[Federal Register Volume 62, Number 53 (Wednesday, March 19, 1997)]
[Rules and Regulations]
[Pages 12960-12975]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-6954]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 74-14; Notice 114]
RIN 2127--AG59
Federal Motor Vehicle Safety Standards; Occupant Crash Protection
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Final rule.
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SUMMARY: NHTSA is temporarily amending the agency's occupant crash
protection standard to ensure that vehicle manufacturers can quickly
depower all air bags so that they inflate less aggressively. The agency
is taking this action to provide an immediate, but interim, solution to
the problem of the fatalities and injuries that current air bag designs
are causing in relatively low speed crashes to small, but growing
numbers of children, and occasionally to adult occupants.
DATES: Effective Date: The amendments made in this rule are effective
March 19, 1997.
Incorporation by reference. The incorporation by reference of a
publication listed in the regulation is approved by the Director of the
Federal Register as of March 19, 1997.
Petitions: Petitions for reconsideration must be received by May 5,
1997.
ADDRESSES: Petitions for reconsideration should refer to the docket and
notice number of this notice and be submitted to: Administrator,
National Highway Traffic Safety Administration, 400 Seventh Street, SW,
Washington, DC 20590.
FOR FURTHER INFORMATION CONTACT: For information about air bags and
related rulemakings: Visit the NHTSA web site at http://
www.nhtsa.dot.gov and select ``AIR BAGS: Information about air bags.''
For non-legal issues: Mr. Clarke Harper, Chief, Light Duty Vehicle
Division, NPS-11, National Highway Traffic Safety Administration, 400
Seventh Street, SW, Washington, DC 20590. Telephone: (202) 366-2264.
Fax: (202) 366-4329.
For legal issues: J. Edward Glancy, Office of Chief Counsel, NCC-
20, National Highway Traffic Safety Administration, 400 Seventh Street,
SW, Washington, DC 20590. Telephone: (202) 366-2992. Fax: (202) 366-
3820.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Background.
A. Air Bags: Safety Issues.
B. Current Requirements for Air Bags.
II. Overview and Summary.
III. January 1997 Depowering Proposal.
IV. Summary of Comments.
V. Agency Decision.
A. Should NHTSA amend Standard No. 208 to permit/facilitate
depowering?
B. 80 g's chest injury criterion vs. sled test.
C. Application of the amendment to driver air bags.
D. Duration of amendment.
E. Benefits and trade-offs.
F. Specific sled test requirements/procedures.
1. Neck injury criteria.
2. Testing whole vehicles or partial vehicles.
3. ``Corridor'' for crash pulse.
4. Air bag activation.
5. Test attitude.
6. Completion of sled test.
G. Miscellaneous Issues.
1. Multistage manufacturer certification.
2. Effective date.
VI. Rulemaking Analyses and Notices.
I. Background
A. Air Bags: Safety Issues
Air bags have proven to be highly effective in reducing fatalities
from frontal crashes, the most prevalent fatality and injury-causing
type of crash. Those crashes result in 64 percent of all driver and
right-front passenger fatalities.
NHTSA estimates that, between 1986 and February 15, 1997, air bags
have saved 1,828 drivers and passengers (1,639 drivers and 189
passengers). Based on current levels of effectiveness, air bags will
save more than 3,000 lives each year in passenger cars and light trucks
when all light vehicles on the road are equipped with dual air bags.
This is based on current safety belt use rates (about 68 percent,
according to State-reported surveys).1 Using this assumption, more
than two-thirds of the persons saved would be persons not using any
type of safety belt.
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\1\ Some State surveys are limited to passenger cars. The
agency's latest National Occupant Protection Use Survey, a
probability-based study of safety belt use in all vehicles types,
indicates a current use rate of 58 percent. Another survey will be
conducted in 1997.
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At the same time, air bags are causing fatalities in some
situations, especially to children. As of February 15, 1997, NHTSA's
Special Crash Investigation program had identified 38 crashes in this
country in which the deployment of the passenger air bag resulted in
fatal injuries to a child. Two adult passengers have also been fatally
injured. On the
[[Page 12961]]
driver side, 21 drivers are known to have been fatally injured.2
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\2\ The agency has examined air bag cases with children in its
Fatal Analysis Reporting System (FARS) and identified no new cases.
