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\
---------------------------------------------------------------------------
\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.
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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.
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\27\ See report, Finite Element Simulation of FMVSS No. 216 Test
Procedures, placed in the docket with this notice.
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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.
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\29\ See report, Two-Sided Roof Crush Strength Analysis, placed
in the docket of this notice.
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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 th> 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.
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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.
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