the current FMVSS No. 216 requirements.
In order to implement the upgraded requirements in a cost effective
manner, we believe it is appropriate to provide approximately three
years of leadtime coupled with a 25 percent/50 percent/75 percent/100
percent phase-in for the lighter vehicles, and longer leadtime for the
heavier vehicles. The benefits for the heavier vehicles are relatively
small, and approximately seven years leadtime will generally permit
manufacturers to improve roof strength at the same time they redesign
these vehicles for other purposes.
While vehicle manufacturers made varying recommendations for the
specific provisions of a phase-in, the phase-in we are adopting for
lighter vehicles is within the general range of those recommendations.
We recognize that manufacturers argued that longer leadtime should be
provided for requirements more stringent than a 2.5 SWR/one-sided test
requirement. However, while the 3.0 SWR/two-sided test requirement will
increase the number of vehicles requiring redesign and the specific
countermeasures that are needed, we believe that approximately three
years of leadtime coupled with a 25 percent/50 percent/75 percent/100
percent phase-in provides sufficient time for manufacturers to make
these changes. We note that the vehicles likely to present the greatest
design challenges under our proposal were the ones with a GVWR above
2,722 kilograms (6,000 pounds), for which we are providing longer
leadtime and a lower SWR requirement. Vehicle manufacturers have not
provided persuasive evidence that longer leadtime is needed, or that a
less stringent requirement should be established for an initial period.
We believe that providing for carry forward credits during the
phase-in, but not the earning of advance credits prior to the beginning
of the phase-in, balances encouraging early compliance and manufacturer
flexibility with also encouraging manufacturers to continue to improve
roof strength during the years of the phase-in.
As with a number of other rulemakings, we are establishing special
requirements for small volume manufacturers and for vehicles produced
in more than one stage and altered vehicles.
Given the leadtime needed for manufacturers to redesign their
vehicles to meet the upgraded roof crush requirements, we find good
cause for the compliance dates included in this document.
b. Aspects of the Test Procedure
1. Tie-down Procedure
In the NPRM, we proposed to revise the vehicle tie-down procedure
in order to improve test repeatability. Specifically, we proposed to
specify that the vehicle be secured with four vertical supports welded
or fixed to both the vehicle and the test fixture. If the vehicle
support locations are not metallic, a suitable epoxy or an adhesive
could be used in place of welding. Under the proposal, the vertical
supports would be located at the manufacturers' designated jack points.
If the jack points were not sufficiently defined, the vertical supports
would be located between the front and rear axles on the vehicle body
or frame such that the distance between the fore and aft locations was
maximized. If the jack points were located on the axles or suspension
members, the vertical stands would be located between the front and
rear axles on the vehicle body or frame such that the distance between
the fore and aft locations was maximized. All non-rigid body mounts
would be made rigid to prevent motion of the vehicle body relative to
the vehicle frame.
We explained that we believed this method of securing the vehicle
would increase test repeatability. Welding the support stands to the
vehicle would reduce testing complexity and variability of results
associated with the use of chains and jackstands. We also stated that
we believed that using the jacking point for vertical support
attachment is appropriate because the jacking points are designed to
accommodate attachments and withstand certain loads without damaging
the vehicle.
Comments
Commenters on the proposed tie-down procedure included the
Alliance, DaimlerChrysler, Ford, GM, Toyota, AIAM, Mr. Chu, Hyundai and
BMW Group (BMW). A number of commenters agreed with the agency's
intention to revise the tie-down procedure for the quasi-static test to
improve test repeatability. However, manufacturers raised specific
concerns about the proposed procedure. AIAM, Mr. Chu, Hyundai and BMW
alternatively recommended retention of the current tie-down procedure.
Advocates and SAFE supported the revised tie-down procedure because it
has the potential to ensure less vehicle movement during testing.
Ford suggested that the proposed tie-down procedure can cause
localized, unrealistic floor pan deformations that can reduce the
measured strength of the roof. The Alliance, DaimlerChrysler, Ford, GM
and Toyota recommended providing one vehicle support per vehicle
pillar. However, they recommended placing the support along the sill,
as opposed to the jack points, since they stated that jack points are
not designed to withstand the forces generated during a roof crush
test. The commenters suggested that this would minimize unwanted body
displacement by providing a direct load path during testing which the
proposal does not address. For body-on-frame vehicles, DaimlerChrysler
also recommended support of the vehicle frame, in addition to the
pillar supports, to further prevent sag of the body. In the event that
the agency adopts the practice of supporting the body at the pillars,
the Alliance, GM, and BMW also requested that a minimum area of support
be provided to avoid concentrated loading.
The Alliance, BMW and Ford also had concerns about welding supports
to the vehicle body. The commenters stated that welding could decrease
the material properties of the body reducing the measured roof
strength, and welding might not be practical or possible for non-
ferrous or composite materials. BMW alternatively recommended clamping
instead of welding, citing concerns about welding certain materials and
the possibility of failure of the sills due to the welding. Ford
recommended contacting the manufacturer for instructions about welding
aluminum sills, if the agency proceeded with the welding protocol.
AIAM, Mr. Chu, Hyundai and Nissan recommended maintaining the
existing procedure that supports the entire length of the sill in order
to reduce complexities and unwanted body deformation with the tie-down
proposal. Nissan suggested supporting the wheelbase at the sill flange
pinch welds between the two channels that grab the
[[Page 22368]]
pinch weld on the bottom of the sill. The side sill flange would be
constrained to prevent transverse body movement when tested. Hyundai
recommended that the current procedure be permitted at the
manufacturer's option since it believes the revised tie down procedure
is burdensome. DaimlerChrysler and Toyota also recommended continuous
mounting along the sills suggesting this would prevent unwanted body
deformation at the jack point locations.
For vehicles without B-pillars, the Alliance, Ford, and GM
recommended that a support be placed at the seam between the doors as
if a pillar existed between the doors. The Alliance stated that doors
connected without a pillar often have reinforcements to compensate for
the structure that would be afforded by a pillar if it were part of the
vehicle design, and therefore, the joint between the doors will act as
one of the direct load paths from the roof to the rocker. Without a
support at the door joint, the Alliance suggested that the roof
strength cannot be accurately measured in these types of vehicles.
Agency Response
As part of analyzing the comments on the proposed tie-down
procedure for the quasi-static test, the agency conducted analytical
simulations using a finite element model on a late model Ford
Explorer.\27\ First the agency performed an analysis of the proposed
procedure where the vehicle was supported at the jack locations. Two
additional models were also developed to evaluate supporting the
vehicle body under the pillars and continuously along the length of the
body sill, as the commenters suggested.
---------------------------------------------------------------------------
\27\ See report, Finite Element Simulation of FMVSS No. 216 Test
Procedures, placed in the docket with this notice.
---------------------------------------------------------------------------
The Ford Explorer was modeled because it is a body-on-frame \28\
vehicle, and according to the comments, the proposed procedure would
not accurately evaluate the roof strength of that type of vehicle. The
first Explorer tie-down model followed the NPRM procedure where the
vehicle was supported at its jack point locations. This was along the
frame mounted inward of the vehicle body sill in the case of the
Explorer. The analysis showed that the NPRM procedure produced
compression of the body-to-frame rubber body mounts. We believe this
tie-down simulation did not accurately evaluate the strength of the
roof because the body was not isolated in the simulation. The loading
of the body mounts is also unrealistic in a rollover. The results were
consistent with Ford's comment that suggested supporting a vehicle by
its frame at the body mount locations could cause floor pan deformation
and thereby reduce the measured strength of the roof.
---------------------------------------------------------------------------
\28\ A body-on-frame vehicle is constructed by attaching a
vehicle body to a rigid frame which supports the drivetrain. At the
attachment points, rubber body mounts are used to isolate the body
from vibration.
---------------------------------------------------------------------------
The results of the other simulations (vehicle secured under the
pillars and vehicle secured along the rocker/sill) showed higher roof
strength than the NPRM procedure. There was nearly a 7 percent increase
in roof strength within 127 mm (5 inches) of platen travel when the
vehicle's body was supported under the pillars compared to the NPRM
procedure. The simulation results using the continuous sill support
tie-down showed a 3 percent increase in roof strength compared to the
NPRM procedure. Overall, in both simulations, the body sag in the floor
pan did not appear to be a concern and produced a more realistic
loading of the roof. The load-deformations curves were also similar,
whereas the results from the simulation using the NPRM tie-down
procedure diverged early in the analysis at approximately 18,000 N or
0.8 SWR.
We note that the full sill tie-down procedure generated a lower
peak force when compared to the vehicle supported under the pillars.
The simulation for the full sill tie-down procedure did not include any
constraints for the Explorer's frame. However, when the vehicle body
was supported under each pillar, a number of vertical supports were
added to support the mass of the frame. This could explain the slight
difference in the maximum strength of the roof. However, we believe the
difference is negligible.
After considering the comments and the computer simulations, we
decided, for purposes of fleet testing, to revise the tie-down
procedure to support the vehicle continuously under the sill. We
believe this approach further reduces any variability compared to the
Alliance recommendation because the entire wheelbase of the vehicle is
supported and not just under each pillar. Also, the peak force
difference in the computer models was not a significant issue because
both methods addressed the commenters' main concern of inappropriate
floor pan deformation. For body-on-frame vehicles, additional supports
would be placed under the frame as this constraint was not included in
the computer simulation and might account for the difference in peak
force. The full sill tie-down procedure is consistent with the existing
FMVSS No. 216 requirement supported by AIAM, Mr. Chu, Hyundai, and
Nissan.
For the fleet testing,\29\ the vehicle's sill at the body flange
weld was fully supported along the wheelbase between two box tubes and
securely fixed into place with high strength epoxy. For body-on-frame
vehicles, additional supports were placed under the frame to reduce
body sag created by an unsupported frame, as recommended by
DaimlerChrysler. Epoxy was selected in response to the Alliance, BMW
and Ford's comments that welding may adversely alter the vehicle's
structure prior to testing. We believe the epoxy will not alter the
material properties of the vehicle structure or cause complications for
sills made of non-ferrous or composite materials. The revised test
procedure provided support for each of the vehicle pillars and provided
a stable load path when tested, consistent with the recommendations by
the Alliance, DaimlerChrysler, Ford, GM and Toyota. Also, by supporting
the vehicle along the wheelbase, which includes the door seam for
vehicles without a B-pillar (the joint between the doors), a
reactionary surface is provided for the applied load when tested,
addressing the Alliance, GM and Ford's concerns.
---------------------------------------------------------------------------
\29\ See report, Two-Sided Roof Crush Strength Analysis, placed
in the docket of this notice.
---------------------------------------------------------------------------
During our evaluation of the tie-down procedure,\30\ dial
indicators were placed at the sill below the vehicle's pillars on the
opposite side of the platen travel to check for vehicle displacement
during the test. The tie-down procedure showed on average less than a
millimeter (0.04 inches) of body displacement at all measurement
locations, parallel to the direction of platen motion for both unibody
and body-on-frame vehicles. For comparison, the agency also tested a
Buick Lacrosse that was rigidly supported along the entire wheelbase
and compared the result to another Lacrosse test where the sill was
supported along the wheelbase only at 152.4 mm (6 inch) increments. The
Lacrosse was also supported under the pillars, as recommended by the
[[Page 22369]]
Alliance. The results showed that the body displacement was lower for
the full sill tie-down when compared to the results where the sill was
only partially supported.
---------------------------------------------------------------------------
\30\ The agency measured the sill displacement at three
locations along the wheelbase on the side opposite to the force
application on the roof, for 13 vehicles. Ten of the tests were
single-sided and three were two-sided. The sill displacement ranged
from 0 to 2.3 mm (0.09 inches). The VW Jetta achieved the highest
SWR level at 5.7 in this data set and experienced almost no sill
movement. In the three two-sided tests in this series, conducted
with the Subaru Tribeca and two Buick Lacrosses, the agency did not
observe any significant difference in sill displacement on the
second side compared to the first.
---------------------------------------------------------------------------
After considering the comments and in light of the testing and
simulations, we are adopting the revised tie-down procedure, where the
vehicle is supported at the sill, along the entire wheelbase. This
procedure reduces vehicle displacement, more accurately measures the
strength of the roof, and is more robust than the procedure recommended
by the Alliance and its members. Furthermore, the revised test
procedure addresses the comments to the NPRM because it supports the
vehicle pillars during testing and reduces the likelihood of vertical
and horizontal translation of the body.
We note that, in light of the fact that the test procedure is
consistent with the current FMVSS No. 216 test procedure while
providing improved clarity, the agency has adopted it for use in
current FMVSS No. 216 \31\ compliance tests. This procedure has been
used for 19 fiscal year 2007 and 2008 OVSC compliance tests.
---------------------------------------------------------------------------
\31\ TP-216-05 Laboratory Test Procedure for FMVSS No. 216,
November 16, 2006.
---------------------------------------------------------------------------
2. Platen Angle and Size
In the NPRM, we did not propose to change the test device
orientation or the size of the test plate. However, we included a
discussion of comments related to test device orientation and size that
we had received in response to the October 2001 RFC.
Under the current test procedure specified in FMVSS No. 216, the
test plate is tilted forward at a 5-degree pitch angle, along its
longitudinal axis, and rotated outward at a 25-degree angle, along its
lateral axis, so that the plate's outboard side is lower than its
inboard side. The test plate size of 762 mm (30 inches) wide by 1,829
mm (72 inches) long is designed to load the roof over the occupant
compartment. The edges of the test plate are positioned based on fixed
points on the vehicle's roof. The forward edge of the plate is
positioned 254 mm (10 inches) forward of the forwardmost point on the
roof, including the windshield trim. We note that, as discussed later
in this document, there is a secondary test procedure for certain
vehicles with raised roofs or altered roofs, which we proposed to
eliminate.
Comments
The agency received numerous comments and recommendations to change
the platen test angle and size. A number of the comments were from
safety advocacy groups. Some commenters recommending a 2-sided test
requirement recommended that we use different criteria for the two
tests.
Consumers Union cited comments it had made on the agency's 2001 RFC
and the agency's discussion in the NPRM. That commenter noted that it
had recommended that the agency modify the test plate load and size. It
stated that it continues to believe that the current plate load and
size does not reflect real-world rollover conditions. Consumers Union
stated that it believes that more of the roof crush force is absorbed
by the A-pillar than accounted for by the current or proposed
procedure. It recommended that the agency conduct additional studies
concerning this issue.
IIHS commented that testing roof crush strength at multiple load
angles would add to the meaningfulness of the quasi-static test
requirement that NHTSA currently specifies. However, it also stated
that in the absence of a range of plate angles, any distinct test angle
choice should be supported by evidence that such an angle is
representative of a significant percentage of real-world rollovers.
Various commenters recommended that the agency change the platen
pitch in ways they believe would better reflect the more aggressive
loading angles that are frequently sustained in real-world rollover
crashes, particularly for SUVs and pickups. The general recommendation
was to increase the pitch angle of the platen to 10 degrees because
commenters believed the proposed 5 degree pitch is not realistic.
CAS stated that the pitch angle must be increased to at least 10
degrees to emulate actual rollovers where damage to front fenders is
testimony to the fact that in a rollover, the pitch angles are this
high. Advocates suggested that vehicles be evaluated at different
platen angles, up to and including 10 degrees pitch x 45 degrees roll.
Mr. Chu suggested a series of procedures he believed would best
address the plate angle issue. His 6-step procedure would test each
front corner of the roof three times, with the roll angle of the plate
maintained at 25 degrees, and the pitch angle from 5 to 10 degrees.
Consumers Union and Mr. Friedman encouraged the agency to consider
the use of a smaller platen in order to load the A-Pillar and not
extensively load the B-pillar. Mr. Friedman submitted two-sided test
data published in a recent technical publication using a smaller platen
301 mm (11.8 inches) wide by 610 mm (24 inches) long and at different
pitch and roll angles.\32\ The commenter stated that the smaller plate
more aggressively loads the A-pillar. It showed the roof achieved a
lower SWR on the second side by as much as 40-70 percent compared to
the current FMVSS No. 216 procedure.
---------------------------------------------------------------------------
\32\ Friedman D., et al., ``Result From Two Sided Quasi-Static
(M216) and Repeatable Dynamic Rollover Test (JRS) Relative to FVMSS
216 Tests,'' 20th ESV Conference, Lyon, France, 2007.
---------------------------------------------------------------------------
Agency Response
After carefully considering the comments, we have decided to
maintain the current platen size and the pitch and roll angle. We note
that many of the issues raised by the commenters were ones that were
also raised in comments on the 2001 RFC.
Prior to issuing the NPRM, the agency conducted a test series to
evaluate alternative platen angles using the FMVSS No 216 platen.\33\ A
finite element study was first conducted to evaluate a range of platen
configurations and to select appropriate conditions for testing. NHTSA
tested four vehicle pairs using 5 degree x 25 degree and 10 degree x 45
degree platen angles. The peak SWR from these tests did not demonstrate
a consistent pattern between the two test conditions. For two vehicle
models, the 10 degree x 45 degree tests generated a higher peak SWR,
whereas, the 10 degree x 45 degree tests generated a lower peak SWR in
the others. Therefore, the test results were inconclusive.
---------------------------------------------------------------------------
\33\ See Docket NHTSA 2005-22143-57: Load Plate Angle
Determination and Initial Fleet Evaluation.
---------------------------------------------------------------------------
To help evaluate the comments submitted in the NPRM docket, the
agency extended the previous finite element studies to evaluate
alternative platen angles in conjunction with a smaller platen.\34\ The
finite element model of a 1997 Dodge Caravan was used to evaluate two-
sided simulations with a 5 degree x 25 degree orientation on the first
side and a 10 degree x 45 degree orientation on the second side. The
reduction in peak SWR for using a 10 degree x 45 degree platen angle on
a second side test was 18.7 percent. The 18 percent reduction in peak
SWR, while significant, is much less than the 40 to 70 percent shown in
the test results submitted to the docket. The results were also in line
with our two-sided vehicle test results using the 5 degree x 25 degree
platen orientation for both sides. On average there was an 8.7 percent
reduction of strength on the second side compared to the first.
Furthermore, we found an average
[[Page 22370]]
difference of approximately 7.1 percent lower peak force for the second
side in vehicles under 2,722 kilograms (6,000 pounds) GVWR and 14.9
percent lower peak force for the second side in vehicles over 2,722
kilograms (6,000 pounds) GVWR.
---------------------------------------------------------------------------
\34\ See, Finite Element Simulation of FMVSS No. 216 Test
Procedures, placed in the docket with this notice.