The agency believes these 38 cases are a census of all cases that
have occurred and reported in FARS to February 15, 1997 involving
fatalities. However, the information for adult fatalities does not
represent a census. NHTSA updates air bag fatality information on a
continuing basis. The information presented in this notice and
accompanying Final Regulatory Evaluation generally reflects
information available through February 15, 1997.
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The fatalities involving children have a number of fairly
consistent characteristics. First, as to restraint usage, the infants
are in rear-facing infant restraints. The older children are generally
not using any type of restraint. Second, the crashes in which the
infants and older children were fatally injured occurred at relatively
low speeds. Third, the fatally injured infants and older children were
very close to the dashboard when the air bag deployed. Rear-facing
child seats are very close to the dashboard in a crash, even in the
absence of pre-impact braking. As to almost all of the older children,
the non-use or improper use of safety belts in conjunction with pre-
impact braking resulted in the forward movement of the children such
that they were very close to the air bag when it deployed. Because of
this proximity, the children appear to have sustained fatal head or
neck injuries from the deploying passenger air bag.
NHTSA notes that driver fatalities are very rare in comparison to
the number of vehicles equipped with driver air bags (more than 56
million vehicles, through model year 1996), and to the number of
drivers saved by air bags. The data for drivers suggest that two groups
of drivers are more at risk than other drivers from a driver air bag.
One group is older drivers. However, the agency notes that, primarily
due to their relative frailty, older drivers are more at risk than
younger drivers under a wide range of crash circumstances, regardless
of whether the older drivers use safety belts and regardless of whether
they drive vehicles equipped with air bags.
The other group of drivers is short-statured adults. Drivers five
feet two inches or shorter comprise 10 of the 21 driver fatalities the
agency is aware of to date. However, NHTSA is not aware of any
inflation-induced fatality in the United States of a female driver 5
feet 2 inches or shorter in an air bag deployment since November 1995,
16 months ago.3
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\3\ A fatality involving a 5 feet 4 inch female driver did occur
in October 1996.
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As in the case of the children fatally injured by air bags, the key
factor regarding the fatally injured adults has been their proximity to
the air bag when it deployed. The most common reason for their
proximity was failure to use safety belts. Only six of the 21 drivers
were known to be restrained by lap and shoulder belts at the time of
the crash. Moreover, of those six, two appeared to be out of position
(slumped over the wheel due to medical conditions).
B. Current Requirements for Air Bags
Under Chapter 301 of Title 49, U.S. Code (''Motor Vehicle
Safety''), NHTSA is authorized to set Federal motor vehicle safety
standards applicable to the manufacture and sale of new motor vehicles
and new motor vehicle equipment. Standard No. 208, Occupant Crash
Protection, one of the original Federal motor vehicle safety standards
issued under this statute, has long required motor vehicle
manufacturers to install safety belts to protect occupants during a
crash. Beginning in the late 1980's, the standard has required
manufacturers to provide automatic protection for frontal crashes,
i.e., protection that requires no action by the occupant.
In establishing Standard No. 208's current automatic protection
requirements for passenger cars in 1984, and later extending those
requirements to light trucks, NHTSA expressly permitted a variety of
methods of providing automatic protection, including automatic belts
and air bags. However, the agency included a number of provisions to
encourage manufacturers to install air bags. These included extra
credit during the standard's phase-in period for vehicles using air
bags and allowing vehicles with a driver air bag system to count, for a
limited period of time, as a vehicle meeting the standard's automatic
protection requirements for both driver and right-front passenger
positions.
Ultimately, however, consumer demand led to the installation of air
bags throughout the new car fleet. By the beginning of this decade,
manufacturers were rapidly moving to install air bags in all of their
passenger cars and light trucks.