---------------------------------------------------------------------------
To evaluate how a smaller platen affects roof strength
measurements, the agency also conducted simulations with a smaller 305
x 610 mm (12 x 24 inch) platen using a 10 degree x 45 degree platen
angle on a Dodge Caravan model. The results showed an approximate six
percent decrease in peak force compared to our baseline results with a
larger platen using the same configuration. However, the simulations
showed the potential for platen edge-to-roof contact. Since the platen-
to-roof contact is intended to be a surrogate for vehicles rolling on
the ground, localized loading from the platen edge can cause
unrealistic loading conditions. Therefore, the results demonstrated how
a smaller platen localized the stress on the A-pillar, reducing the
measured strength during the evaluation, but the crush deformation does
not appear to represent real-world crash results.
Many of the commenters assumed that a higher pitch angle leads to a
more demanding test procedure and also assumed it is more reflective of
real world rollovers, particularly for pickups and SUVs. However, only
limited anecdotal evidence (based on interpretation of crash photos)
was provided to support these conclusions. Due to the extremely complex
and chaotic nature of rollover crashes, it is impossible for any one
test to fully replicate all of the loading forces that occur in all
real-world crashes. However, we believe the platen size and pitch/roll
angles proposed and currently incorporated in the standard produce roof
crush damage patterns that are representative of the crash damage
patterns observed in real-world crashes.\35\ The use of the smaller
platen would result in edge contact and unrealistic buckling of the
roof. We did not propose to alter these parameters in the NPRM or
SNPRM.
---------------------------------------------------------------------------
\35\ See Docket NHTSA 2005-22143-56: Roof Crush Analysis Using
1997-2001 NASS Case Review, 2004.
---------------------------------------------------------------------------
We are also not persuaded by commenters that recommended varying
the pitch and roll angle in a two-sided test. As discussed above, the
agency conducted analytical simulations varying the platen angles.
Based on the similarity of the post test damage pattern in that
research, there was not sufficient evidence to justify changing the
load plate configuration from our current protocol. We are further not
persuaded by CFIR, Mr. Chu, and LSSM comments to require testing on
both sides with a smaller platen size. Analytical simulations \36\
conducted by the agency using a Dodge Caravan showed that a smaller
platen is sensitive to positioning and can result in edge contact. As a
result, a smaller test plate can produce unrealistic contact with the
roof and highly localized loading, inconsistent with real world
rollover crashes. CFIR's finding of a 40-70 percent reduction in roof
strength for the second side tests it conducted may be attributed to
its smaller platen adding unrealistic stress on the roof.
---------------------------------------------------------------------------
\36\ See, Finite Element Simulation of FMVSS No. 216 Test
Procedures, placed in the docket with this notice.
---------------------------------------------------------------------------
3. Testing Without Windshields and/or Other Glazing in Place
We did not propose to change the current FMVSS No. 216 procedure
and test the vehicle without the windshield or side windows in place.
In the NPRM, we stated:
The agency believes that windshields provide some structural
support to the roof even after the windshield breaks because the
force-deflection plots in some of the recent test vehicles (e.g.,
Ford Explorer, Ford Mustang, Toyota Camry, Honda CRV) show little or
no drop off in force level after the windshield integrity was
compromised. Further examination of real-world crashes indicates
that the windshield rarely separates from the vehicle, and
therefore, does provide some crush resistance. Because NHTSA
believes that the vehicle should be tested with all structural
components that would be present in a real-world rollover crash, we
decline to propose testing without the windshield or other glazing.
70 FR 49238.
A number of commenters, including ones from safety advocacy groups,
questioned the contribution of the windshield to the overall strength
of the roof and generally recommended the windshield be removed prior
to the test. Advocates, Boyle, et al., CFIR, Consumers Union,
DVExperts, IIHS, Public Citizens, Penn Engineering, and Perrone
commented that windshields often break in a rollover, and stated that
the agency should not specify a test procedure with windshields in
place. Consumers Union expressed concern about aftermarket windshield
installation and the unquantifiable strength of the windshield in a
crash. The Engineering Institute (EI) and Mr. Hauschild recommended
that if the agency maintains the 2.5 SWR requirement then the
windshield should be removed. Mr. Slavik stated he conducted tests
which confirm that on some vehicles, damage to the windshield
significantly reduces the force and energy required to produce an
incremental amount of intrusion.
Technical Services recommended that the side window glass should be
required to be preserved during testing to improve vehicle rollover
performance. Xprts and Mr. Friedman also recommended that the side
windows should not be permitted to fail during the test. Both
commenters referenced Volvo's internal criteria and suggested that
tempered glass windows can remain intact.
ARCCA, Consumer Union, Specialty Equipment Market Association
(SEMA) and Hyundai raised concerns with regard to vehicles equipped
with sunroofs. ARCCA and Consumers Union suggested vehicles equipped
with sunroofs meet the roof crush requirements. Hyundai noted that
vehicles equipped with sunroofs have reduced headroom compared with
those without sunroofs. SEMA requested the agency ensure aftermarket
sunroofs be permitted because they are installed inside the roof's
perimeter cage.
Agency Response
After considering the comments, we decline to change the current
test procedure in which the windshield and side windows remain in place
during FMVSS No. 216 tests. We also disagree with the recommendation
that the agency require side windows to be preserved during test. The
agency was not presented with new information showing windshield
breakage in a rollover significantly contributed to a reduction in roof
strength.
We have examined the post crash windshield status for 1997-2006
NASS investigated rollover crashes with greater than one quarter turn.
The majority of the windshields were coded as either ``in place and
cracked'' or ``in place and holed.'' Less than 10 percent of weighted
incidents indicate the windshield is ``out of place.''
While Mr. Slavik stated he conducted testing, the agency was not
provided data to evaluate. He asserted that there is anecdotal
acknowledgement by some manufacturers that the windshield provides
upwards of 30 percent of the measured roof strength. We note that that
the agency's testing showed that windshield breakage has not been a
factor in the maximum strength of the roof for some vehicles.\37\ The
peak load continued to increase after windshield breakage in the
testing of the 2003 Ford Focus, 2003 Chevrolet Cavalier, and 2002
Nissan Xterra. In the case of the
[[Page 22371]]
Cavalier, the windshield did not contribute to a decrease in strength
until 170 mm (6.7 inches) of platen travel.
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\37\ See NHTSA-2005-22143-0049: Roof Crush Research: Phase 3--
Expanded Fleet Evaluation.
---------------------------------------------------------------------------
The windshield is a structural element for some vehicles, and we
continue to believe that vehicles should be tested with all structural
components that would be present in a real-world rollover crash. We
declined to propose testing without the windshield or other glazing for
that reason, and we are not persuaded that there is sufficient
justification to revise our position.
The agency also wanted to ascertain the influence of sunroofs on
roof strength. The Scion tC, Cadillac SRX and Ford Edge were tested
with large panoramic sunroofs. The glass panel sunroof in the Scion tC
shattered during the two-sided test, yet the glass panel in the SRX did
not fail during the single-sided only test. After review of the load-
deformation curves for both vehicles, the test results showed the
effect of the sunroof was insignificant to the overall strength of the
roof. In the case of the Scion tC, at the point when the sunroof glass
broke during the first side test, there was no change in the platen
load. In the case of the Ford Edge, the rear glass panel of the sun
roof failed in the second-sided test; however, the front glass panel
over the front row occupants remained intact. This occurred well after
125 mm of platen travel. As a result, we believe it is practicable for
vehicles with sunroofs (including large panoramic roofs) to meet the
requirements and we do not foresee this upgrade inhibiting aftermarket
sunroofs mounted within the roof structure.
In response to Consumers Union, the possibility exists that
aftermarket windshield installations may not perform to OEM standards.
However, we do not believe this possibility justifies changing roof
strength requirements for all new vehicles.
Xprts and Mr. Friedman recommended a requirement that the side
windows not break during the roof strength test. The agency
investigated the contribution of side windows to the strength of the
roof structure. Our testing showed that side window breakage is
directly correlated to platen displacement with limited effect on the
strength of the roof. In reviewing the load-deformation curves at the
point where the side glass breaks, there is no measurable drop in load
of the roof and it generally occurs well after the peak strength of the
roof has been reached.\38\ For completeness, the agency also assessed
the impact of rear window breakage. The rear windows broke well after
peak strength was reached and generally past 127 mm (5 inches) of
platen travel. The breakage of the rear window glass resulted in a
slight drop in the strength of the roof particularly in pick-up trucks
where the vertical glass is loaded by the test device and can add some
strength. Overall, the impact of the side and rear glass had little
impact on the strength of the roof. We also note that such a
requirement is outside the scope of notice of the proposal.
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\38\ Ibid.
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4. Deletion of Secondary Plate Positioning Procedure
In the NPRM, we proposed to apply the primary plate procedure for
all vehicles, removing the secondary plate procedure that applies to
some raised and altered roof vehicles. We explained that the secondary
plate positioning procedure produces rear edge plate loading onto the
roof of some raised and altered roof vehicles that may cause excessive
deformation uncharacteristic of real-world rollover crashes. Because an
optimum plate position cannot be established for all roof shapes, the
testing of some raised and altered roof vehicles will result in loading
the roof rearward of the front seat area. We stated that we believe
this is preferable to edge contact because edge contact produces
localized concentrated forces upon the roof typically resulting in
excessive shear deformation of a small region. We also stated that we
believe that removing the secondary plate position would make the test
more objective and practicable.
Advocates was the only commenter on this issue and opposed
eliminating the secondary plate positioning. It stated that reverting
back to the primary plate position for aerodynamic roof vehicles would
induce unrealistic loads in that the proportion of force applied to the
roof is excessively concentrated over the B-pillars. It stated that as
a consequence, test conditions and roof response to plate loading can
be substantially different than the loading that actually occurs in
real-world rollovers of these vehicles where the A-pillars receive a
proportionately greater force. Advocates suggested this is crucial
because some vehicles with severely sloped A-pillars are candidates for
A-pillar collapse in rollover crashes and the percentage of new
vehicles with severely raked A-pillars and aerodynamically sloped roofs
has increased each year since their use began in the early to mid-
1990s.
Agency Response
After considering Advocates' comment, we have decided to remove the
secondary plate procedure. We do not agree that the FMVSS No. 216
platen size and positioning produces unrealistic loading of aerodynamic
roofs. This issue was considered in the 1999 final rule (64 FR 22567)
where the agency adopted a revised platen positioning procedure to
reduce the likelihood of unrealistic loading on vehicles with rounded
roofs. The agency's recent testing of modern vehicles has shown the
current plate positioning procedure does distribute the load between
the A- and B-pillars. Generally, the plate's initial point of contact
with the roof is slightly behind the A-pillar including the Volvo XC90
which had a large amount of curvature to the roof in the test area
compared to most vehicles tested.
However, we continue to believe that edge contact induced by the
secondary plate procedure results in unrealistic loading specifically
when the roof is raised or altered. In some circumstances, the plate
will essentially punch through the sheetmetal instead of loading the
roof structure. We also do not believe vehicles with steeply raked A-
pillars are common architectures for raised and altered roof vehicles.
Vans with more upright A-pillars are generally modified to have their
roofs raised or altered. We are not aware of such changes to
traditional passenger cars with steeply raked A-pillars.
5. Removal of Roof Components
FMVSS No. 216 currently specifies removal of roof racks prior to
platen positioning or load application. We did not propose to change
this provision.
Xprts recommended that the roof be tested as the vehicle is to be
sold, with roof racks or other equipment in place. That commenters
stated that removal of roof racks prior to conducting the roof crush
test eliminates a typical roof failure mode. It states that roof rack
mountings initiate buckling of the roof, increasing the risk of
occupant injury from roof panel buckling.
After considering this comment, we decline to change the current
test procedure. No data were provided by Xprts to support its
contention that roof racks result in a typical roof failure mode and
thereby increase the risk of occupant injury from roof panel buckling.
We reviewed several NASS-CDS cases \39\ of utility vehicles with roof
racks that had undergone rollover crashes. Our review did not support
the contention that the presence of a roof rack initiated buckling of
the roof and increased the risk of occupant injury. There was also no
general trend
[[Page 22372]]
concerning injury severity and presence of a roof rack in the reviewed
cases.
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\39\ Photographs collected from NASS-CDS Case Query Page. NASS-
CDS cases examined: 100121, 102005185, 146004985, 161005827,
656500082, 471300143, and 129005218.
---------------------------------------------------------------------------
We further reviewed our fatal hardcopy case files \40\ and could
not identify a single case where the roof rack appeared to aggravate
the deformation of the roof structure.
---------------------------------------------------------------------------
\40\ See Docket Number NHTSA 2005-22143-56: Roof Crush Analysis
Using 1997-2001 NASS Case Review.
---------------------------------------------------------------------------
6. Tolerances
In response to comments from the Alliance and Chrysler LLC, we are
adding several tolerances in the regulatory text to help improve test
repeatability. We note that platen angles are measured from the
horizontal and not from the vehicle's frame of reference. Measuring
platen angles with respect to the ground is more objective than using
the test vehicle's frame of reference because the latter would
introduce manufacturing variability. We note that we are not including
a specification concerning platen overshoot on the first side test
since we will not conduct compliance tests beyond the specified SWR.
We decline to add a calibration procedure for the test device or to
make changes relating to load application rate or to add platen
material specifications. The basic FMVSS No. 216 test procedure has
been used for many years, and the commenters did not provide persuasive
evidence that changes are needed in these areas. As to platen
materials, we believe the current specification for a rigid unyielding
block is sufficient.
c. Requirements for Multi-Stage and Altered Vehicles
For vehicles manufactured in two or more stages,\41\ other than
vehicles incorporating chassis-cabs,\42\ we proposed to give
manufacturers the option of certifying to either the existing roof
crush requirements of FMVSS No. 220, School Bus Rollover Protection, or
the new roof crush requirements of FMVSS No. 216. FMVSS No. 220 uses a
horizontal plate, instead of the angled plate of Standard No. 216.
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\41\ Vehicles manufactured in two or more stages are assembled
by several independent entities with the ``final stage''
manufacturer in most cases assuming the ultimate responsibility for
certifying the completed vehicle.
\42\ Under 49 CFR Sec. 567.3, chassis-cab means an incomplete
vehicle, with a completed occupant compartment, that requires only
the addition of cargo-carrying, work-performing, or load-bearing
components to perform its intended functions.
---------------------------------------------------------------------------
As explained in the NPRM, multi-stage vehicles are aimed at a
variety of niche markets, most of which are too small to be serviced
economically by single stage manufacturers. Some multi-stage vehicles
are built from chassis-cabs that, by definition, have a completed
occupant compartment. A chassis-cab's roof is an integral part of its
body structure surrounding the seats for the occupants. Other vehicles
are built using incomplete vehicles that do not have a completed
occupant compartment. These include a van cutaway, which consists of
the frame, drive train, steering, suspension, brakes, axles, and the
front body section of a van that has no body structure behind the two
front seats. Another example is a stripped chassis. A final stage
manufacturer would typically complete the occupant compartments of
these incomplete vehicles by adding body components to produce a truck
(e.g., work truck) or multipurpose passenger vehicle (e.g., motor
home).
In developing our proposal, we considered whether the proposed
standard would be appropriate for the type of motor vehicle for which
it would be prescribed. We stated that we believed it was appropriate
to consider incomplete vehicles, other than those incorporating
chassis-cabs, as a vehicle type subject to different regulatory
requirements. We anticipated that final stage manufacturers using
chassis cabs to produce multi-stage vehicles would be in position to
take advantage of ``pass-through certification'' of chassis-cabs, and
therefore did not believe the option of alternative compliance with
FMVSS No. 220 was appropriate.
We noted that while we believed that the requirements in FMVSS No.
220 have been effective for school buses, we were concerned that they
may not be as effective for other vehicle types. As noted above, the
FMVSS No. 216 test procedure results in roof deformations that are
consistent with the observed crush patterns in the real world for light
vehicles. Because of this, we explained that our preference would be to
use the FMVSS No. 216 test procedure for light vehicles. We believed,
however, that this approach would fail to consider the practicability
problems and special issues for multi-stage manufacturers.
We stated that in these circumstances, we believed that the
requirements of FMVSS No. 220 appeared to offer a reasonable avenue to
balance the desire to respond to the needs of multi-stage manufacturers
and the need to increase safety in rollover crashes. Several states
already require ``para-transit'' vans and other buses, which are
typically manufactured in multiple stages, to comply with the roof
crush requirements of FMVSS No. 220. These states include Pennsylvania,
Minnesota, Wisconsin, Tennessee, Michigan, Utah, Alabama, and
California. We tentatively concluded that these state requirements show
the burden on multi-stage manufacturers for evaluating roof strength in
accordance with FMVSS No. 220 is not unreasonable, and applying FMVSS
No. 220 to these vehicles would ensure that there are some requirements
for roof crush protection where none currently exist.
Comments
We received comments concerning requirements for multi-stage and
altered vehicles from Advocates, NTEA, NMEDA and RVIA.
Advocates stated that it opposes permitting FMVSS No. 220 as an
alternative for multi-stage vehicles. It claimed that FMVSS No. 220 is
a ``weak'' standard whose effects on roof strength in actual rollover
crashes are mostly unknown.
NTEA recommended that all multi-stage vehicles be excluded from
roof crush resistance requirements. It stated that manufacturers of
non-chassis-cab vehicles will not be able to conduct the tests or
perform engineering analysis to ensure conformance to FMVSS No. 220.
NTEA also disagreed with the assumption that the presence of state
requirements for FMVSS No. 220 compliance demonstrates that final stage
manufacturers can actually comply. It stated that the ability of school
bus and para-transit bus manufacturers to comply with FMVSS No. 220
does not reflect the ability of typical final stage manufacturers to
comply with FMVSS No. 220.
NTEA also stated it is impractical for the agency to assume
manufacturers of multi-stage vehicles built on chassis-cabs will be
able to use pass-through certification for compliance. That
organization stated that these type of vehicles are generally unique
and built to customer specifications. It also raised a concern that
some manufacturers of chassis-cabs may not provide the necessary
specifications for the final stage manufacturer to rely on pass-through
certification as it applies to roof strength. It argued that the final
stage manufacturer would therefore be responsible for conducting costly
analysis and testing to verify compliance with FMVSS No. 216.
NMEDA expressed concern that the FMVSS No. 220 option would only be
available for multi-stage vehicles. It asked that the FMVSS No. 220
option be extended to raised or altered roof vehicles. To encompass the
modifiers in the proposed upgrade to FMVSS No. 216, NMEDA asked that a
vehicle roof that is altered after first retail sale be considered in
compliance if it meets the requirements of FMVSS No. 216 or
[[Page 22373]]
FMVSS No. 220. NMEDA also stated that raising a roof increases the
available headroom and that the roof therefore can crush more before
there is any contact with an occupants head. NMEDA requested the agency
account for the additional headroom beyond the original vehicle's
headroom in establishing any requirement.
RVIA supported our proposal to permit FMVSS No. 220 as an option
for small motor homes as this would allow manufacturers to address the
unique issues concerning such specialized vehicles built in two or more
stages.
Agency Response
After carefully considering the comments and as explained below, we
are providing a FMVSS No. 220 option for multi-stage vehicles, except
those built on chassis-cab incomplete vehicles, and for vehicles which
are changed in certain ways to raise the height of the roof. For
example, a van may be altered by replacing its roof with a taller
structure (referred to as a raised roof) to better accommodate a person
in a wheelchair. We are also excluding a narrow category of multi-stage
vehicles from FMVSS No. 216 altogether, multi-stage trucks built on
incomplete vehicles other than chassis cabs.
In discussing the issues raised by commenters, we begin by
addressing the comment of Advocates. That organization opposed
permitting FMVSS No. 220 as an alternative for multi-stage vehicles
because it believes that FMVSS No. 220 is not sufficiently stringent
and that its effects on actual rollover crashes are mostly unknown.
As we discussed in the NPRM, we believe the requirements in FMVSS
No. 220 have been effective for school buses, but we are concerned that
they may not be as effective for other vehicle types. We explained that
our preference would be to use the FMVSS No. 216 test procedure for
light vehicles, but that this approach would fail to consider the
practicability problems and special issues for multi-stage
manufacturers.
Advocates did not provide analysis or data addressing the special
circumstances faced by multi-stage manufacturers, or explain why it
believes these manufacturers can certify compliance of their vehicles
to FMVSS No. 216. Therefore, that commenter has not provided a basis
for us to take a different position than we took in the NPRM.
We next turn to the issues raised by NTEA. As a general matter, we
believe that it is neither necessary nor would it be appropriate to
exclude all multi-stage vehicles from roof crush resistance
requirements. The purpose of FMVSS No. 216 is to improve occupant
safety in the event of a rollover. If a multi-stage vehicle is involved
in a rollover, the vehicle's roof strength will be an important factor
in providing occupant protection. Therefore, while we seek to address
the special needs and circumstances of multi-stage manufacturers, we
decline to provide any blanket exclusion for all multi-stage vehicles.
We will address the issues raised by that commenter separately for
multi-stage vehicles built on chassis-cab incomplete vehicles, multi-
stage trucks with a GVWR greater than 2,722 kilograms (6,000 pounds)
not built on a chassis cab and not built on an incomplete vehicle with
a full exterior van body, and other multi-stage vehicles not built on
chassis cabs.
Multi-stage vehicles built on chassis-cab incomplete vehicles.
A chassis-cab is an incomplete vehicle, with a completed occupant
compartment, that requires only the addition of cargo-carrying, work-
performing, or load-bearing components to perform its intended
functions. As such, chassis-cabs have intact roof designs. Chassis-cabs
are based on vehicles that are sold as complete vehicles, e.g., medium
and full size pickup trucks, so their roof structure will be designed
to meet the upgraded requirements of FMVSS No. 216.
After considering the comments of NTEA, we believe that final stage
manufacturers can rely on the incomplete vehicle documents (IVD) for
pass-through certification of compliance with FMVSS No. 216 for
vehicles built using chassis cabs. To do this, final stage
manufacturers will need to remain within specifications contained in
the IVD. Since the stringency of FMVSS No. 216 is dependent on a
vehicle's unloaded vehicle weight, the final stage manufacturer would
need to remain within the specification for unloaded vehicle weight. If
they did not, the roof would not likely have the strength to comply
with FMVSS No. 216. Also, final stage manufacturers will need to avoid
changes to the vehicle that would affect roof strength.
We note that some changes made by final stage manufacturers could
affect the ability to conduct an FMVSS No. 216 test, e.g., for a truck,
the addition of a cargo box structure higher than the occupant
compartment, which could interfere with the placement of the FMVSS No.
216 test device. To address this concern, we are including a
specification in the final rule that such structures are removed prior
to testing. (They are still counted as part of a vehicle's unloaded
weight.)
Multi-stage trucks with a GVWR greater than 2,722 kilograms (6,000
pounds) not built on a chassis cab and not built on an incomplete
vehicle with a full exterior van body.
We have decided to exclude from FMVSS No. 216 a very limited group
of multi-stage trucks with a GVWR greater than 2,722 kilograms (6,000
pounds), ones not built on a chassis cab and ones not built on an
incomplete vehicle with a full exterior van body. We note that some
incomplete vehicles with a full exterior van body might not be included
in the definition of chassis-cab but would still have an intact roof
design.
For the reasons discussed in the previous section, final stage
manufacturers can rely on the IVD for pass-through certification of
compliance with FMVSS No. 216 for vehicles built using chassis cabs.
For multi-stage trucks built on an incomplete vehicle with a full
exterior van body, the manufacturer can rely on either the IVD for
pass-through certification of compliance with FMVSS No. 216, or use the
FMVSS No. 220 option. Since the incomplete vehicle will have an intact
roof design and will be similar to ones sold as non-multi-stage
vehicles, the roof will have been designed to comply with FMVSS No.
216. Therefore, it is likely that the final stage manufacturer can pass
through FMVSS No. 216 certification. Since the vehicle at issue will be
based on an incomplete vehicle with a full exterior van body, the FMVSS
No. 220 procedure is likely to also be an appropriate one for the final
stage vehicle.
We are concerned, however, that for other multi-stage trucks, e.g.,
van cutaways, there may be practicability problems for final stage
manufacturers. Because the incomplete vehicle will not have an intact
roof and because the strength of the roof may be dependent on the
structure to be added by the final stage manufacturer, the incomplete
vehicle manufacturer may not provide IVD or similar information that
would permit pass-through certification. Moreover, the design of the
completed truck may be such that it is not possible to test the vehicle
to FMVSS No. 216 (due to interference with the FMVSS test device) or
inappropriate for testing with FMVSS No. 220. As noted earlier, the
FMVSS No. 220 test was designed for school buses and uses a horizontal
plate over the driver and passenger compartment instead of the angled
plate of Standard No. 216. This test may not be appropriate for a truck
with a cargo box that is higher than the occupant compartment.
Given these practicability issues, we have decided to exclude this
limited
[[Page 22374]]
group of multi-stage trucks from the requirements of FMVSS No. 216.
Other multi-stage vehicles not built on chassis cabs.
For other multi-stage vehicles not built on chassis cabs, we
continue to believe, for the reasons discussed in the NPRM, that
permitting FMVSS No. 220 as an option is a reasonable way to balance
the desire to respond to the needs of multi-stage manufacturers and the
need to increase safety in rollover crashes. As we noted, several
states already require ``para-transit'' vans and other buses, which are
typically manufactured in multiple stages, to comply with the roof
crush requirements of FMVSS No. 220. We also note that RVIA supported
our proposal.
Multi-stage vehicles and complete vehicles with a GVWR greater than
2,722 kilograms (6,000 pounds) which have been changed by raising their
original roof.
In response to the comments of NMEDA, we agree that the FMVSS No.
220 option should be available to multi-stage and complete vehicles
with a GVWR greater than 2,722 kilograms (6,000 pounds) which have been
changed by raising their original roof.
In considering this issue, we note that in 1999 the agency
published a final rule (64 FR 22567) that was in part in response to an
RVIA petition to allow vans, motor homes and other multipurpose
vehicles with raised roofs the option to certify to FMVSS No. 220. The
RVIA had argued first that since raised roof vehicles would have met
FMVSS No. 216 requirements prior to modification of their roofs, the A-
Pillar strength has already been demonstrated. Second, RVIA had claimed
that the modifications usually do not affect the roof strength near the
A-pillar. RVIA believed that the FMVSS No 220 test procedure could be
used to test the strength of the entire modified vehicle roof without
repeating the FMVSS No. 216 certification test. In the final rule, we
stated that we disagreed with RVIA's analysis that concluded FMVSS No.
220 is comparable to FMVSS No. 216 and is preferable for testing
vehicles with raised or modified roofs. We stated that that the agency
stood by its tentative conclusions stated in the NPRM that the FMVSS
No. 220 test is less stringent than FMVSS No. 216 for testing the
appropriate roof area.
In considering the issues raise by NMEDA, we note that the
discussion we included in the 1999 final rule was in the context of the
version of FMVSS No. 216 that existed at that time. The standard was
applicable to vehicles with a GVWR of 2,722 kilograms (6,000 pounds) or
less. Here we are discussing vehicles with a GVWR greater than 2,722
kilograms (6000 pounds).
We believe that practicability issues arise for vehicles with a
GVWR greater than 2,722 kilograms (6,000 pounds) whose roofs are
raised. Moreover, we believe that the FMVSS No. 220 option is
appropriate for the ``para-transit'' vans and buses. The FMVSS No. 220
option will help ensure that these occupants are afforded a level of
protection that is currently not required. We are not providing this
option to vehicles with raised roofs and a GVWR of less than or equal
to 2,722 kilograms (6,000 pounds).
We believe that the practicability issues for vehicle alterers
which raise roofs on the vehicles at issue are comparable to those of
final stage manufacturers. An alterer may raise a roof on a vehicle
that was originally certified to FMVSS No. 216. We believe that
permitting alterers which raise roofs on these vehicles the option of
certifying to FMVSS No. 220 balances potential practicability issues
with the need to increase safety in rollovers.
The FMVSS No. 220 130 mm (5.1 inches) limit of platen travel
established at the point of contact with the raised roof is consistent
with FMVSS No. 216 requirements. As discussed elsewhere in this
document, we are maintaining the current platen travel requirement as
well as adding a headroom requirement in FMVSS No. 216. Therefore, even
if a roof is raised and the manufacturer or alterer selects the FMVSS
No. 220 option, we believe the platen travel requirement should be the
same, even if there is additional headroom.
In arguing for an alternative requirement in this area, NMEDA
raised a concern about higher center of gravity. NMEDA surveyed its
members to obtain, amongst a number of things, an estimate of the
height of raised roofs. It found that some raised roofs can be as high
as 762 mm (30 inches). It was concerned about the resulting center of
gravity's effect on rollover propensity of these vehicles.
We note that in raising the roof of a vehicle, a final stage
manufacturer or alterer will likely increase the center of gravity of
the vehicle, independent of any roof crush resistance requirements. We
believe that it is important that manufacturers carefully analyze the
impacts of their changes, and choose appropriate vehicles for such
modifications. We also believe that if final stage manufacturers or
alterers raise the roof of a vehicle, it is still necessary that the
vehicle have appropriate roof strength to provide protection in
potential rollovers.
As to NMEDA's specific recommendation, we believe that organization
has not demonstrated a need for a different requirement in this area.
According to that organization, the typical height of a raised roof is
356-406 mm (14-16 inches). Its members have designed raised roofs that
meet FMVSS No. 220, and FMVSS No. 216 as amended will permit this
option. In addition, vans which are typically altered or modified in
this manner will have an electronic stability control system as
standard equipment. Also, different vehicles can be used for higher
raised roofs, i.e., those with dual rear wheels. We note that the GVWR
of those vehicles is greater than 4,536 kg (10,000 pounds) and FMVSS
No. 216 would not apply.
d. Other Issues
1. Convertibles and Open Bodied Vehicles
Convertibles are excluded from the requirements of FMVSS No. 216.
In the NPRM, we sought to clarify the definition and scope of exclusion
for convertibles.
We explained that FMVSS No. 216 does not define the term
``convertible.'' We noted, however, that S3 of 49 CFR 571.201 defines
convertibles as vehicles whose A-pillars are not joined with the B-
pillars (or rearmost pillars) by a fixed, rigid structural member. In a
previous rulemaking, NHTSA stated that ``open-body type vehicles'' \43\
are a subset of convertibles and are therefore excluded from the
requirements of FMVSS No. 216.\44\
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\43\ An open-body type vehicle is a vehicle having no occupant
compartment top or an occupant compartment top that can be installed
or removed by the user at his convenience. See Part 49 CFR 571.3.
\44\ See 56 FR 15510 (April 17, 1991).
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We stated in the NPRM that we had reassessed our position with
respect to ``open-body type vehicles.'' Specifically, we believed that
we were incorrect in stating that ``open-body type vehicles'' are a
subset of convertibles because some open-body type vehicles do not fall
under the definition of convertibles in S3 of FMVSS No. 201. We cited
the example of a Jeep Wrangler, which we believed to have a rigid
structural member that connects the A-pillars to the B-pillars.
We stated in the NPRM that we believe that ``open-body type
vehicles are capable of offering roof crush protection over the front
seat area.'' Accordingly, we proposed to limit the exclusion of
convertibles from the requirements of FMVSS No. 216 to only those
vehicles whose A-pillars are not
[[Page 22375]]
joined with the B-pillars, thus providing consistency with the
definition of a convertible in S3 of FMVSS No. 201. We proposed to add
the definition of convertibles contained in S3 of 49 CFR Sec. 571.201
to the definition section in FMVSS No. 216.
Comments
The agency received comments on this issue from Advocates, the
Alliance, AIAM, BMW, DaimlerChrysler, Ferrari and Porsche. Vehicle
manufacturers supported continuing to exclude convertibles from the
requirements; however they raised some concerns with regard to the
proposed definition. The Alliance commented that there is no evidence
that it is practicable for convertibles or open body vehicles to
comply.
DaimlerChrysler disagreed with the agency's position that the
Wrangler is not a convertible. It claimed that the Wrangler does not
have an A-pillar, since the structure is not rigid and is hinged to
fold down. Further, that company stated that the padded tube connecting
the windshield frame and the sport bar is not rigid because it is
attached with easily-removable screws.
Several commenters addressed the proposed definition of
convertible. Ferrari suggested that the definition of convertible
include ``above the window opening light lowermost point.'' AIAM
recommended two changes: to add ``not permanently joined'' and to make
it clear that the referenced connection is ``above the lowest point of
the side window opening.'' This would lead to the following complete
definition: ``A convertible is a vehicle whose A-pillars are not
permanently joined with the B-pillars (or rearmost pillars) by a fixed,
rigid structural member above the lowest point of the window opening.''
DaimlerChrysler suggested changing the convertible definition to
``vehicles with folding tops or removable hardtops with A-pillars not
joined to the B-pillars (or rearmost pillars) or joined with removable
parts to the B-pillars (or rearmost pillars).''
Advocates disagreed with excluding convertibles from FMVSS No. 216
and stated further that the agency should establish rollover
requirements for convertibles that limit ejections and head and neck
injuries.
Agency Response
After considering the comments, we are adopting the proposed
definition of convertible for the final rule and we are continuing to
exclude convertibles within that definition from the FMVSS No. 216
requirements. This includes retractable hard top convertibles. We
believe that to establish a roof crush requirement on vehicles that do
not have a permanent roof structure would not be practical from a
countermeasure perspective. A convertible roof would have to be strong
enough to pass the quasi-static test, yet flexible enough to fold into
the vehicle. Since we are not aware of any such designs, we do not
agree with Advocates on this point. We also note that new rollover and
ejection requirements for convertibles are outside the scope of this
rulemaking.
On the issue of open-body vehicles, we agree with DaimlerChrysler
that the agency misidentified the Wrangler as an open-body vehicle in
the NPRM when it should have been considered a convertible (since the
A-pillar is not rigid and fixed to the B-pillar or other rearmost
pillar). At the time, we were unaware that the windshield and support
bars were designed to be disassembled.
Our position on open-body vehicles has not changed. Under the new
definition, open-body vehicles will be subject to FMVSS No. 216, since
they are capable of offering roof crush protection over the front seat
area. We note, however, that given DaimlerChrysler's comment about the
Jeep Wrangler, we are not aware of other vehicles currently available
for sale that are considered open-body vehicles.
We disagree with the Alliance's assertion that it is not
practicable for open-body vehicles to meet the requirements of FMVSS
No. 216. We believe that if a vehicle otherwise similar to the Wrangler
had roof supports that are fixed (as in a roll cage), it should be
capable of providing protection to the occupants as required by today's
final rule.
We are also not making the changes to the proposed definition of
convertible suggested by some commenters. The definition proposed was
previously adopted in FMVSS No. 201 (62 FR 16725), and the agency
believes the applicability is the same and is unaware of any concerns.
Furthermore, we do not believe further specificity is warranted given
our revised position on the Wrangler. We believe our discussion in the
NPRM concerning the Wrangler may have caused confusion. We also do not
agree that there is a need to specify that convertibles have folding
hardtops or removable hardtops. These roof systems are not intended as
significant structural elements but are designed primarily to provide
protection from inclement weather, improve theft protection and are
generally offered as a luxury item. These types of roof systems are
also designed of lighter weight materials, such as aluminum or
composites, for ease of folding and storage within the vehicle or
removal by the consumer. and we believe consumers readily recognize
they will afford the occupants limited protection in a rollover.
2. Vehicles Without B-Pillars
In the NPRM, we did not specifically discuss vehicles that are
designed without B-pillars. At the time we were unaware of any
technical concerns the manufacturers might have with these vehicle, to
meet the proposed requirements.
Ford identified a number of design challenges for vehicles without
B-pillars. That company's concerns were focused on pickup trucks
without B-pillars that have a GVWR of 3,856 kilograms (8,500 pounds) or
more. These vehicles have a front-forward opening and a rear-rearward
opening side door configuration that latch together without a fixed,
structural B-pillar. Ford expressed concern that there is no direct
load path to resist the platen during testing and as a result, there
are significant design and manufacturing issues that must be addressed
while avoiding a major incremental weight penalty. Ford did not make
any specific recommendations.
Agency Response
We agree with Ford's analysis that certain vehicles without B-
pillars may raise additional technical challenges compared to other
vehicles, particularly for heavier vehicles. However, based upon our
fleet testing, we believe that a structure can be designed at the joint
between the doors that acts as a surrogate B-pillar to resist roof
displacement during testing. We note that the Alliance's comments on
how the proposed tie-down procedure adversely affects vehicles without
B-pillars reinforce this view. The revised tie-down procedure for the
final rule will aid vehicles without B-pillars in complying since
support will be placed along the complete body sill.
NHTSA tested two vehicles without B-pillars, the 2004 Chevrolet
Silverado HD and 2005 Nissan Frontier. This testing confirmed that the
load can be successfully transferred to the joint between adjacent
doors where a B-pillar would be in a conventional vehicle design. The
Silverado did not meet the 2.5 SWR proposed in the NPRM, but it did
exceed 1.5. The Frontier achieved a peak SWR of almost 4.0 within the
allocated platen displacement.
While we appreciate the challenges manufacturers will incur to meet
the new requirements, we believe the upgrade is feasible for vehicles
without B-pillars. We note that one of the
[[Page 22376]]
reasons we are providing a phase-in is to permit manufacturers
additional time to make the design changes needed to enable some of the
more challenging vehicles to comply with the requirements of the final
rule.