Congress included a provision in the Intermodal Surface
Transportation Efficiency Act of 1991 (ISTEA) directing NHTSA to amend
Standard No. 208 to require that all passenger cars and light trucks
provide automatic protection by means of air bags. The Act required at
least 95 percent of each manufacturer's passenger cars manufactured on
or after September 1, 1996 and before September 1, 1997 to be equipped
with an air bag and a manual lap/shoulder belt at both the driver and
right front passenger seating positions. Every passenger car
manufactured on or after September 1, 1997 must be so equipped. The
same basic requirements are phased-in for light trucks one year
later.4 The final rule implementing this provision of ISTEA was
published in the Federal Register (58 FR 46551) on September 2, 1993.
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\4\ At least 80 percent of each manufacturer's light trucks
manufactured on or after September 1, 1997 and before September 1,
1998 must be equipped with an air bag and a manual lap/shoulder
belt. Every light truck manufactured on or after September 1, 1998
must be so equipped.
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Standard No. 208's automatic protection requirements, whether for
air bags or (until the provisions of ISTEA fully take effect) for
automatic belts, are performance requirements. The standard does not
specify the design of an air bag. Instead, vehicles must meet specified
injury criteria, including criteria for the head and chest, measured on
test dummies, during a barrier crash test, at speeds up to 30 mph.
These criteria must be met for air bag-equipped vehicles both when the
dummies are belted and when they are unbelted. The latter test
condition ensures that a vehicle provides ``automatic protection,''
i.e., protection by means that require no action by vehicle occupants.
These requirements apply to the performance of the vehicle as a
whole, and not to the air bag as a separate item of motor vehicle
equipment. This approach permits vehicle manufacturers to ``tune'' the
performance of the air bag to the crash pulse 5 and other specific
attributes of each of their vehicles. Further, it leaves them free to
select specific attributes for their air bags, such as dimensions and
actuation time.
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\5\ ``Crash pulse'' means the acceleration-time history of the
occupant compartment of a vehicle during a crash. This is
represented typically in terms of g's of acceleration plotted
against time in milliseconds (1/1000 second). The crash pulse
determines the test's stringency: an occupant will undergo greater
forces if the crash pulse g's are higher at the peak, or if the
duration of the crash pulse is shorter.
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II. Overview and Summary
NHTSA is implementing a comprehensive plan of rulemaking and other
actions (e.g., consumer education and encouragement of primary
enforcement of State safety belt use laws) addressing the adverse
effects of air bags. The rulemaking actions which have been taken, or
are being taken, include the following:
Interim Rulemaking Solutions
In this notice, NHTSA is temporarily amending Standard No.
208, to ensure that vehicle manufacturers can depower all air bags
[[Page 12962]]
so that they inflate less aggressively. This change, coupled with the
considerable flexibility already provided by the standard's existing
performance requirements, will provide the vehicle manufacturers
maximum flexibility to quickly address the adverse effects of current
air bags.
On November 27, 1996, the agency published in the Federal
Register (61 FR 60206) a final rule amending Standards No. 208 and No.
213 to require improved labeling on new vehicles and child restraints
to better ensure that drivers and other occupants are aware of the
dangers posed by passenger air bags to children, particularly to
children in rear-facing infant restraints in vehicles with operational
passenger air bags. The new labels were required on vehicles beginning
February 25, 1997, and are required on child restraints, beginning May
27, 1997.
On January 6, 1997, the agency published in the Federal
Register (62 FR 798) a final rule extending until September 1, 2000, a
provision in Standard No. 208 permitting vehicle manufacturers to offer
manual cutoff switches for the passenger air bag for new vehicles
without rear seats or with rear seats that are too small to accommodate
rear-facing infant restraints.
On January 6, 1997, the agency published in the Federal
Register (62 FR 831) an NPRM to permit motor vehicle dealers and repair
businesses to deactivate, upon the request of consumers, driver and
passenger air bags. The agency expects to announce a final decision on
this issue shortly.
Longer Term Rulemaking Solution
NHTSA plans to issue an NPRM to require a phasing-in of
smart air bags and to establish performance requirements for those air
bags. On February 11 and 12, 1997, the agency held a public technical
workshop to discuss appropriate test procedures and other issues
related to that forthcoming proposal. Among other things, the agency
may propose using a 5th percentile female dummy and specifying
appropriate injury criteria for that dummy, including neck injury.