3. Heavier Vehicles With a High Height to Width Aspect Ratio
The Alliance and Mercedes-Benz USA requested that vehicles with a
GVWR above 3,856 kilograms (8,500 pounds) GVWR and a height to width
aspect ratio greater than 1.2 be permitted to certify to FMVSS No. 220
as an option or, at a minimum, use the larger platen specified for
FMVSS No. 220. They argued that the FMVSS No. 216 platen results in
unrealistic roof deformation for these particular vehicles.
Agency Response
While we have considered this comment, we believe that the
commenters have not provided persuasive evidence that a special
requirement is needed for these vehicles. While we did observe edge
contact in our testing of the Sprinter, it was not of a nature that
prevents compliant designs. We note that the 1.5 SWR we are adopting
for vehicles within this weight range reduces possible concerns in this
area.
4. Active Roofs
Autoliv North America (Autoliv) stated that the quasi-static test
procedure does not have a provision for active roof structure systems.
Active roof structures are being developed to provide added stiffness
during an actual rollover event. The effectiveness of such a system may
be transient, deployed during a rollover initiation and lasting only as
long as required to reduce intrusion. The quasi-static test specifies a
deformation rate of not more than 13 millimeters per second with the
total time for crush not to exceed 120 seconds. According to Autoliv,
the duration of this test may exceed the time in which certain active
roof structures can be effective.
Agency Response
We are not aware of the near term implementation or effectiveness
of active roof structure technology. In developing performance
requirements, we seek to develop ones that are appropriate for, and do
not unnecessarily discourage, new technologies. However, our ability to
do this is dependent on the amount of information we have. We do not
have sufficient information at this time to indicate the quasi-static
test will prevent implementation of active roof systems.
5. Whether an Additional SNPRM Is Needed
Several commenters argued that the agency's January 2008 SNPRM did
not provide sufficient information about the alternatives we were
considering and that an additional SNPRM should be published.
Public Citizen claimed that the January 2008 SNPRM failed to
provide enough information for meaningful public comment. It stated
that the agency did not spell out the explicit safety benefits of
mandating a two-sided test, or how using the one-sided test would meet
the statutory requirement relating to roof strength for driver and
passenger sides. Public Citizen argued that a new SNPRM is needed.
Advocates claimed that the January 2008 SNPRM offered several
regulatory alternatives without support from a cost-benefits analysis.
That commenter stated that this denied the public an opportunity to
evaluate the agency's comparative estimates of costs and benefits
before submitting comments. Advocates argued that the SNPRM did not
fulfill agency's obligation to present the public with the regulatory
alternatives it is considering.
The AIAM stated that it believes there would not be a fair
opportunity for public comment on a two-sided test requirement without
an opportunity of review of revised cost-benefit analysis.
Agency Response
We reject the commenters' arguments that the agency did not provide
a meaningful opportunity for comment. In conjunction with the August
2005 NPRM, the agency's PRIA included an assessment of the 2.5 and 3.0
SWR alternatives. As discussed above, in our January 2008 SNPRM, we
asked for public comment on a number of issues that might affect the
content of the final rule, including possible variations in the
proposed requirements. We also announced the release of the results of
various vehicle tests conducted since the proposal. In the SNPRM, we
noted that we had been carefully analyzing the numerous comments we had
received on the NPRM, as well as the various additional vehicle tests,
including both single-side tests and two-sided tests, conducted since
the NPRM. We invited comments on how the agency should factor the new
information into its decision. We noted that while the NPRM focused on
a specified force equivalent to 2.5 times the unloaded vehicle weight,
the agency could adopt a higher or lower value for the final rule. We
explained, with respect to two-sided vehicle testing, that we believed
there was now sufficient available information for the agency to
consider a two-sided requirement as an alternative to the single-sided
procedure described in the NPRM. We stated that we planned to evaluate
both the single-sided and two-sided testing alternatives for the final
rule and requested comments that would help us reach a decision on that
issue.
While the agency did not provide complete new cost-benefits
analyses to accompany the SNPRM, we included a detailed discussion in
the SNPRM of how estimated impacts of the final rule would be changed
by a number of relevant factors. See 73 FR 5488-5490. These factors
included the pass/fail rate of the vehicle fleet, the impact of the ESC
standard on potential benefits, revised cost and weight estimates, two-
sided testing implications, and other factors.
Thus, in the NPRM and SNPRM, we provided detailed information
concerning the alternatives we were considering and the relevant
issues. We also note that both Public Citizen and Advocates supported a
two-sided test requirement, the alternative we are adopting in today's
rule.
6. Rear Seat Occupants
As a general comment to the NPRM, the Advocates raised a concern
that the quasi-static platen test is not applicable to rear seat
occupants including small children seated in the rear.
Agency Response
We note that the large size of the FMVSS No. 216 platen covers the
rear seat in most vehicles to help ensure protection for rear seat
occupants. We believe that one of the countermeasures that vehicle
manufacturers will use to meet the upgraded roof strength requirements
is strengthening the B-pillars. In terms of possible benefits to small
children, belted occupant injuries sustained due to rollover roof crush
are to the head, neck, and face from contact with roof structures.
Appropriately restrained children are generally not tall enough to
sustain such injuries.
7. New Car Assessment Program (NCAP)
Several commenters suggested that the agency develop a 5-star
rating system concerning roof strength for our NCAP program to provide
the public with information on roof strength and to encourage
manufacturers to improve the roof strength of their vehicles.
[[Page 22377]]
Agency Response
The purpose of this rulemaking is to upgrade our roof strength
standard. The issue of whether roof strength might be addressed in some
way in our NCAP program would be considered separately in the context
of that program.
8. Possible Energy Requirement
We did not propose an energy requirement in the NPRM but indicated
that we would welcome comments on an energy absorption test that had
previously been suggested by SAFE and Syson-Hille and Associates
(Syson).
Agency Response
We received several comments. We appreciate the information
provided in the comments but note that we are not considering
rulemaking in this area.
9. Advanced Restraints
In the NPRM, we presented a summary of our advanced restraints
research and requested comments in this area.
Agency Response
While advanced restraints are not part of this rulemaking, the
agency is continuing research in this area and appreciates the comments
that were provided.
VII. Costs and Benefits
At the time of the NPRM, the agency prepared a PRIA describing the
estimated costs and benefits of the proposal. While the agency did not
provide complete new cost-benefits analyses to accompany the SNPRM, we
included a detailed discussion in the SNPRM of how estimated impacts of
the final rule would be changed by a number of relevant factors. See 73
FR 5488-5490. These factors included the pass/fail rate of the vehicle
fleet, the impact of the ESC standard on potential benefits, revised
cost and weight estimates, two-sided testing implications, and other
factors.
Many commenters addressed the PRIA and the later discussion of
these impacts included in the SNPRM. Among other things, commenters
addressed the target population, the pass/fail rate of the current
fleet, cost and weight impacts, and estimates of benefits.
The agency addresses the comments concerning its analysis of costs
and benefits in detail in the FRIA. In this document, we summarize the
agency's estimates of costs and benefits and discuss the comments
concerning target population and roof crush as a cause of injury.
a. Conclusions of the FRIA
The conclusions of the FRIA can be summarized as follows:
Countermeasures
The agency believes that manufacturers will meet this standard by
strengthening reinforcements in roof pillars, by increasing the gauge
of steel used in roofs, and/or by using higher strength materials. The
agency believes that pressure to improve fuel economy in vehicles,
driven by more stringent Corporate Average Fuel Economy (CAFE)
standards as well as by market forces, together with safety
considerations, will provide a strong incentive for manufacturers to
achieve increased roof strength through use of light weight materials
and stronger roof designs initiated during the redesign cycle. The
agency believes that the phase-in schedule provided in this rule will
allow manufacturers to establish such designs in an efficient manner.
The agency estimates that about 82 percent of all current passenger car
and light truck models with GVWRs less than 2,722 kilograms (6,000
pounds) will need changes to meet the 3.0 SWR requirement, and that 40
percent of vehicles over 2,722 kilograms (6,000 pounds) GVWR will need
changes to meet the 1.5 SWR requirement.
Benefits
The agency estimates that the changes in FMVSS No. 216 will prevent
135 fatalities and 1,065 nonfatal injuries annually.
Costs
The design changes made to comply with higher test load
requirements will add both cost and weight to the vehicle. This will
increase the initial purchase price and will increase lifetime fuel
usage costs.
Taking account of both the costs of design changes and lifetime
fuel usage costs, the agency estimates that compliance with the
upgraded roof strength standard will increase lifetime consumer costs
by $69-$114 per affected vehicle. Redesign costs are expected to
increase affected vehicle prices by an average of about $54. Added
weight is estimated to increase the lifetime cost of fuel usage by $15
to $62 for an average affected vehicle. The range in fuel costs
reflects different discount rate assumptions of 7% and 3%, as well as a
range of assumptions regarding the ability of manufacturers to
incorporate advanced weight saving technology into their redesigned
fleet. Total consumer costs are expected to range from $875 million to
$1.4 billion annually.
Cost Effectiveness and Net Benefits
Cost effectiveness is a measure of the economic investment that is
required to prevent a fatality. The cost effectiveness of this rule was
estimated under both 3% and 7% discount rate assumptions for each
alternative. Nonfatal injuries were translated into fatality
equivalents based on comprehensive valuations that included both
economic impacts and valuations of lost quality of life. To reflect the
present value of benefits that would be experienced over the vehicle's
useful life, the resulting equivalent fatalities were discounted over
the vehicle's life based on annual exposure to crash involvement as
measured by annual miles traveled. The 135 fatalities and 1,065
nonfatal injuries that will be prevented translate into 190 equivalent
fatalities, which are valued at 156 equivalent fatalities under a 3%
discount rate, and 125 equivalent fatalities under a 7% discount rate.
When compared to total costs, the results indicate that the new
standard will cost from $6.1 million to $9.8 million per equivalent
life saved.
Net benefits represent the difference between total costs and the
total monetary value of benefits. DOT's guidance specifies a value of
$5.8 million as the value of a statistical life (VSL), with a range of
uncertainty covering $3.2 million to $8.4 million. The monetary value
of benefits was estimated by assigning a value of $6.1 million to each
equivalent fatality prevented. This value includes the $5.8 million VSL
plus approximately $300,000 of economic savings to represent the
comprehensive societal benefit from preventing a fatality. This means
that the standard would be considered to result in net benefits only if
the cost per equivalent life saved was below $6.1 million.
Net benefits represent the difference between total costs and the
total monetary value of benefits. The monetary value of benefits was
estimated by assigning a value of $6.1 million to each equivalent
fatality prevented. This value consists of a value per statistical life
saved (VSL) of $5.8 million plus $300,000 in economic costs prevented.
For the 3.0/1.5 load requirements of the final rule, the net impact
would range from a net benefit of $6 million to a net loss of $458
million. Using an alternate comprehensive value of $8.7 million (which
consists of a VSL of $8.4 million plus $300,000 in economic savings),
the standard could result in a net benefit of $388 million to a net
loss of $151 million. Using an alternate comprehensive value of $3.5
million (which consists of a VSL of $3.2 million plus $300,000 in
economic savings), the standard could result in a net loss ranging from
$376 million to $824
[[Page 22378]]
million. These impacts are disproportionately influenced by the
relatively large contributions to costs and small contributions to
benefits from vehicles over 6,000 lbs. GVWR. Nearly all alternatives
covering vehicles from 6,001 to 10,000 lbs. GVWR yield net losses
rather than net savings to society.
The following table summarizes the cost and benefits of this final
rule.
Table 2--Cost and Benefit Summary
------------------------------------------------------------------------
------------------------------------------------------------------------
Total Cost............................. $875 to $1,391 million.
Cost per Affected Vehicle.............. $69 to $114.
Benefits............................... 135 fatalities, 1,065 injuries,
190 equivalent fatalities.
Cost per Equivalent Life Saved......... $6.1million to $9.8 million.
Net Benefits........................... $6 million to -$458.
------------------------------------------------------------------------
b. Comments
Target Population
The agency received numerous comments concerning the target
population. CAS and Advocates argued that improving roof strength would
impact ejection and that mitigated ejections should therefore be
included in the agency's benefit calculations. Advocates also argued
that rear seat occupants should be covered by the revised standard.
SAFE argued that roof crush increases the likelihood of glass fracture
and vehicle structure deformation, thereby increasing the possibility
of ejection. It also argued that roof crush reduces the effectiveness
of restraint systems, decreases the effectiveness of rollover air
curtains, and decreases the ability of occupants to be extricated from
the vehicle. The Xprts disagreed with several of NHTSA's target
population restrictions. It stated that ejected occupants, rear seat
occupants, and children under 12 should be included. It also argued
that roof crush can cause thoracic and spinal injuries, and that upper
extremity injuries from ejection through side windows should also be
included. Many of these arguments were repeated in a separate
submission by CFIR signed by one of the Xprts authors. Consumers Union
and Public Citizen also argued that stronger roofs would reduce
ejections and better maintain the performance of other safety features
such as safety belts, air bags, and door locks. Public Citizen also
argued that unbelted occupants would benefit from stronger roofs.
Agency response. We begin our response by noting that Table 1, set
forth earlier in this document, shows a breakdown of the target
population that could potentially benefit from roof crush improvements.
To examine the inclusion of different categories of injuries in the
target population, the agency has conducted several analyses of
ejections in rollovers. The first study was a statistical analysis
examining the relationship between intrusion and ejection. In this
study,\45\ Strashny examined 36 different Probit models examining
belted cases, unbelted cases, complete ejections, all ejections
(including both complete and partial ejection), continuous models,
dichotomous models, adjusted models based on both quarter turns and
roof exposures, as well as unadjusted models. In all, there were 18
models for complete ejections and 18 for all ejections. Strashny found
that there was no significant relationship between the level of
intrusion and the probability of complete ejection in any of the 18
full ejection models. For all ejections, which include partial
ejections, he found some level of significance for 8 of the 18 models,
indicating that a minority of the models found a possibility that some
partial ejections might be influenced by stronger roofs. However, 12 of
the models found no statistically significant relationship between
intrusion and all ejections. We note that partial ejections that meet
the other inclusion criteria are a part of the target population for
this rulemaking.
---------------------------------------------------------------------------
\45\ Strashny, Alexander, ``The Role of Vertical Roof Intrusion
in Predicting Occupant Ejection,'' National Center for Statistics
and Analysis, 2009.
---------------------------------------------------------------------------
The agency then conducted a detailed examination of all fatal
complete ejection cases that were excluded from the target population.
A panel of three NHTSA safety engineers independently examined each
case to determine whether (a) for ejections through open doors, there
was deformation in the door latch area where the root cause could be
directly attributed to roof crush, and (b) for ejections through
windows, if the broken glass through which the occupant was ejected was
directly related to deformation of the roof rather than dynamic crash
impulse loads or side window/door to ground contact. The panel
concluded that there were no cases that met either of these criteria.
Therefore, based on these findings and Strashny's finding of no
statistically significant correlation between intrusion and ejection
probability, all cases of total ejection were excluded from the target
population unless their MAIS level injury occurred inside the vehicle
prior to ejection.
For occupants who were unbelted but not fully ejected, we could not
establish a relationship between roof crush injuries and the magnitude
of roof crush. Strashny analyzed the relationship between intrusion and
injuries to unbelted occupants and found no significant correlation.
This is not unexpected because unbelted occupants essentially become
flying objects inside vehicles as they roll over, and head injuries can
occur at multiple interior locations. Therefore, only belted occupants
are included in the target population.
Regarding the other categories of injuries noted in the comments,
partially ejected occupants were already included in the target
population, and the agency has decided to include rear seat occupants
in the target population. We note that B pillar strength upgrades were
included in all of our finite element countermeasure analyses, and this
support also provides protection for rear occupants. Moreover, vehicle
schematics submitted by both industry and contractors indicate that
some design solutions contemplated for increased roof strength include
not only stronger A- and B-pillars but also a stronger B- to C-pillar
load path to resist platen movement. Such solutions may benefit rear
seat occupants as well as front seat occupants. The agency has also
decided to include belted children in the target population.
Roof Crush as a Cause of Injury
A number of commenters including GM, Ford, Nissan, and SAFE stated
that the statistical correlation Strashny found between roof intrusion
and injury does not establish a causal relationship between roof
deformation and injury. SAFE stated that the studies by both Rains and
Strashny merely suggest that there is a relationship. SAFE stated that
`` * * * when you compare rollover accidents that have significant
roof/pillar deformation with other rollover
[[Page 22379]]
accidents that have very little or no roof/pillar deformation, you are
not comparing similar accidents with respect to roof-to-ground impact
severity. Just the fact that two vehicles are in a rollover with
greater than 2 quarter turns does not mean they are in the same or even
similar impact severities.'' SAFE also noted an earlier study (matched
pair comparison project) in which production and roll bar-equipped
vehicles were tested where the comprehensive forces measured on test
dummies were similar regardless of the vehicle roof crush. Ford stated
that ``The amount of roof deformation is only an indication of the
severity of the impact between the roof and the ground * * *.'' GM
stated that ``Observations of injury occurrence at the end of a
rollover collision reveal nothing regarding the relationship of roof
deformation, roof strength, or roof strength-to-weight ratio injury
causation.'' Nissan stated that deformation and injury severity are
both independently associated with roof impact severity.
Agency Response
The agency agrees that as a general principle, a statistical
correlation does not in itself prove that a causal relationship exists.
However, the Strashny study was designed with a strict focus to only
include injury scenarios where the intruding roof was the injury
source. The study compared cases where there was intrusion to cases
where there was no intrusion and found that as intrusion increases, the
probability of, and severity of injury also increases. The study
controlled for crash severity using quarter turns, which is the best
available metric for rollover severity. Contrary to SAFE's contention,
the study does not compare crashes over 2 quarter turns as a group.
Rather, it compares only crashes of similar severity as defined by each
iterative quarter turn exposure. Thus, a vehicle that experienced 3
quarter turns would only be compared to other vehicles that experienced
3 quarter turns. SAFE's and Ford's arguments appear to imply that any
difference in roof intrusion must be due to a difference in impact
severity rather than roof strength or design, whereas the Strashny
study, by controlling for quarter turns, attempts to minimize
differences due to impact severity. Further, the study included only
belted cases which minimized the impact of ``diving'' as an injury
cause.
There are logical reasons to believe that a collapsing roof that
strikes an occupant's head at the nearly instantaneous impact velocity
experienced when structures deform might cause serious injury. These
types of injuries were documented by Rechnitzer and Lane in a detailed
investigation of 43 rollover crashes.\46\ The agency believes that the
statistically significant relationship between roof intrusion and
belted occupant injury found in the Strashny study indicates not just a
suggestion, but a probability that increasing roof strength reduces
injuries.
---------------------------------------------------------------------------
\46\ Rechnutzer, George and Lane, John, ``Rollover Crash Study,
Vehicle Design and Occupant Injuries'', Monash University, 1994.
---------------------------------------------------------------------------
Regarding the SAFE matched pair comparison project, the agency
notes that the dummy necks used in the tests were not biofidelic. They
are rigid structures that do not allow for the normal bending that
occurs in the human spine. The agency believes that lateral bending
plays an important role in determining the degree of injury sustained
by humans in rollovers, and does not view these results as an adequate
assessment of injury in humans during rollover crashes.
VIII. Rulemaking Analyses and Notices
a. Executive Order 12866 (Regulatory Planning and Review) and DOT
Regulatory Policies and Procedures
The agency has considered the impact of this rulemaking action
under Executive Order 12866 and the Department of Transportation's
regulatory policies and procedures. This rulemaking is economically
significant and was reviewed by the Office of Management and Budget
under E.O. 12866, ``Regulatory Planning and Review.'' The rulemaking
action has also been determined to be significant under the
Department's regulatory policies and procedures. The FRIA fully
discusses the estimated costs and benefits of this rulemaking action.
The costs and benefits are summarized in section VII of this preamble,
supra.
b. Regulatory Flexibility Act
The Regulatory Flexibility Act of 1980, as amended, requires
agencies to evaluate the potential effects of their proposed and final
rules on small businesses, small organizations and small governmental
jurisdictions. I hereby certify that this rule will not have a
significant economic impact on a substantial number of small entities.
Small organizations and small governmental units will not be
significantly affected since the potential cost impacts associated with
this action will not significantly affect the price of new motor
vehicles.
The rule directly affects motor vehicle manufacturers, second stage
or final manufacturers, and alterers. The majority of motor vehicle
manufacturers would not qualify as a small business. There are six
manufacturers of passenger cars that are small businesses.\47\ These
manufacturers, along with manufacturers that do not qualify as a small
business, are already required to comply with the current requirements
of FMVSS No. 216 for vehicles with a GVWR of 2,722 kilograms (6,000
pounds) or less. Improving performance as necessary to meet the
upgraded requirements, and for the requirements for heavier light
vehicles, can be achieved by means including strengthening
reinforcements in roof pillars, by increasing the gauge of steel used
in roofs and by using higher strength materials.
---------------------------------------------------------------------------
\47\ Fisker, Mosler, Panoz, Saleen, Standard Taxi, Tesla.
---------------------------------------------------------------------------
All of these small manufacturers could be affected by the upgraded
requirements. However, the economic impact upon these entities will not
be significant for the following reasons.
(1) Potential cost increases are very small compared to the price
of the vehicles being manufactured and can be passed on to the
consumer.
(2) Some of the vehicles manufactured by these small businesses are
convertibles not subject to this requirement.
(3) The rule provides several years leadtime, and small volume
manufacturers are given the option of waiting until the end of the
phase-in (until September 1, 2015) to meet the upgraded requirements
for lighter vehicles. All manufacturers are given until September 1,
2016 to meet the requirements for the heavier light vehicles.
Most of the intermediate and final stage manufacturers of vehicles
built in two or more stages and alterers have 1,000 or fewer employees.
Some of these companies already are required to comply with the current
requirements of FMVSS No. 216 for vehicles with a GVWR of 2,722
kilograms (6,000 pounds) or less. We have included several provisions
in the final rule to address the special needs of multi-stage
manufacturers and alterers. While the number of these small businesses
potentially affected by this rule is substantial, the economic impact
upon these entities will not be significant for the following reasons:
(1) We are providing a FMVSS No. 220 option for multi-stage
vehicles, except those built on chassis-cab incomplete vehicles, and
for vehicles
[[Page 22380]]
which are changed in certain ways to raise the height of the roof. This
aspect of our rule affords significant economic relief to small
businesses, some of which are already required by States to certify to
the requirements of FMVSS No. 220.
(2) Small businesses using chassis cabs will be in position to take
advantage of ``pass-through certification,'' and therefore are not
expected to incur any additional expenditures.
(3) We are excluding a narrow category of multi-stage vehicles from
FMVSS No. 216 altogether, multi-stage trucks built on incomplete
vehicles other than chassis cabs.
(4) Some of the vehicles manufactured by these small businesses are
convertibles.
(5) Final stage manufacturers and alterers can wait until one year
after the end of the phase-in to meet the new requirements.
Accordingly, there will not be a significant economic impact on
small businesses, small organizations, or small governmental units by
these amendments. For these reasons, the agency has not prepared a
regulatory flexibility analysis.
c. Executive Order 13132 (Federalism)
NHTSA has examined today's 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 rule does not have federalism implications because the rule does
not have ``substantial direct effects on the States, on the
relationship between the national government and the States, or on the
distribution of power and responsibilities among the various levels of
government.''
Further, after careful consideration of the public comments and
further analysis of the issues, NHTSA concludes that no consultation is
needed to discuss the preemptive effect of today's rule. NHTSA's safety
standards can have preemptive effect in at least two ways. First, the
National Traffic and Motor Vehicle Safety Act contains an express
preemption provision: ``When a motor vehicle safety standard is in
effect under this chapter, a State or a political subdivision of a
State may prescribe or continue in effect a standard applicable to the
same aspect of performance of a motor vehicle or motor vehicle
equipment only if the standard is identical to the standard prescribed
under this chapter.'' 49 U.S.C. 30103(b)(1). It is this statutory
command that unavoidably preempts non-identical State legislative and
administrative law, not today's rulemaking, so consultation would be
unnecessary.
Second, the Supreme Court has recognized the possibility of implied
preemption: State requirements imposed on motor vehicle manufacturers,
including sanctions imposed by State tort law, can stand as an obstacle
to the accomplishment and execution of a NHTSA safety standard. When
such a conflict is discerned, the Supremacy Clause of the Constitution
makes the State requirements unenforceable. See Geier v. American Honda
Motor Co., 529 U.S. 861 (2000). For the reasons explained below, the
agency has reconsidered the tentative position presented in the NPRM
and does not currently foresee any potential State tort requirements
that might conflict with today's final rule.
In the NPRM, NHTSA considered the objectives of the proposed roof
crush resistance upgrade in the context of the agency's overall
rollover plan and addressed whether there might be specific conflicts
between the standard and anticipated State tort law. The agency opined
on the possibility that certain State tort law actions might conflict
with an improved Federal roof crush resistance standard and that those
conflicts could result in those actions being determined by a court to
be impliedly preempted. It presented the following tentative
conclusions:
Overall, safety would best be promoted by the careful
balance it had struck in the proposal among a variety of considerations
and objectives regarding rollover safety.
The proposal to upgrade roof crush resistance was a part
of a comprehensive plan for reducing the serious risk of rollover
crashes and the risk of death and serious injury in those crashes. The
objective of the proposal was to increase the requirement for roof
crush resistance only to the extent that it can be done without
creating too much risk of negatively affecting vehicle dynamics and
rollover propensity. Excessively increasing current roof crush
resistance requirements could lead vehicle manufacturers to add weight
to vehicle roof and pillars, thereby raising the vehicle center of
gravity (CG) and increasing rollover propensity.
Some methods of improving roof crush resistance are
costlier than others and the resources diverted to increasing roof
strength using one of the costlier methods could delay or even prevent
vehicle manufacturers from equipping their vehicles with advanced
vehicle technologies for reducing rollovers.
Either a broad State performance requirement for levels of
roof crush resistance greater than those proposed or a narrower
requirement mandating that increased roof strength be achieved by a
particular specified means, could frustrate the agency's objectives by
upsetting the balance between efforts to increase roof strength and
reduce rollover propensity.
Based on this conflict analysis, if the proposal were
adopted as a final rule, all conflicting State common law requirements,
including rules of tort law, would be subject to being found to be
impliedly preempted.
1. Public Comments About NHTSA's Tentative Views on Conflict and
Preemption
Vehicle manufacturers and one legal advocacy organization strongly
supported the view that an upgraded roof crush standard would conflict
with and therefore impliedly preempt State rules of tort law imposing
more stringent requirements than the one ultimately adopted by NHTSA.
Consumer advocacy groups, members of Congress and State officials,
trial lawyers, consultants and members of academia, and private
individuals strongly opposed our view that there could be conflict. The
opposing letters from State officials included one signed by 27 State
Attorneys General and the National Conference of State Legislatures.
A summary of the primary arguments of the commenters on each side
follows:
A. Primary Arguments for the Existence of Conflict
There is a limit to the increases in roof crush resistance
or stiffening that can practicably be achieved across the fleet without
introducing unacceptable risk of undesirable effects, such as increases
in the height of the center of gravity of the vehicle or diverting
resources away from other promising advanced vehicle technologies for
reducing rollovers.
Small additions of weight and small changes in center of
gravity height will, based on NHTSA's analysis presented in Appendix A
of the PRIA, have large consequences on the level of rollover risk and
risk of associated fatalities and injuries. Moreover, the weight
impacts of meeting requirements at different SWR levels are greater
than estimated by the agency in the PRIA.
There is a conflict between the agency's comprehensive
rollover policy and some state common law rules related to roof
strength. Any state
[[Page 22381]]
common law rule that would purport to impose a duty to design vehicles'
roofs to meet a more stringent strength requirement has the potential,
as a practical matter, to result in a reduction in vehicle stability
(as measured by average SSF), at least for some vehicle models in the
fleet. Such a result would undercut NHTSA's overall rollover mitigation
policy that has been developed to balance the competing goals of
preventing rollover crashes in the first place and of reducing the risk
of injury when such crashes nevertheless occur.
The creation of a patchwork of different State roof crush
resistance requirements across the country would not contribute toward
achievement of an appropriate balancing of roof strength and rollover
propensity.
Being required to devote resources to increasing roof
strength using one of the costlier methods could delay or even prevent
manufacturers from installing advanced vehicle technologies for
reducing rollovers.
The agency should also be concerned about another
potential safety conflict, in the area of vehicle compatibility, as the
addition of weight increases the chances of vehicle mass mismatch in a
collision.
B. Primary Arguments Against the Existence of Conflict
NHTSA's claims that a more stringent standard could result
in increased vehicle weight and decreased stability are not supported
by the record.
Manufacturers can strengthen roofs by a variety of means
without significantly increasing weight, and advanced steels and other
lightweight materials can be used to strengthen roofs without a weight
increase.
NHTSA's data show that increases in roof structural
strength will not have a physically measurable influence on CG height.
Production of vehicles that exceed the NHTSA standard would enhance the
safety objectives of that standard.
NHTSA did not provide any examples of vehicles with
elevated rollover risk due to weight added to the roof. An examination
of the vehicle fleet, including the Volvo XC90 and vehicles with high
SWRs tested after publication of the NPRM, shows that the agency's
concerns are unfounded.
The agency's statement that resources used to increase
roof strength could divert resources away from other promising advanced
vehicle technologies for reducing rollovers is unsupported and
speculative. Manufacturers can do both.
Given the agency's New Car Assessment Program,
manufacturers would improve roof strength using design changes that
avoid a lower star rating.
The tort system would provide the best incentive for
manufacturers to make design decisions that will not increase rollover
propensity.
The premise behind NHTSA's analysis is incorrect because
plaintiffs alleging a design defect must prove that the alternative
design would not have created more injuries in other accidents.
The Geier case does not support preemption as the
situation it addressed involved two key factors that are not present
here: Consumer resistance to air bags and the need to foster innovation
in passive restraint technology. Preemption in this case is
inconsistent with the statutory savings clause.
The agency's statement is overbroad in being applied to
all vehicles covered by the standard, without regard to their
individual design characteristics or their manufacturers' ability to
exceed the standard without negatively affecting vehicle dynamics and
rollover propensity.
2. Preemption, Geier and the National Traffic and Motor Vehicle Safety
Act
In Geier, 529 U.S. 861 (2000), the Supreme Court specifically
addressed the possible preemptive effect of the National Traffic and
Motor Vehicle Safety Act, taken together with Federal motor vehicle
safety standards issued under that Act, on common law tort claims. The
issue before the court was whether the Safety Act, together with FMVSS
No. 208, preempted a lawsuit claiming a 1987 car was defective for
lacking a driver air bag. When the car was manufactured, FMVSS No. 208
had required manufacturers to equip some but not all of their vehicles
with passive restraints.
The conclusions of Geier can be summarized as follows:
The Safety Act's provision expressly preempting state
``standards'' does not preempt common law tort claims. The issue of
whether the term ``standards'' includes tort law actions is resolved by
another provision in the Safety Act--the ``savings'' clause. That
provision states that ``(c)ompliance with'' a Federal safety standard
``does not exempt any person from any liability under common law.''
The savings clause preserves those tort actions that seek
to establish greater safety than the minimum safety achieved by a
Federal regulation intended to provide a floor.
The savings clause does not bar the working of conflict
preemption principles. Nor does the preemption provision, the saving
provision, or both read together, create some kind of ``special
burden'' beyond that inherent in ordinary preemption principles that
would specially disfavor pre-emption. The two provisions, read
together, reflect a neutral policy, not a specially favorable or
unfavorable policy, toward the application of ordinary conflict
preemption principles.
The preemption provision itself reflects a desire to
subject the industry to a single, uniform set of Federal safety
standards. On the other hand, the savings clause reflects a
congressional determination that occasional nonuniformity is a small
price to pay for a system in which juries not only create, but also
enforce, safety standards, while simultaneously providing necessary
compensation to victims. Nothing in any natural reading of the two
provisions favors one set of policies over the other where a jury-
imposed safety standard actually conflicts with a Federal safety
standard.
A court should not find preemption too readily in the
absence of clear evidence of a conflict.
The common-law ``no airbag'' action before the Court was
preempted because it actually conflicted with FMVSS No. 208. That
standard sought a gradually developing mix of alternative passive
restraint devices for safety-related reasons. The rule of state tort
law sought by the petitioner would have required manufacturers of all
similar cars to install air bags rather than other passive restraint
systems, thereby presenting an obstacle to the variety and mix of
devices that the Federal regulation sought.
3. Agency Testing and Discussion
In the NPRM, we noted the well-established physical relationship
between center of gravity (CG) and rollover propensity. It is reflected
in our NCAP ratings program. All other things being equal, increasing
the CG of a vehicle increases its rollover propensity.
We also posited a second relationship, one between CG and SWR. We
identified a hypothetical fleet impact in which the weight and center
of gravity effects of complying with a 2.5 SWR requirement could result
in additional rollovers and added fatalities. This analysis was
presented in Appendix A of the PRIA. As discussed in that document,
there were various uncertainties and caveats associated with the
analysis. The agency believed that manufacturers would take steps to
avoid negative effects on rollover propensity.
[[Page 22382]]
We note that NHTSA has updated that analysis for the FRIA,
addressing 2.5, 3.0 and 3.5 SWR alternatives. As discussed in the FRIA,
the agency believes that, for the alternatives analyzed, manufacturers
could and would take steps sufficient to avoid negative effects on
rollover propensity if sufficient leadtime is provided for them to do
so.
As noted earlier, NHTSA has done testing of vehicles measuring roof
crush resistance performance, much of it completed after publication of
the NPRM. Twelve of the vehicles tested by NHTSA after the NPRM had
(one-sided) SWRs of 3.9 or higher. As part of our fleet testing, NHTSA
has also tested three paired vehicles \48\ for which manufacturers
significantly increased SWR as part of redesigning the vehicle. In each
case, SWR was increased without increasing rollover propensity as
measured by SSF. In two of the cases, CG stayed about the same (it did
not increase); in the other, CG did increase but other changes (track
width) offset the negative effect of higher CG.
---------------------------------------------------------------------------
\48\ 2002 and 2007 Toyota Camry; 2003 and 2007 Toyota Tacoma;
2004 and 2008 Honda Accord.
---------------------------------------------------------------------------
4. Agency Views About Conflict Preemption
As discussed above, the Supreme Court has recognized the
possibility of implied preemption: State requirements imposed on motor
vehicle manufacturers, including sanctions imposed by State tort law,
can stand as obstacles to the accomplishment and execution of a NHTSA
safety standard. When such a conflict is discerned, the Supremacy
Clause of the Constitution makes the State requirements unenforceable.
Since implied preemption turns upon the existence of an actual
conflict, we, as the agency charged with effectively carrying out the
Act and possessing substantial technical expertise regarding the
subject matter and purposes of the Federal motor vehicle safety
standards and the Vehicle Safety Act, address whether conflicts exist
in our rulemaking notices. In most rulemakings, we do not foresee the
possibility of there being any state requirements that would create
conflicts.
Following the principles set forth in Geier, we are providing our
views concerning the issue of whether conflicts may exist in connection
with the requirements being adopted in this final rule. We believe that
this is appropriately responsive to statements by several Supreme Court
justices encouraging agencies to consider and discuss the possible
preemptive effects of their rulemakings.\49\
---------------------------------------------------------------------------
\49\ See, e.g., Hillsborough County v. Automated Medical
Laboratories, Inc., 471 U.S. 707, 718 (1985); Medtronic, Inc., v.
Lohr, 518 U.S. 470, 506 (1996) (Justice Breyer, in concurrence); and
Geier v. American Honda Motor Co., 529 U.S. 861, 908 (2000) (Justice
Stevens, in dissent).
---------------------------------------------------------------------------
After considering the public comments on the proposal and
considering today's final rule, NHTSA has reconsidered the tentative
position presented in the NPRM and do not currently foresee any
potential State tort requirements that might conflict with today's
final rule. Without any conflict, there could not be any implied
preemption.
In the NPRM, we stated that it was our tentative judgment that
safety would be best promoted by the balance we had struck in the
proposal among a variety of considerations and objectives regarding
rollover safety. We explained that it was the objective of the proposal
to increase the requirement for roof crush resistance only to the
extent that it could be done without creating too much risk of
negatively affecting vehicle dynamics and rollover propensity. We
expressed concern that excessively increasing current roof crush
resistance requirements could lead vehicle manufacturers to add weight
to vehicle roof and pillars, thereby raising the vehicle center of
gravity (CG) and increasing rollover propensity. As part of our
tentative position, we indicated in the NPRM that a broad State
performance requirement for more stringent levels of roof crush
resistance could frustrate the agency's objectives by upsetting the
balance between efforts to increase roof strength and reduce rollover
propensity.
Based on the record for this final rule, we cannot identify a level
of stringency of roof crush resistance above which tort laws would
conflict. For example, we cannot say that any particular levels of roof
crush resistance above those required by today's rule would likely
result in unacceptable levels of rollover resistance. Similarly, we
cannot identify any level of roof crush resistance above which it would
be expected that net safety benefits would diminish.
As discussed earlier, there are ways of improving roof strength
that avoid or minimize adding weight high in the vehicle (e.g., use of
advanced lightweight materials), and there are other design
characteristics that can be used to offset or eliminate any potential
change in rollover stability due to increased CG (e.g., increased track
width). Moreover, during our fleet testing, we observed three paired
vehicles for which manufacturers significantly increased SWR as part of
redesigning the vehicle, without increasing rollover propensity as
measured by SSF. Finally, while there would be increasing technical
challenges for vehicle manufacturers to meet successively higher SWR
levels above the alternatives we analyzed, those challenges would vary
considerably depending on the nature of the vehicle, e.g., weight,
size, geometry, etc., making it essentially impossible for NHTSA to
define a level of roof crush stringency likely to cause a conflict with
our rollover resistance objectives.