In addition to these actions, the agency is participating with
automobile manufacturers, air bag suppliers, insurance companies and
safety organizations in a coalition effort to address the adverse
effects of air bags by increasing the use of safety belts and child
seats. Substantial benefits could be obtained from achieving higher
safety belt use rates. For example, if observed belt use increased from
68 percent to 80 percent, an additional 2,900 lives would be saved
annually over the 9,529 lives currently being saved by safety belts.
The coalition has a three-point program that seeks to educate the
public about safety belt and child seat use, work with state and local
officials to improve enforcement of safety belt and child seat use
laws, and seek the enactment of ``primary'' safety belt use laws.6
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\6\ In States with ``secondary'' safety belt use laws, a
motorist may be ticketed for such failure only if there is a
separate basis for stopping the motorist, such as the violation of a
separate traffic law. This hampers enforcement of the law. In States
with primary laws, a citation can be issued solely because of
failure to wear safety belts.
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A 1995 NHTSA analysis of Fatal Analysis Reporting System (FARS)
data on restraint use among fatally injured motor vehicle occupants
from 1983 to 1994 indicates that primary enforcement is the most
important aspect of a safety belt use law affecting the rate of safety
belt use. For virtually all states with a primary enforcement law,
statistically significant increases associated with the presence of
such a law were detected using several different methods. The analysis
suggests that the increase in use rates attributable to the enactment
of a primary enforcement law is at least 15 percentage points. This
increase in safety belt use translates into a 5.9 percent decline in
fatalities in a state that authorizes primary enforcement of the law.
In California and Louisiana, states which recently upgraded their laws
to allow for primary enforcement, safety belt usage increased by 13 and
17 percentage points, respectively.
III. January 1997 Depowering Proposal
On January 6, 1997, NHTSA published an NPRM (62 FR 807) to
temporarily amend Standard No. 208 to help reduce the fatalities and
injuries that current air bags are causing in relatively low speed
crashes to small, but growing numbers of children, and occasionally to
adults.
The agency believed that the proposed amendments would ensure that
vehicle manufacturers can quickly depower all air bags so that they
inflate less quickly and less aggressively. Based on agency research
and analysis regarding the optimal range of air bag depowering, the
agency tentatively concluded that an average depowering of 20 to 35
percent would reduce the risk of air bag fatalities in low speed
crashes, while substantially preserving the life-saving capabilities of
air bags in higher speed crashes.
NHTSA proposed adopting either, or both, of two different
approaches that would permit or facilitate an approximate 20 to 35
percent average depowering of current air bags. One approach was to
temporarily make it easier to meet the chest acceleration requirement
that an unbelted dummy must meet in a crash test at speeds up to 30
mph, by raising the limit from 60 g's to 80 g's. The other approach,
which appeared to allow higher levels of depowering, was to temporarily
replace vehicle crash testing using an unbelted dummy with the American
Automobile Manufacturers Association's (AAMA's) modified ``sled test''
protocol incorporating a 125 millisecond (msec) standardized crash
pulse and also using an unbelted dummy.
NHTSA recognized that while depowered air bags would provide
immediate benefits in a number of situations, they would not fully
solve the problem of adverse effects from air bags and could also
reduce protection to unbelted occupants in higher speed crashes. NHTSA
indicated that it believes the ultimate solution to the problem of
adverse effects from air bags is implementation of more advanced air
bags that adjust the deployment decision/inflation rate based on such
factors as size and position of vehicle occupants, severity of crash,
and whether safety belts are being used. The agency therefore stated in
the NPRM that it viewed depowering as an interim measure to be used
until better solutions can be implemented.
In its Preliminary Regulatory Evaluation (PRE), the agency
presented several methodologies to analyze the potential benefits and
net effects on safety associated with depowering. Two methodologies
utilized research testing and mathematical modeling results to examine
the effect of depowering on chest g's and then to estimate the effect
of chest g changes on fatalities. A third methodology examined the
experience in Australia of a General Motors-designed Holden car, which
has less aggressive air bags.
NHTSA requested commenters to provide additional information in a
number of areas, including the following:
Information and data to help the agency refine its
estimates (presented in the PRE) of the potential benefits and net
effects on safety that would be likely to result from depowering.
Information and supporting data for the specific sled
pulse recommended by AAMA.
Analysis comparing the potential benefits and net effects
on safety of the two proposed alternatives.
Information concerning the extent of the existing problem
of driver fatalities and injuries from air bags and
[[Page 12963]]
the extent to which manufacturers have already addressed the problem by
design changes to driver air bags.
Whether the same or different requirements should apply to
the passenger and driver positions, including the advisability of
limiting the proposed temporary amendment to passenger air bags only.
The appropriate duration of the temporary amendment.
IV. Summary of Comments
NHTSA received over 160 comments in response to the NPRM.
Commenters included vehicle manufacturers, air bag and component
manufacturers, safety advocacy groups, insurance groups, trade
associations, State entities, and individuals.
Most commenters agreed that the agency should issue requirements to
facilitate air bag depowering, thereby reducing injury risks related to
air bag deployment in low speed crashes. Support for depowering came
from commenters such as Advocates for Highway and Auto Safety
(Advocates), the American Automobile Manufacturers Association (AAMA),
the Association of International Automobile Manufacturers (AIAM), the
National Transportation Safety Board (NTSB), the Insurance Institute
for Highway Safety (IIHS), specific vehicle manufacturers, and the
Automotive Occupant Restraints Council (AORC). These commenters stated
that depowered air bags will improve vehicle safety by reducing the
risk posed to vehicle occupants. While the vehicle manufacturers
favored allowing depowering indefinitely, Public Citizen, Advocates,
and air bag manufacturers conditioned their support on the placing of a
time limit on depowering.
The Center for Auto Safety (CFAS), the Parents Coalition for Air
Bag Warnings, and some individuals opposed depowering. These commenters
argued that switching from a crash test to sled test with a generic,
large car crash pulse would result in an unreasonably lenient standard
that would result in a substantial increase in adult deaths.
Commenters addressed specific issues raised in the NPRM, including
whether to adopt the 80g's alternative, the sled test alternative, or
both; whether to depower both driver side and passenger side air bags;
whether to make the amendment temporary or permanent; and the
appropriateness of the agency's estimates of potential benefits and
tradeoffs in the PRE. Commenters also addressed specific issues
involving the sled test requirements and test conditions, including the
neck injury criteria, testing a portion of the vehicle or the entire
vehicle, the ``corridor'' for the crash pulse, the activation time for
the air bag during the sled test, and the vehicle test attitude.
Commenters, especially the safety groups, addressed various issues that
are not directly related to depowering, such as adopting minimum
deployment speed thresholds and undertaking a comprehensive upgrade of
Standard No. 208. A more specific discussion of the comments, and the
agency's responses, are set forth below.
V. Agency Decision
After carefully considering the comments, NHTSA has decided to
adopt AAMA's modified unbelted sled test protocol as a temporary
alternative to Standard No. 208's current unbelted crash test
requirement. This change, coupled with the considerable flexibility
already provided by the standard's performance requirements, will
provide the vehicle manufacturers with maximum flexibility to quickly
address and mitigate the adverse effects of current air bags.
A. Should NHTSA Amend Standard No. 208 To Permit/Facilitate Depowering?
As discussed above, NHTSA proposed to amend Standard No. 208 to
ensure that vehicle manufacturers can depower all air bags so that they
inflate less aggressively. The vast majority of commenters supported
depowering as a quick way of addressing the problem of adverse effects
of air bags. Commenters supporting depowering were diverse and included
AAMA and AIAM, representing essentially all domestic and import vehicle
manufacturers, AORC, representing suppliers, IIHS, Advocates, and
Public Citizen.