As to another concern we identified in the NPRM, the possibility
that some kinds of State tort laws requiring improved roof crush
resistance might cause a diversion of resources away from manufacturer
efforts to use advanced technologies to reduce rollovers, we have
concluded that it is not possible to identify how such resources would
otherwise have been used. Specifically, there is not a basis to
conclude that such resources would otherwise have been used for
improving rollover resistance or improving safety. Therefore, we
believe that such tort laws do not create a conflict on these grounds.
Finally, as noted earlier, vehicle manufacturers suggested that we
consider a potential policy conflict in the area of vehicle
compatibility. They stated that the addition of weight would increase
the chances of vehicle mass mismatch in a collision. However, mass
mismatch is only one key aspect of vehicle-to-vehicle crash
compatibility, particularly in frontal crashes. Vehicle stiffness and
geometric alignment are also important factors in vehicle
compatibility. While it is hypothetically possible that some kinds of
tort laws on roof strength could contribute toward greater differential
in weight between some vehicles, e.g., if they resulted in
manufacturers adding significant weight to heavier vehicles, we believe
it is not possible to define any level of stringency of roof crush
resistance above which tort laws would create a conflict with our
vehicle compatibility objectives. We note that in redesigning vehicles
in ways that improve roof strength and also minimize impacts on vehicle
mass, manufacturers have many design options to avoid or minimize
adding weight (e.g., use of advanced light materials in various parts
of the vehicle, including ones other than those related to the roof).
There may also be ways of offsetting any possible incremental change in
fleet compatibility due to increased weight mismatch that might occur
with vehicle geometric and/or stiffness design
[[Page 22383]]
modifications. We note that the vehicle manufacturers did not provide
technical analysis addressing the latter issue.
Therefore, although under the principles enunciated in Geier it is
possible that a rule of State tort law could conflict with a NHTSA
safety standard if it created an obstacle to the accomplishment and
execution of that standard, we do not currently foresee the likelihood
of any such tort requirements and do not have a basis for concluding
that any particular levels of stringency would create such a conflict.
d. Unfunded Mandates Reform Act
The Unfunded Mandates Reform Act of 1995 (UMRA) 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 annually for inflation, with base year
of 1995). These effects are discussed earlier in this preamble and in
the FRIA. UMRA also requires an agency issuing a final rule subject to
the Act to select the ``least costly, most cost-effective or least
burdensome alternative that achieves the objectives of the rule.''
The preamble and the FRIA identify and consider a number of
alternatives, concerning factors such as single- or two-sided test
requirements, different SWR levels, and phase-in schedule. Alternatives
considered by and rejected by us would not fully achieve the objectives
of the alternative preferred by NHTSA (a reasonable balance between the
benefits and costs). The agency believes that it has selected the most
cost-effective alternative that achieves the objectives of the
rulemaking.
e. National Environmental Policy Act
NHTSA has analyzed this final rule for the purposes of the National
Environmental Policy Act. The agency has determined that implementation
of this action will not have any significant impact on the quality of
the human environment.
f. Executive Order 12778 (Civil Justice Reform)
With respect to the review of the promulgation of a new regulation,
section 3(b) of Executive Order 12988, ``Civil Justice Reform'' (61 FR
4729, February 7, 1996) requires that Executive agencies make every
reasonable effort to ensure that the regulation: (1) Clearly specifies
the preemptive effect; (2) clearly specifies the effect on existing
Federal law or regulation; (3) provides a clear legal standard for
affected conduct, while promoting simplification and burden reduction;
(4) clearly specifies the retroactive effect, if any; (5) adequately
defines key terms; and (6) addresses other important issues affecting
clarity and general draftsmanship under any guidelines issued by the
Attorney General. This document is consistent with that requirement.
Pursuant to this Order, NHTSA notes as follows. The preemptive
effect of this rule is discussed above. NHTSA notes further that there
is no requirement that individuals submit a petition for
reconsideration or pursue other administrative proceeding before they
may file suit in court.
g. Plain Language
Executive Order 12866 requires each agency to write all rules in
plain language. Application of the principles of plain language
includes consideration of the following questions:
Have we organized the material to suit the public's needs?
Are the requirements in the rule clearly stated?
Does the rule contain technical language or jargon that
isn't clear?
Would a different format (grouping and order of sections,
use of headings, paragraphing) make the rule easier to understand?
Would more (but shorter) sections be better?
Could we improve clarity by adding tables, lists, or
diagrams?
What else could we do to make the rule easier to
understand?
If you have any responses to these questions, please write to us
with your views.
h. Paperwork Reduction Act (PRA)
Under the PRA of 1995, 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. The final rule contains a
collection of information because of the proposed phase-in reporting
requirements. There is no burden to the general public.
The collection of information requires manufacturers of passenger
cars and multipurpose passenger vehicles, trucks and buses with a GVWR
of 2,722 kilograms (6,000 pounds) or less to annually submit a report,
and maintain records related to the report, concerning the number of
such vehicles that meet the upgraded roof strength requirements. The
phase-in will cover three years. The purpose of the reporting and
recordkeeping requirements is to assist the agency in determining
whether a manufacturer of vehicles has complied with the requirements
during the phase-in period.
We will submit a request for OMB clearance of the collection of
information required under today's final rule in time to obtain
clearance prior to the beginning of the phase-in at the beginning of
September 2012.
These requirements and our estimates of the burden to vehicle
manufacturers are as follows:
NHTSA estimates that there are 21 manufacturers of passenger cars,
multipurpose passenger vehicles, trucks, and buses with a GVWR of 2,722
kilograms (6,000 pounds) or less;
NHTSA estimates that the total annual reporting and recordkeeping
burden resulting from the collection of information is 1,260 hours;
NHTSA estimates that the total annual cost burden, in U.S. dollars,
will be $0. No additional resources will be expended by vehicle
manufacturers to gather annual production information because they
already compile this data for their own use.
A Federal Register document must provide a 60-day comment period
concerning the collection of information. The Office of Management and
Budget (OMB) promulgated regulations describing what must be included
in such a document. Under OMB's regulations (5 CFR 320.8(d)), agencies
must ask for public comment on the following:
(1) Whether the collection of information is necessary for the
proper performance of the functions of the agency, including whether
the information will have practical utility;
(2) The accuracy of the agency's estimate of the burden of the
proposed collection of information, including the validity of the
methodology and assumptions used;
(3) How to enhance the quality, utility, and clarity of the
information to be collected; and,
(4) How to minimize the burden of the collection of information on
those who are to respond, including the use of appropriate automated,
electronic, mechanical, or other technological collection techniques or
other forms of information technology, e.g., permitting electronic
submission of responses.
i. National Technology Transfer and Advancement Act
Under the National Technology Transfer and Advancement Act of 1995
(NTTAA) (Pub. L. 104-113),
All Federal agencies and departments shall use technical standards
that are developed or adopted by voluntary consensus standards
[[Page 22384]]
bodies, using such technical standards as a means to carry out
policy objectives or activities determined by the agencies and
departments.
Voluntary consensus standards are technical standards (e.g.,
materials specifications, test methods, sampling procedures, and
business practices) that are developed or adopted by voluntary
consensus standards bodies, such as 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.
We are incorporating the voluntary consensus standard SAE Standard
J826 ``Devices for Use in Defining and Measuring Vehicle Seating
Accommodation,'' SAE J826 (rev. July 1995) into the requirements of
FMVSS No. 216a as part of this rulemaking. As discussed in the NPRM, we
evaluated the SAE inverted drop testing procedure, but decided against
proposing it.
List of Subjects
49 CFR Part 571
Imports, Incorporation by reference, Motor vehicle safety,
Reporting and recordkeeping requirements, Tires.
49 CFR Part 585
Motor vehicle safety, Reporting and recordkeeping requirements.
0
In consideration of the foregoing, NHTSA amends 49 CFR Chapter V as set
forth below.
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
0
1. The authority citation for part 571 of title 49 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.50.
0
2. Section 571.216 is amended by revising the section heading and S3 to
read as follows:
Sec. 571.216 Standard No. 216; Roof crush resistance; Applicable
unless a vehicle is certified to Sec. 571.216a.
* * * * *
S3. Application.
(a) This standard applies to passenger cars, and to multipurpose
passenger vehicles, trucks and buses with a GVWR of 2,722 kilograms
(6,000 pounds) or less. However, it does not apply to--
(a) School buses;
(b) Vehicles that conform to the rollover test requirements (S5.3)
of Standard No. 208 (Sec. 571.208) by means that require no action by
vehicle occupants;
(c) Convertibles, except for optional compliance with the standard
as an alternative to the rollover test requirements in S5.3 of Standard
No. 208; or
(d) Vehicles certified to comply with Sec. 571.216a.
* * * * *
0
3. Section 571.216a is added to read as follows:
Sec. 571.216a Standard No. 216a; Roof crush resistance; Upgraded
standard.
S1. Scope. This standard establishes strength requirements for the
passenger compartment roof.
S2. Purpose. The purpose of this standard is to reduce deaths and
injuries due to the crushing of the roof into the occupant compartment
in rollover crashes.
S3. Application, incorporation by reference, and selection of
compliance options.
S3.1 Application.
(a) This standard applies to passenger cars, and to multipurpose
passenger vehicles, trucks and buses with a GVWR of 4,536 kilograms
(10,000 pounds) or less, according to the implementation schedule
specified in S8 and S9 of this section. However, it does not apply to--
(1) School buses;
(2) Vehicles that conform to the rollover test requirements (S5.3)
of Standard No. 208 (Sec. 571.208) by means that require no action by
vehicle occupants;
(3) Convertibles, except for optional compliance with the standard
as an alternative to the rollover test requirement (S5.3) of Standard
No. 208; or
(4) Trucks built in two or more stages with a GVWR greater than
2,722 kilograms (6,000 pounds) not built using a chassis cab.
(b) At the option of the manufacturer, vehicles within either of
the following categories may comply with the roof crush requirements
(S4) of Standard No. 220 (Sec. 571.220) instead of the requirements of
this standard:
(1) Vehicles built in two or more stages, other than vehicles built
using a chassis cab;
(2) Vehicles with a GVWR greater than 2,722 kilograms (6,000
pounds) that have an altered roof as defined by S4 of this section.
(c) Manufacturers may comply with the standard in this Sec.
571.216a as an alternative to Sec. 571.216.
S3.2 Incorporation by reference. Society of Automotive Engineers
(SAE) Standard J826 ``Devices for Use in Defining and Measuring Vehicle
Seating Accommodation,'' SAE J826 (rev. July 1995) is incorporated by
reference in S7.2 of this section. The Director of the Federal Register
has approved the incorporation by reference of this material in
accordance with 5 U.S.C. 552(a) and 1 CFR part 51. A copy of SAE J826
(rev. Jul 95) may be obtained from SAE at the Society of Automotive
Engineers, Inc., 400 Commonwealth Drive, Warrendale, PA 15096. Phone:
1-724-776-4841; Web: http://www.sae.org. A copy of SAE J826 (July 1995)
may be inspected at NHTSA's Technical Information Services, 1200 New
Jersey Avenue, Washington, DC 20590, or at the National Archives and
Records Administration (NARA). For information on the availability of
this material at NARA, call 202-741-6030, or go to: http://www.archives.gov/federal_register/code_of_federal_regulations/ibr_locations.html.
S3.3 Selection of compliance option. Where manufacturer options are
specified, the manufacturer shall select the option by the time it
certifies the vehicle and may not thereafter select a different option
for the vehicle. Each manufacturer shall, upon the request from the
National Highway Traffic Safety Administration, provide information
regarding which of the compliance options it selected for a particular
vehicle or make/model.
S4. Definitions.
Altered roof means the replacement roof on a motor vehicle whose
original roof has been removed, in part or in total, and replaced by a
roof that is higher than the original roof. The replacement roof on a
motor vehicle whose original roof has been replaced, in whole or in
part, by a roof that consists of glazing materials, such as those in T-
tops and sunroofs, and is located at the level of the original roof, is
not considered to be an altered roof.
Convertible means a vehicle whose A-pillars are not joined with the
B-pillars (or rearmost pillars) by a fixed, rigid structural member.
S5. Requirements.
S5.1 When the test device described in S6 is used to apply a force
to a vehicle's roof in accordance with S7, first to one side of the
roof and then to the other side of the roof:
(a) The lower surface of the test device must not move more than
127 millimeters, and
(b) No load greater than 222 Newtons (50 pounds) may be applied to
the head form specified in S5.2 of 49 CFR 571.201 located at the head
position of a 50th percentile adult male in accordance with S7.2 of
this section.
[[Page 22385]]
S5.2 The maximum applied force to the vehicle's roof in Newtons is:
(a) For vehicles with a GVWR of 2,722 kilograms (6,000 pounds) or
less, any value up to and including 3.0 times the unloaded vehicle
weight of the vehicle, measured in kilograms and multiplied by 9.8, and
(b) For vehicles with a GVWR greater than 2,722 kilograms (6,000
pounds), any value up to and including 1.5 times the unloaded vehicle
weight of the vehicle, measured in kilograms and multiplied by 9.8.
S6. Test device. The test device is a rigid unyielding block whose
lower surface is a flat rectangle measuring 762 millimeters by 1,829
millimeters.
S7. Test procedure. Each vehicle must be capable of meeting the
requirements of S5 when tested in accordance with the procedure in S7.1
through S7.6.
S7.1 Support the vehicle off its suspension and rigidly secure the
sills and the chassis frame (when applicable) of the vehicle on a rigid
horizontal surface(s) at a longitudinal attitude of 0 degrees 0.5 degrees. Measure the longitudinal vehicle attitude along
both the driver and passenger sill. Determine the lateral vehicle
attitude by measuring the vertical distance between a level surface and
a standard reference point on the bottom of the driver and passenger
side sills. The difference between the vertical distance measured on
the driver side and the passenger side sills is not more than 10 mm. Close all windows, close and lock all doors, and close
and secure any moveable roof panel, moveable shade, or removable roof
structure in place over the occupant compartment. Remove roof racks or
other non-structural components. For a vehicle built on a chassis-cab
incomplete vehicle that has some portion of the added body structure
above the height of the incomplete vehicle, remove the entire added
body structure prior to testing (the vehicle's unloaded vehicle weight
as specified in S5 includes the weight of the added body structure).
S7.2 Adjust the seats in accordance with S8.3 of 49 CFR 571.214.
Position the top center of the head form specified in S5.2 of 49 CFR
571.201 at the location of the top center of the Head Restraint
Measurement Device (HRMD) specified in 49 CFR 571.202a, in the front
outboard designated seating position on the side of the vehicle being
tested as follows:
(a) Position the three dimensional manikin specified in Society of
Automotive Engineers (SAE) Surface Vehicle Standard J826, revised July
1995, ``Devices for Use in Defining and Measuring Vehicle Seating
Accommodation,'' (incorporated by reference, see paragraph S3.2), in
accordance to the seating procedure specified in that document, except
that the length of the lower leg and thigh segments of the H-point
machine are adjusted to 414 and 401 millimeters, respectively, instead
of the 50th percentile values specified in Table 1 of SAE J826 (July
1995).
(b) Remove four torso weights from the three-dimensional manikin
specified in SAE J826 (July 1995) (two from the left side and two from
the right side), replace with two HRMD torso weights (one on each
side), and attach and level the HRMD head form.
(c) Mark the location of the top center of the HRMD in three
dimensional space to locate the top center of the head form specified
in S5.2 of 49 CFR 571.201.
S7.3 Orient the test device as shown in Figure 1 of this section,
so that--
(a) Its longitudinal axis is at a forward angle (in side view) of 5
degrees ( 0.5 degrees) below the horizontal, and is
parallel to the vertical plane through the vehicle's longitudinal
centerline;
(b) Its transverse axis is at an outboard angle, in the front view
projection, of 25 degrees below the horizontal ( 0.5
degrees).
S7.4 Maintaining the orientation specified in S7.3 of this
section--
(a) Lower the test device until it initially makes contact with the
roof of the vehicle.
(b) Position the test device so that--
(1) The longitudinal centerline on its lower surface is within 10
mm of the initial point of contact, or on the center of the initial
contact area, with the roof; and
(2) The midpoint of the forward edge of the lower surface of the
test device is within 10 mm of the transverse vertical plane 254 mm
forward of the forwardmost point on the exterior surface of the roof,
including windshield trim, that lies in the longitudinal vertical plane
passing through the vehicle's longitudinal centerline.
S7.5 Apply force so that the test device moves in a downward
direction perpendicular to the lower surface of the test device at a
rate of not more than 13 millimeters per second until reaching the
force level specified in S5. Guide the test device so that throughout
the test it moves, without rotation, in a straight line with its lower
surface oriented as specified in S7.3(a) and S7.3(b). Complete the test
within 120 seconds.
S7.6 Repeat the test on the other side of the vehicle.
S8. Phase-in schedule for vehicles with a GVWR of 2,722 kilograms
(6,000 pounds) or less.
S8.1 Vehicles manufactured on or after September 1, 2012, and
before September 1, 2013. For vehicles manufactured on or after
September 1, 2012, and before September 1, 2013, the number of vehicles
complying with this standard must not be less than 25 percent of:
(a) The manufacturer's average annual production of vehicles
manufactured on or after September 1, 2009, and before September 1,
2012; or
(b) The manufacturer's production on or after September 1, 2012,
and before September 1, 2013.
S8.2 Vehicles manufactured on or after September 1, 2013, and
before September 1, 2014. For vehicles manufactured on or after
September 1, 2013, and before September 1, 2014, the number of vehicles
complying with this standard must not be less than 50 percent of:
(a) The manufacturer's average annual production of vehicles
manufactured on or after September 1, 2010, and before September 1,
2013; or
(b) The manufacturer's production on or after September 1, 2013,
and before September 1, 2014.
S8.3 Vehicles manufactured on or after September 1, 2014, and
before September 1, 2015. For vehicles manufactured on or after
September 1, 2014, and before September 1, 2015, the number of vehicles
complying with this standard must not be less than 75 percent of:
(a) The manufacturer's average annual production of vehicles
manufactured on or after September 1, 2011, and before September 1,
2014; or
(b) The manufacturer's production on or after September 1, 2014,
and before September 1, 2015.
S8.4 Vehicles manufactured on or after September 1, 2015. Except as
provided in S8.8, each vehicle manufactured on or after September 1,
2015 must comply with this standard.
S8.5 Calculation of complying vehicles.
(a) For purpose of complying with S8.1, a manufacturer may count a
vehicle if it is certified as complying with this standard and is
manufactured on or after September 1, 2012, but before September 1,
2013.
(b) For purposes of complying with S8.2, a manufacturer may count a
vehicle if it:
(1) Is certified as complying with this standard and is
manufactured on or after September 1, 2012, but before September 1,
2014; and
(2) Is not counted toward compliance with S8.1.
[[Page 22386]]
(c) For purposes of complying with S8.3, a manufacturer may count a
vehicle if it:
(1) Is certified as complying with this standard and is
manufactured on or after September 1, 2012, but before September 1,
2015; and
(2) Is not counted toward compliance with S8.1 or S8.2.
S8.6 Vehicles produced by more than one manufacturer.
S8.6.1 For the purpose of calculating average annual production of
vehicles for each manufacturer and the number of vehicles manufactured
by each manufacturer under S8.1 through S8.3, a vehicle produced by
more than one manufacturer must be attributed to a single manufacturer
as follows, subject to S8.6.2:
(a) A vehicle that is imported must be attributed to the importer.
(b) A vehicle manufactured in the United States by more than one
manufacturer, one of which also markets the vehicle, must be attributed
to the manufacturer that markets the vehicle.
S8.6.2 A vehicle produced by more than one manufacturer must be
attributed to any one of the vehicle's manufacturers specified by an
express written contract, reported to the National Highway Traffic
Safety Administration under 49 CFR Part 585, between the manufacturer
so specified and the manufacturer to which the vehicle would otherwise
be attributed under S8.6.1.
S8.7 Small volume manufacturers.
Vehicles manufactured during any of the three years of the
September 1, 2012 through August 31, 2015 phase-in by a manufacturer
that produces fewer than 5,000 vehicles for sale in the United States
during that year are not subject to the requirements of S8.1, S8.2, and
S8.3.
S8.8 Final-stage manufacturers and alterers.
Vehicles that are manufactured in two or more stages or that are
altered (within the meaning of 49 CFR 567.7) after having previously
been certified in accordance with Part 567 of this chapter are not
subject to the requirements of S8.1 through S8.3. Instead, all vehicles
produced by these manufacturers on or after September 1, 2016 must
comply with this standard.
S9 Vehicles with a GVWR above 2,722 kilograms (6,000 pounds).
(a) Except as provided in S9(b), each vehicle manufactured on or
after September 1, 2016 must comply with this standard.
(b) Vehicles that are manufactured in two or more stages or that
are altered (within the meaning of 49 CFR 567.7) after having
previously been certified in accordance with Part 567 of this chapter
are not subject to the requirements of S8.1 through S8.3. Instead, all
vehicles produced by these manufacturers on or after September 1, 2017
must comply with this standard.
BILLING CODE P
[[Page 22387]]
[GRAPHIC] [TIFF OMITTED] TR12MY09.063
0
6. The authority citation for Part 585 continues to read as follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegation of authority at 49 CFR 1.50.
PART 585--[AMENDED]
0
7. Part 585 is amended by adding Subpart L to read as follows:
[[Page 22388]]
Subpart L--Roof Crush Resistance Phase-in Reporting Requirements
Sec.
585.111 Scope.
585.112 Purpose.
585.113 Applicability.
585.114 Definitions.
585.115 Response to inquiries.
585.116 Reporting requirements.
585.117 Records.
Subpart L--Roof Crush Resistance Phase-in Reporting Requirements
Sec. 585.111 Scope.
This subpart establishes requirements for manufacturers of
passenger cars, multipurpose passenger vehicles, trucks, and buses with
a gross vehicle weight rating of 2,722 kilograms (6,000 pounds) or less
to submit a report, and maintain records related to the report,
concerning the number of such vehicles that meet the requirements of
Standard No. 216a; Roof crush resistance; Upgraded standard (49 CFR
571.216a).
Sec. 585.112 Purpose.
The purpose of these reporting requirements is to assist the
National Highway Traffic Safety Administration in determining whether a
manufacturer has complied with Standard No. 216a (49 CFR 571.216a).
Sec. 585.113 Applicability.
This subpart applies to manufacturers of passenger cars,
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating of 2,722 kilograms (6,000 pounds) or less. However, this
subpart does not apply to manufacturers whose production consists
exclusively of vehicles manufactured in two or more stages, and
vehicles that are altered after previously having been certified in
accordance with part 567 of this chapter. In addition, this subpart
does not apply to manufacturers whose production of motor vehicles for
the United States market is less than 5,000 vehicles in a production
year.
Sec. 585.114 Definitions.
For the purposes of this subpart:
Production year means the 12-month period between September 1 of
one year and August 31 of the following year, inclusive.
Sec. 585.115 Response to inquiries.
At any time prior to August 31, 2018, each manufacturer must, upon
request from the Office of Vehicle Safety Compliance, provide
information identifying the vehicles (by make, model, and vehicle
identification number) that have been certified as complying with
Standard No. 216a (49 CFR 571.216a). The manufacturer's designation of
a vehicle as a certified vehicle is irrevocable. Upon request, the
manufacturer also must specify whether it intends to utilize carry-
forward credits, and the vehicles to which those credits relate.
Sec. 585.116 Reporting requirements.
(a) General reporting requirements. Within 60 days after the end of
the production years ending August 31, 2013, August 31, 2014, and
August 31, 2015, each manufacturer must submit a report to the National
Highway Traffic Safety Administration concerning its compliance with
Standard No. 216a (49 CFR 571.216a) for its passenger cars,
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating of less than 2,722 kilograms (6,000 pounds) produced in
that year. Each report must --
(1) Identify the manufacturer;
(2) State the full name, title, and address of the official
responsible for preparing the report;
(3) Identify the production year being reported on;
(4) Contain a statement regarding whether or not the manufacturer
complied with the requirements of Standard No. 216a (49 CFR 571.216a)
for the period covered by the report and the basis for that statement;
(5) Provide the information specified in paragraph (b) of this
section;
(6) Be written in the English language; and
(7) Be submitted to: Administrator, National Highway Traffic Safety
Administration, 1200 New Jersey Avenue, SE., Washington, DC 20590.
(b) Report content--(1) Basis for statement of compliance. Each
manufacturer must provide the number of passenger cars, multipurpose
passenger vehicles, trucks, and buses with a gross vehicle weight
rating of 2,722 kilograms (6,000 pounds) or less, manufactured for sale
in the United States for each of the three previous production years,
or, at the manufacturer's option, for the current production year. A
new manufacturer that has not previously manufactured these vehicles
for sale in the United States must report the number of such vehicles
manufactured during the current production year.
(2) Production. Each manufacturer must report for the production
year for which the report is filed: the number of passenger cars,
multipurpose passenger vehicles, trucks, and buses with a gross vehicle
weight rating of 2,722 kilograms (6,000 pounds) or less that meet
Standard No. 216a (49 CFR 571.216a).
(3) Statement regarding compliance. Each manufacturer must provide
a statement regarding whether or not the manufacturer complied with the
requirements of Standard No. 216a (49 CFR 571.216a) as applicable to
the period covered by the report, and the basis for that statement.
This statement must include an explanation concerning the use of any
carry-forward credits.
(4) Vehicles produced by more than one manufacturer. Each
manufacturer whose reporting of information is affected by one or more
of the express written contracts permitted by S8.6.2 of Standard No.
216a (49 CFR 571.216a) must:
(i) Report the existence of each contract, including the names of
all parties to the contract, and explain how the contract affects the
report being submitted.
(ii) Report the actual number of vehicles covered by each contract.
Sec. 585.117 Records.
Each manufacturer must maintain records of the Vehicle
Identification Number for each vehicle for which information is
reported under Sec. 585.116(b)(2) until December 31, 2018.
Issued on: April 30, 2009.
Ronald L. Medford,
Acting Deputy Administrator.
Appendix A--Analysis of Comments Concerning Dynamic Testing
NHTSA did not propose a dynamic test procedure in the NPRM or
the SNPRM. However, in the NPRM, we discussed comments received in
response to our October 2001 RFC concerning whether we should
include some type of dynamic test as part of the roof crush
resistance standard. We discussed several types of dynamic tests,
including the inverted drop test, the FMVSS No. 208 dolly test, the
Controlled Rollover Impact System (CRIS) test, and the Jordan
Rollover System (JRS) test. We identified a number of concerns about
using these tests in FMVSS No. 216. We noted our belief that the
current quasi-static test procedure is repeatable and capable of
simulating real-world rollover deformation patterns. We also stated
that we were unaware of any dynamic test procedures that provide a
sufficiently repeatable test environment.
Several consumer advocacy organizations and a number of other
commenters argued that the agency should propose a dynamic test
procedure in lieu of the proposed quasi-static test. Ms. Lawlor and
Mr. Clough suggested a dynamic rollover test is more reflective of
real-world rollovers. Boyle et al. suggested that a dynamic test
would provide the most accurate data for regulation. Mr. Turner
recommended that such a test would better measure the comprehensive
interaction among safety systems in a rollover crash. Mr. Friedman
and the Center for Injury Research (CFIR) recommended the use of the
JRS or a modified FMVSS No. 208 dolly rollover test. Mr. Friedman
further stated that when given the chance, engineers design the
structure to
[[Page 22389]]
deal with the dynamic impact realities required to protect occupants
and not to meet what he characterized as a vaguely related criteria
like SWR.
DVExperts asserted that a static test, such as FMVSS No. 216 or
any variation on this, is not an effective rollover performance
test, just as a load test would be considered defective for frontal
or side impacts. Public Citizen recommended a dynamic test because
it can be improved to better simulate a rollover. It believes a
static test is inappropriate for a roof crush test.
Advocates stated that a dynamic test would show how to model
occupant injury mechanisms and their prevention to provide
substantially enhanced roof crush resistance. Both Advocates and
Public Citizen recommended the development of a biofidelic rollover
anthropomorphic test device (ATD) to measure forces accurately in a
dynamic test. Syson stated that although some aspects of real
rollover crashes are not representative in dynamic tests, useful
engineering information can be obtained from the results. Syson also
expressed concern with including a dummy in dynamic testing because
biofidelic problems may help obscure the consequences of roof
failure or safety belt performance.
As indicated above, some of the commenters recommending a
dynamic test cited potential benefits related to aspects of
performance other than roof crush resistance, e.g., measuring the
performance of seat belts, doors, ejection. We note that the
suitability of a particular dynamic test must be assessed separately
for each aspect of performance that would be addressed. In this
rulemaking, we are addressing roof crush resistance, and our
discussion and analysis of the comments focus on that issue. Our
discussion and analysis below in some instances cite potential
problems related to measuring other aspects of performance which
might be measured during a test that evaluates roof crush
resistance. However, we emphasize that our discussion/analysis does
not in any way represent an assessment by the agency as to whether
any of the tests would be suitable for addressing aspects of
performance other than roof crush resistance.
FMVSS No. 208 Dolly Rollover Test
Section 5.3 of FMVSS No. 208 contains a dynamic test commonly
known as the ``dolly rollover test.'' This test was part of early
provisions in FMVSS No. 208 which permitted manufacturers the option
of providing automatic crash protection in lateral and rollover
crashes instead of seat belts. We believe that no manufacturer ever
selected the option for purposes of complying with FMVSS No. 208.
Selection of the option was ultimately precluded by the Intermodal
Surface Transportation Efficiency Act of 1991, which required the
installation of lap/shoulder belts. FMVSS No. 216 has long contained
a provision that excludes vehicles that conform to the S5.3 rollover
test requirements of FMVSS No. 208 by means that require no action
by vehicle occupants. We are unaware of any vehicle that has been
certified to S5.3 in lieu of FMVSS No. 216.
As discussed in our August 2005 NPRM, the FMVSS No. 208 dolly
test was originally developed only as an occupant containment test
and not to evaluate the loads on specified vehicle components. While
S5.3 of FMVSS No. 208 specifies that an unbelted Hybrid III 50th
percentile adult male dummy must be retained inside the vehicle
during the test, it does not specify roof strength performance
criteria or injury assessment reference values that must be met. We
stated in the NPRM that we believed that this test lacks sufficient
repeatability to serve as a structural component compliance
requirement.
A number of commenters recommended that the agency propose a
dolly rollover test. Advocates, Bidez & Associates (Bidez), SRS,
Public Citizen, CFIR and Mr. Friedman cited use of the dolly
rollover test in the Volvo XC90 development program. Several
commenters stated that the dolly rollover test remains an option for
certification in lieu of FMVSS No. 216.
Advocates and Bidez disagreed with the agency's statement that
the dolly rollover test is not sufficiently repeatable. Bidez
presented data from three dolly rollover tests conducted for Ford at
the Autoliv Test Center to support its position. Bidez concluded
that the test was repeatable based on the timing similarities of the
peak neck forces and moments.
Ford submitted additional comments refuting Bidez's conclusions
and claimed the wide range of amplitude and timing for the occupant
injury measures were not repeatable.
CFIR also stated that dynamic rollover tests have been widely
used to qualify safety devices. It stated they are repeatable in
that the initial conditions are highly controlled, and it stated
that a vehicle designed to pass can do so repeatedly. CFIR also
acknowledged, however, that dolly rollover tests do not reproduce
the same initial roof-to-ground contact conditions and small changes
can cause large differences in vehicle trajectory and dummy
kinematics.
In support of a dynamic test such as the dolly test, Technical
Services commented that while dolly rollover tests do not produce
occupant kinematics that are representative of highway rollovers,
they represent a more difficult test for the vehicle because of the
lateral component.
Agency Response
While the FMVSS No. 208 dolly rollover test has long been an
option for manufacturers in lieu of the FMVSS No. 216 test, it is an
option that they have never used. Thus, there has not been any
experience with using that test for purposes of compliance with an
FMVSS.
Moreover, as noted above, the test was not developed to evaluate
the loads on specified vehicle components. While S5.3 of FMVSS No.
208 specifies that an unbelted Hybrid III 50th percentile adult male
dummy be retained inside the vehicle, it does not specify roof
strength performance criteria or injury assessment reference values
that must be met.
Some commenters stated the dolly test was used in the
development of the Volvo XC90 and is therefore an accepted industry
practice. We note, however, that there is a significant difference
between vehicle development work by manufacturers and objective test
procedures needed for a FMVSS.
No commenters provided data demonstrating that the agency's
concerns about the dolly test lacking sufficient repeatability to
serve as a vehicle structural component compliance requirement for
assessing roof strength are unfounded. We note that our research is
consistent with the comments from CFIR concerning reproducibility
problems with respect to initial roof to ground contact conditions.
We believe that reproducibility in that area would be an important
issue for measurement of roof intrusion in an FMVSS.
In response to Bidez, we agree that the ``timing'' of peak axial
neck force was similar in their submitted test data; however, we
also noted that the magnitudes of the neck forces varied
considerably (from 260 N to 5,933 N) for the passenger side dummy of
a driver side leading test. Further, the moments and forces for the
driver side dummy also experienced wide ranges in values despite the
similar timing of the event. Given the wide range of reported peak
loads and moments, we are not convinced that repeatable timing is
more important than repeatable peak values in the injury
measurements.
The Bidez test data further showed the variation in the range of
post-test headroom for these three dolly rollover tests. In two
tests, the driver post test headroom increased 212 mm and 444 mm
(8.3 inches and 15.5 inches), but in the third test, it decreased 31
mm (-5.9 inches). The passenger side showed similar results. It
should also be noted that the measured headroom difference between
the driver's and passenger's side in each test were relatively
similar. This suggested that the roof deformed equally on both sides
but the amount of deformation differed from test to test. These
results suggest that the current dolly rollover test is not
repeatable as a roof crush test.
As stated in the NPRM, the agency has conducted prior dolly
testing (similar to the FMVSS No. 208 dolly rollover test) and
determined that the test conditions were so severe that it was
difficult to identify which vehicles had better performing roofs.
Based on these, and other dynamic tests, the agency decided that it
was best to pursue an upgraded quasi-static test for this
rulemaking.
Jordan Rollover System (JRS)
There were a range of comments related to the Jordan Rollover
System (JRS) test. The JRS device rotates a vehicle body structure
on a rotating apparatus (``spit'') while the road surface platform
moves a track underneath the vehicle and contacts the roof
structure. Comments on the JRS were submitted by the following
groups: Advocates, CFIR, DVExperts, Xprts, and Public Citizen. Some
commenters recommended developing a safety standard using the test
procedure, while others recommended that the agency undertake a
research program and investigate the JRS fully.
Advocates recommended using the JRS procedure. CFIR provided
information concerning the JRS test procedure and addressing
repeatability of the initial conditions, including data from their
JRS
[[Page 22390]]
research program. DVExperts claimed the JRS is a repeatable,
practical, and scientifically valid dynamic rollover test procedure.
Xprts submitted summary results from JRS testing of a Jeep Grand
Cherokee. It identified roof intrusion velocities and roof
deformation behavior (buckling) as important criteria for
determining injury. Public Citizen commented that NHTSA should
thoroughly investigate the JRS. Public Citizen and CFIR also
commented that the JRS test can be conducted with dummies that
demonstrate whether vehicle roof performance meets objective injury
and ejection criteria for belted and unbelted occupants.
CFIR also recommended a maximum axial neck load injury
measurement (Fz) of 7,000 N \50\ (1,574 pounds) using the Hybrid III
dummy in the JRS. The recommendation was based on cadaver and dummy
drop and impact tests. CFIR also acknowledged that the Hybrid III
dummy has poor biofidelity in the rollover mode. As an alternative,
it recommended using the roof velocity and intrusion amplitude, as
measured by an array of string potentiometers attached to the roof.
The criteria were based on its axial neck load research. CFIR
claimed to have found a good correlation between neck injury and the
speed of head impact.
---------------------------------------------------------------------------
\50\ Friedman D., Nash C.E., ``Advanced Roof Design for Occupant
Protection,'' 17th ESV Conference, Amsterdam, 2002
---------------------------------------------------------------------------
In response to the SNPRM, CAS and CFIR submitted additional
instrumented test data using the JRS \51\ equipped with a Hybrid III
dummy. The test vehicles were selected from the agency's fleet
evaluation. They argued, based upon the data, the JRS is highly
controlled and repeatable. They further suggested that the
equipment, and the test costs are modest. The test conditions can be
widely varied to emulate actual rollover conditions.
---------------------------------------------------------------------------
\51\ See Docket NHTSA 2008-0015: 2003 Subaru Forester, 2004
Subaru Forest, 2004 Volvo XC90, 2006 Chrysler 300, 2006 Hyundai
Sonata.
---------------------------------------------------------------------------
Mr. Nash provided an analysis of NASS rollover cases. He
concluded that the FMVSS No. 216 platen test would not stress the
windshield header and create the type of buckling shown in the NASS
cases. Mr. Nash claimed that the dynamic JRS test would identify the
header deformation.