A few commenters, however, opposed depowering or otherwise raised
concerns about the basic approach of the agency's proposal. The issues
raised by those commenters are addressed in this section. Comments
concerning how depowering should be accomplished, e.g., what
alternative amendment should be adopted, whether the driver side should
be included, and the appropriate duration for the amendment, will be
discussed in later sections.
The Parent's Coalition recommended that NHTSA consider issuing a
final rule mandating on-off switches for air bags and a higher minimum
deployment threshold (for single level inflator air bags) in lieu of
amending Standard No. 208 to permit depowering. That organization
stated that information from NHTSA's Special Crash Investigation
Program shows that low deployment thresholds are the central cause of
air bag deaths and injuries, and that the agency erred in not including
an increased deployment threshold as part of its proposal. The Parent's
Coalition expressed concern that the contemplated level of depowering
will not save all children, and will result in an increase, perhaps a
substantial one, in adult deaths and injuries. The Parent's Coalition
stated that the increase in adult deaths from depowering appears to be
an unacceptable cost in exchange for the relatively modest reduction in
child deaths, especially since the child deaths could be prevented,
without such adverse tradeoffs, by an on-off switch and by an increase
in deployment threshold.
CFAS also urged NHTSA to look at whether a moderate increase in
deployment threshold would perform a better job of increasing vehicle
safety, before adopting the depowering proposal. CFAS also stated that
the issue before NHTSA is not whether depowered inflators should be
permitted under Standard No. 208, but whether manufacturers should be
permitted to escape responsibility for meeting the current injury
criteria of the standard. CFAS stated that Standard No. 208 does not
prohibit manufacturers from using depowered inflators.
While it did not oppose depowering as an interim measure, Consumers
Union stated that the most important step that the agency can take in
the near term to address the situation is to establish a higher
deployment threshold, on an expedited basis, a requirement for a low-
end limit to the vehicle impact level barrier equivalent velocity,
below which air bags will not be triggered to inflate.
NHTSA notes that, in its January 1997 proposal, it discussed a
variety of alternative approaches for addressing the adverse effects of
air bags, including higher deployment thresholds, dual level inflators,
smart air bags, and various other changes to air bags. In issuing its
proposal, the agency recognized that, for many vehicles, depowering has
a shorter leadtime than any of the other alternatives. The agency also
explained that a change in Standard No. 208 is not needed to permit
manufacturers to implement these other alternatives.7 The agency
explained further:
\7\ NHTSA explained that the existing provisions of Standard No.
208 already provide considerable design flexibility for
manufacturers. The Standard's automatic protection requirements are
performance requirements and do not specify the design of an air
bag. Instead, vehicles must meet specified injury criteria,
including criteria for the head and chest, measured on properly
positioned test dummies, during a barrier crash test, at speeds up
to 30 mph.
As the AAMA correctly noted in its comments on the NPRM, the
Standard requires air bags to provide protection for properly
positioned occupants (belted and unbelted) in a 30 mph crash, and
very fast air bags may be necessary to provide such protection.
However, the standard does not require the same speed of deployment
in slower speed crashes or in the presence of out-of-position
occupants. Vehicle manufacturers have the flexibility under the
Standard to use dual or multiple level inflator systems and
automatic cut-off devices for out-of-position occupants and rear-
facing infant restraints. Concepts such as dual level inflator
systems and devices that sense occupant position and measure
occupant size or weight are not new, and were cited by the agency in
its 1984 rulemaking requiring automatic protection. Also, Standard
No. 208 does not specify a minimum vehicle speed at which air bags
must deploy. Thresholds could be raised substantially for most
current vehicles without creating a Standard No. 208 compliance
problem. In addition, installation of smart air bags and replacement
of mechanical air bag sensors with electronic ones are permitted.
Therefore, regulatory changes are not needed to permit manufacturers
to implement these solutions.
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[[Page 12964]]
The agency expects to ultimately require smart air bags through
rulemaking. In the meantime, the agency is not endorsing depowering
over other solutions. Instead, the agency is proposing a regulatory
change to add depowering to the alternatives available to the
vehicle manufacturers to address this problem on a short-term basis.