Agency Response
While a number of commenters indicated support for the JRS
dynamic test procedure, and the developers submitted data for
multiple tests, the agency has remaining questions regarding the
setup, conduct, and evaluation of the JRS test procedure despite
witnessing the JRS testing in February 2007 and multiple other
meetings. All commenters relied on the JRS tests conducted and
reported by CFIR and Xprts.
After considering the data submitted, we believe there are a
large number of unresolved technical issues related to the JRS with
respect to whether it would be suitable as a potential test
procedure to replicate real-world crash damage patterns for a safety
standard evaluating vehicle roof crush structural integrity. These
include:
Test Parameters
Determination of the drop height (for different
vehicles)--The JRS releases the test vehicle from a predetermined
drop height to fall onto a moving roadway. The ideal drop height is
not known. If the drop height is not correlated with real world
data, some vehicles could be overloaded beyond what would be
representative of real world crashes. Other vehicles could be under-
exercised based on accident conditions. A specific drop height or
drop height methodology would need to be sensitive to the vehicle
types and crash conditions in the fleet.
Determination of the roll rate and roll angle at
vehicle release (for different vehicles)--The JRS releases the test
vehicle at a predetermined roll rate. The roll rate, drop height,
and angle at which the vehicle is released are carefully coordinated
to obtain an initial contact between the vehicle and the moving
roadway at the nearside A-pillar/roof junction. While advocates of
the test present anecdotal support for the test conditions, the
appropriateness of the specific test conditions is not clear. There
may be many vehicles that miss contacting the near side A-pillar/
roof junction and have first contact with the far side of the roof.
Roll rate has a role in the duration of the load on the roof and
could have a significant effect on the roof performance during the
test. If the roll rate is too slow, intrusion could be minimal. If
the roll rate is too fast, intrusion could be excessive. We believe
there is a need to correlate these parameters to real world data,
which we do not have.
Determination of the roadway speed and road surface--
The JRS drops the vehicle onto an instrumented moving roadway that
is covered with sandpaper to represent the vehicle-to-ground
interaction. The roadway speed and the vehicle-to-ground friction
play a significant role in controlling the transfer of momentum
between the rotating vehicle and the moving roadway. Changing the
roadway speed may affect how the vehicle interacts with the ground
for the far side contact. Research would be necessary to understand
this interaction and how the initial contact conditions affect the
JRS test kinematics.
Repeatability of the drop height, roll rate, release
angle, initial contact with the roadway and roadway speed--Any
regulatory test needs to be repeatable and enforceable. The agency
does not have any experience with the JRS to know what its operating
tolerances are. If it is possible to first determine optimum or
representative conditions, it is then necessary to determine the
accuracy and repeatability that a test device can provide for those
conditions using a wide variety of vehicle sizes and shapes. For
example, there are some concerns about whether some vehicle sizes or
shapes (such as the Sprinter van) would be suitable for testing with
a JRS device.
Vehicle performance criteria and instrumentation--There
are no generally accepted criteria to evaluate vehicle performance
in rollover crashes. We would need to investigate measurement
devices for relevancy with the JRS.
Initial lateral acceleration--The JRS does not take
into account the initial lateral acceleration in a real world
rollover. This may have implications when testing with a dummy and
potentially measuring performance related to some safety
countermeasures (e.g., ejection containment side curtain bags and
pretensioners). If a dummy's position in the test is not correlated
to real-world rollovers, then the assessment of pretensioners and
side window air bags in the JRS test is put into question.
Lack of Real-World Data To Feed Into the Test Parameters
At this time, NHTSA has only limited event data
recorder (EDR) data from rollover sensor-equipped vehicles. It is
hoped that data from these vehicles can provide a better
understanding of the range of initial roll rate and trip angles for
real world rollover crashes. As voluntarily-installed EDRs continue
to be installed in the fleet, the agency will gather an increasing
amount of data on real world rollover crashes. Currently, the agency
does not have enough of these data to evaluate how the JRS test
might be optimized to real world rollover conditions.
The ongoing implementation of ESC systems complicates
the evaluation of real world rollover crashes. ESC systems are
anticipated to be highly effective in reducing single vehicle
rollover crashes. These crashes tend to have the highest number of
quarter turns. The federally mandated implementation of ESC systems
is expected to dramatically alter the distribution of rollover crash
conditions.
Assuming that real world representative test conditions
could be established, NHTSA would still need to conduct a fleet
study to examine the safety performance in a JRS test, evaluate how
well the test results relate to real world safety performance, and
determine whether or not there would be any appreciable safety
improvement beyond existing FMVSSs.
Test Dummy Issues
Lack of test dummy and injury criteria--At this time,
no anthropomorphic test device (ATD) or crash test dummy, has been
designed for use in rollover crash tests. Existing ATDs used in
rollover crash tests, such as the Hybrid III dummy lack lateral
kinematic behavior as well as lateral impact biofidelity. In
addition, new injury criteria beyond those currently developed for
frontal and side impacts would need to be developed for the types of
loading conditions that result in head, neck, and face injuries
associated with roof contact.
Repeatability of test dummy and initial restraint
positioning--Because the JRS is spinning prior to initiating the
vehicle test, there are concerns about how to establish the initial
belt position on the ATD in a manner that is consistent with real
world conditions. The lateral acceleration prior to rollover
initiation (as discussed previously) can cause a belted occupant to
introduce slack in the belt. There is also the additional
complication of the timing for firing the rollover curtains and/or
pretensioners in the JRS pre-spin cycle.
There are also issues concerning the biomechanical basis for the
CFIR
[[Page 22391]]
recommended performance criteria. Specifically, we have concerns
about CFIR recommended axial neck load criteria, and the surrogate
(intrusion speed and amplitude), having potential to predict neck
injury in the real world. We note that in response to CFIR's injury
metrics, Nissan submitted an analysis conducted by David C. Viano,
Ph.D. from ProBiomechanics evaluating their findings. Viano found no
correlation between impact force and head impact velocity based upon
the available cadaver data CFIR used in its analysis. We believe
this is an important issue, and believe that lateral moments may be
equally or more significant than axial force in predicting cervical
spine injuries. Absent other information we believe further research
would be needed as to whether the recommended neck axial loads and/
or roof intrusion velocity are appropriate criteria.
As to the issue raised by Mr. Nash, the agency reviewed the
Toyota NASS cases he provided, and the damage patterns to the roof
were consistent with other cases the agency has analyzed. Neither
the agency nor Mr. Nash identified a catastrophic collapse of the
header. The integrity of the roof was maintained in all but one of
the crash events cited. NHTSA also reviewed the JRS 2007 Toyota
Camry tests and compared the results to the NASS data. The Camry was
tested twice on the driver's side of the vehicle. When the driver's
side was tested the first time, there was no appreciable damage to
the header. The driver's side of the same vehicle was then tested
again and showed some minor header damage. This test methodology is
inconsistent with a real world rollover as the far side of the
vehicle was not damaged in either JRS test and yet the driver's side
was tested twice.
While we appreciate the information provided by the commenters,
we do not believe that the information is sufficient for
consideration of the JRS as a possible test device for a Federal
motor vehicle safety standard at this time. The concept and the
ability of the fixture to rotate a vehicle and contact the roadway
have been demonstrated. However, as indicated above, there are
numerous technical issues related to the test and potential
parameters as well as a suitable ATD and associated injury criteria
or other metric.
Controlled Rollover Impact System (CRIS)
In the NPRM, NHTSA stated its belief that the CRIS device is
helpful in understanding occupant kinematics during rollover
crashes. However, we also stated that we believe that the device
does not provide the level of repeatability needed for a regulatory
requirement, because the CRIS test is repeatable only up to the
initial contact with the ground. After initial roof impact, the CRIS
test allows the vehicle to continue rolling, resulting in an
unrepeatable test condition.
Two commenters provided support for the CRIS test procedure. The
commenters were CFIR \52\ and Technical Services. CFIR provided
summary information on the repeatability of the initial conditions,
and certain occupant injury measures for the CRIS test procedure.
Technical Services recommended that the CRIS test should be
considered by the agency for dynamic roof crush testing.
---------------------------------------------------------------------------
\52\ Peltez submitted comments from the Center for Injury
Research (CFIR) dated March 22, 2004. This was originally submitted
to Docket 1999-5572 (submission 12).
---------------------------------------------------------------------------
Agency Response
The CRIS test procedure was developed to produce repeatable
vehicle and occupant kinematics for the initial vehicle-to-ground
contact. No data have been provided indicating that the procedure is
repeatable after initial ground contact, and we would not expect it
to be given that the CRIS test allows the vehicle to continue
rolling. While it is notable that some of the injury criteria appear
to be repeatable for the first ground contact, the relevance of the
dummy measurements for rollover impacts has not been established.
Evaluating performance criteria for the CRIS test would depend upon
the development of an ATD with biofidelity in rollover crash tests.
We believe a long-term research program would be necessary to
develop performance measures, evaluate the repeatability,
reproducibility, and any potential real world correlation of this
test procedure.
Inverted Vehicle Drop Test
In the NPRM, the agency stated that its research found that the
inverted drop test does not replicate real-world rollovers better
than the current quasi-static test. We stated further that the
inverted drop test does not produce results as repeatable as the
quasi-static method.
The agency received three comments on the inverted vehicle drop
test. Commenters included SAFE, Syson, and Technical Services. SAFE
commented that the inverted drop test is superior to the quasi-
static test because: (1) It is a dynamic evaluation; (2) it could
evaluate multiple rollover safety systems; (3) it could incorporate
restraint system effectiveness; and (4) it is a simple test
procedure. Syson stated that the inverted vehicle drop test
procedure provides more useful information about roof structure
performance. Technical Services questioned the value of an inverted
vehicle drop test less than 3 feet in height and the lack of lateral
loading, when compared to other dynamic dolly rollover tests.
Agency Response
We discussed issues related to the inverted drop test procedure
at some length in the NPRM, including a discussion of agency
research. NHTSA has previously conducted a test program to evaluate
the relative merits of drop testing compared to the current quasi-
static test procedure. The previous evaluation concluded that
without a rollover ATD the roof drop test could not provide a
complete safety performance test. If the test requirement is limited
to measuring roof deformation as a surrogate for occupant injury
potential, then the more controlled and repeatable quasi-static test
procedure is preferable. The agency's research indicated that the
static test can be related to the drop test with a moderate degree
of accuracy. Because of an additional number of uncontrolled
variables, such as consistent vehicle release, impact location and
deformation measurements, drop test results can be expected to vary
significantly, even for seemingly comparable test conditions.\53\
Adding a lateral component to this test procedure to address
concerns identified by Technical Services would add another level of
complexity. The comments do not provide data or arguments to refute
the positions taken by NHTSA in the NPRM.
---------------------------------------------------------------------------
\53\ Glen C. Rains and Mike Van Voorhis, ``Quasi Static and
Dynamic Roof Crush Testing,'' DOT HS 808-873, 1998.
---------------------------------------------------------------------------
Weight Drop Onto the Roof Test (WDORT)
In the NPRM, NHTSA did not discuss the weight drop onto the roof
test (WDORT) since commenters on the prior roof crush resistance
notice had not addressed this test. One commenter, Mr. Chu,
recommended that NHTSA develop a dynamic WDORT and set the dynamic
intrusion limit as a percentage of the headroom before impact. Chu
stated the WDORT is not sensitive to a vehicle's CG like the
inverted vehicle drop test and the test weight can be calibrated and
guided within four rails during the drop. Mr. Chu did not provide a
detailed test setup, procedure or test data to support his
recommendation.
Agency Response
No details or test data were provided for the WDORT concept.
Consequently, a considerable research effort would be required to
evaluate the appropriateness and practicability of such an approach
and whether it would provide any safety benefit beyond the quasi-
static procedure.
Appendix B--Two-Sided Test Results
------------------------------------------------------------------------
Peak SWR prior to
127 mm of platen
travel or head Peak force
Vehicle contact (except as change
noted) (percent)
----------------------
1st Side 2nd Side
------------------------------------------------------------------------
2007 Toyota Tundra................... 3.3 2.2 -17.5
2008 Honda Accord **................. 3.5 4.0 n/a
[[Page 22392]]
2007 Ford Edge....................... 3.3 3.2 -3.6
2007 Chevrolet Colorado.............. 2.2 1.7 -21.4
2007 Toyota Tacoma................... 3.3 3.7 12.4
2007 Chevrolet Express ***........... 2.3 1.7 -27.3
2007 Jeep Grand Cherokee............. 2.2 1.6 -27.1
2007 Pontiac G6...................... 2.3 1.7 -23.8
2005 Lincoln LS *.................... 2.6 2.0 -21.3
2007 Saturn Outlook.................. 2.7 2.2 -20.8
2003 Ford Crown Victoria *........... 2.0 1.7 -19.5
2007 Ford F-150...................... 2.3 1.9 -19.0
2007 Chevrolet Tahoe................. 2.1 1.7 -16.4
2007 Toyota Yaris.................... 4.0 3.4 -15.8
2005 Buick LaCrosse.................. 2.6 2.2 -13.5
2007 Toyota Tacoma................... 4.4 3.9 -12.2
2007 Buick Lucerne................... 2.3 2.1 -10.8
2003 Chevrolet Impala *.............. 2.9 2.5 -9.9
2004 Lincoln LS *.................... 2.5 2.2 -8.7
2006 Subaru Tribeca.................. 3.9 3.5 -8.3
2007 Scion tC........................ 4.6 4.3 -6.7
2006 Chrysler Crossfire.............. 2.9 2.7 -5.6
2007 Dodge Caravan................... 3.0 2.9 -5.3
2007 Honda CRV....................... 2.6 2.5 -4.9
2005 Buick LaCrosse.................. 2.4 2.3 -3.4
2004 Nissan Quest *.................. 2.8 2.7 -3.0
2001 GMC Sierra *.................... 1.9 1.9 -1.3
2007 Chrysler 300.................... 2.5 2.5 1.6
2004 Chrysler Pacifica *............. 2.2 2.4 7.0
2007 Toyota Camry.................... 4.3 4.7 9.0
2004 Land Rover Freelander *......... 1.7 2.0 19.2
------------------------------------------------------------------------
* Crush of first side stopped at windshield cracking.
** First side test stopped at predetermined SWR.
*** Between the first and second side tests, the front door on the
tested side was opened. Because of damage to the vehicle during the
first side test, the door would not properly close. The door was
clamped until the latch engaged, locking the door in place. This may
have compromised the structural integrity of the roof and reduced the
measured peak load on the second side.
Appendix C--Single-Sided Test Results
----------------------------------------------------------------------------------------------------------------
Peak strength within Peak strength prior Platen
Unloaded 127 mm of platen to head contact travel at
Vehicle vehicle travel ---------------------- head
weight ---------------------- contact
(kg) N SWR N SWR (mm)
----------------------------------------------------------------------------------------------------------------
2006 VW Jetta................................ 1,443 72,613 5.1 72,613 5.1 158
2007 Scion tC................................ 1,326 59,749 4.6 59,749 4.6 113
2006 Volvo XC90.............................. 2,020 90,188 4.6 N/A N/A N/A
2006 Honda Civic............................. 1,251 55,207 4.5 55,207 4.5 177
2007 Toyota Tacoma........................... 1,489 64,441 4.4 64,441 4.4 123
2006 Mazda 5................................. 1,535 66,621 4.4 66,621 4.4 155
2007 Toyota Camry............................ 1,468 62,097 4.3 62,097 4.3 N/A
2007 Toyota Yaris............................ 1,038 41,073 4 41,073 4 115
2006 Ford 500................................ 1,657 63,181 3.9 63,181 3.9 150
2007 Nissan Frontier......................... 1,615 62,828 3.9 62,828 3.9 167
2006 Subaru Tribeca.......................... 1,907 72,306 3.9 72,306 3.9 112
2006 Mitsubishi Eclipse...................... 1,485 51,711 3.6 51,711 3.6 127
2008 Honda Accord \**\....................... 1,476 50,959 3.5 50,959 3.5 N/A
2006 Hummer H3............................... 2,128 70,264 3.4 70,264 3.4 185
2007 Toyota Tacoma........................... 1,752 56,555 3.3 56,555 3.3 N/A
2007 Toyota Tundra........................... 2,345 76,216 3.3 76,216 3.3 N/A
2007 Ford Edge............................... 1,919 61,910 3.3 61,910 3.3 N/A
2006 Hyundai Sonata.......................... 1,505 46,662 3.2 46,662 3.2 131
2007 Dodge Caravan........................... 1,759 52,436 3 52,436 3 N/A
2006 Chrysler Crossfire...................... 1,357 38,179 2.9 38,179 2.9 107
2004 Honda Accord............................ 1,413 38,281 2.8 38,281 2.8 140
2007 Saturn Outlook \*\...................... 2,133 57,222 2.7 57,222 2.7 N/A
2006 Ford Mustang............................ 1,527 40,101 2.7 41,822 2.8 132
2005 Buick Lacrosse.......................... 1,590 40,345 2.6 40,345 2.6 126
2006 Sprinter Van \*\........................ 1,946 49,073 2.6 N/A N/A N/A
[[Page 22393]]
2004 Cadillac SRX............................ 1,961 50,346 2.6 50,346 2.6 138
2007 Honda CRV............................... 1,529 38,637 2.6 38,637 2.6 N/A
2007 Chrysler 300............................ 1,684 41,257 2.5 41,257 2.5 N/A
2005 Buick Lacrosse.......................... 1,588 37,196 2.4 37,196 2.4 123
2006 Honda Ridgeline......................... 2,036 47,334 2.4 47,334 2.4 172
2007 Ford F-150 \*\.......................... 2,413 54,829 2.3 54,829 2.3 N/A
2007 Buick Lucerne........................... 1,690 38,268 2.3 38,268 2.3 N/A
2004 Chevrolet 2500 HD \*\................... 2,450 55,934 2.3 56,294 2.3 171
2007 Pontiac G6.............................. 1,497 33,393 2.3 33,393 2.3 124
2007 Chevrolet Express \*\................... 2,471 55,038 2.3 55,038 2.3 N/A
2007 Jeep Grand Cherokee..................... 1,941 41,582 2.2 41,582 2.2 117
2007 Chevrolet Colorado...................... 1,560 33,299 2.2 33,299 2.2 N/A
2007 Chevrolet Tahoe \*\..................... 2,462 49,878 2.1 49,878 2.1 N/A
2006 Dodge Ram \*\........................... 2,287 37,596 1.7 42,578 1.9 158
2003 Ford F-250 \*\.......................... 2,658 44,776 1.7 44,776 1.7 205
----------------------------------------------------------------------------------------------------------------
\*\ GVWR greater than 6,000 pounds.
\**\ Test stopped at 3.5 SWR.
[FR Doc. E9-10431 Filed 5-11-09; 8:45 am]
BILLING CODE C