To the extent that manufacturers can implement superior alternatives
for some vehicles, the agency would encourage them to do so.
NHTSA shares the concern of the Parent's Coalition that depowering
will not likely save all children and will likely result in trade-offs
for adults. That is why the agency is limiting the duration of its
depowering amendments and plans to conduct rulemaking to require smart
air bags. In the meantime, however, NHTSA wants to be sure that the
vehicle manufacturers have the necessary tools to address immediately
the problem of adverse effects of air bags. Standard No. 208's existing
performance requirements do restrict the use of depowering, since
substantially depowering the air bags of many vehicles would make those
vehicles incapable of complying with the standard's injury criteria in
a 30 mph barrier crash test. Accordingly, to permit use of this
alternative, it is necessary to amend Standard No. 208.
The issuance of any rule narrowing the discretion that vehicle
manufacturers have had since the 1984 decision, whether by requiring
depowering, higher thresholds, other changes to air bags, or smart air
bags, would involve considerably more complex issues than a rulemaking
simply adding greater flexibility. The agency would need to assess
safety effects, practicability, and leadtime for the entire vehicle
fleet. NHTSA will assess those types of issues in its rulemaking for
smart air bags. The agency notes that there may not be any reason to
have higher deployment thresholds with some types of smart air bags,
since a low-power inflation may be automatically selected for low
severity crashes.
Until the agency conducts its rulemaking regarding smart air bags,
it believes it is best to focus on ensuring that manufacturers have
appropriate flexibility to address the problem of adverse effects of
air bags. This will enable the manufacturers to select the solutions
which can be accomplished most quickly for their individual models.
NHTSA encourages the vehicle manufacturers to use the best available
alternative solutions that can be quickly implemented for their
vehicles, whether depowering, higher thresholds, other changes to air
bags, smart air bags, or a combination of the above. The agency notes
again that the vehicle manufacturers need not wait for further
rulemaking to begin installing smart air bags, and encourages them to
move in that direction expeditiously.
NHTSA notes that, as discussed in the January 1997 NPRM, CFAS and
Public Citizen petitioned the agency in November 1996 to commence a
rulemaking proceeding to consider requiring dual inflation air bags and
to specify deployment thresholds. The agency stated in that notice that
it considered the petitions to have been granted to the extent that the
NPRM analyzed and discussed issues raised by the petitioners and
subjected that material to public comment. NHTSA will continue to
consider the issues raised by those petitioners in its planned
rulemaking on smart air bags.
Consumers Union urged the agency to evaluate whether the incidence
of fatalities caused by air bags in low speed collisions may be
disproportionately high in certain specific makes and models of
passenger vehicles. That organization stated that it would be a great
disservice to the public to reduce the protection of air bags in all
cars because certain specific models are improperly designed. NHTSA
notes that while the level of risks from air bags undoubtedly varies
between different makes and models, a review of air bag fatalities
indicates that the problem is a general one, not limited to a few
makes/models.
A few commenters argued against the agency's depowering proposal on
the grounds that the proposed amendments would result in a greater
number of lives being lost than saved, both for passengers and drivers.
While the agency recognizes the possibility that there is a
potential for net disbenefits from depowering, it believes it must
consider both the short-run and long-run implications of this
rulemaking on safety. Ultimately, the continued availability of any
safety device as standard equipment, whether provided voluntarily by
manufacturers or pursuant to a regulation, is dependent on consumer
acceptability. The agency believes that air bags which fatally injure
occupants, particularly children in low speed crashes, place the
concept of air bags at risk, despite their overall net safety benefits.
Accordingly, to help ensure that air bags remain acceptable to
consumers and ultimately achieve their full potential in the future,
the agency believes it is reasonable to accept some short-term safety
tradeoffs associated with depowering, while better solutions are being
developed.
NHTSA also notes that, as discussed in the NPRM, it believes that
even if the net effect were negative, the opportunity to avoid the
deaths of a significant number of children who would otherwise be
fatally injured by air bags justifies foregoing the opportunity to save
some unbelted teenage and adult passengers. There are several reasons
for this policy choice.
First, it is not acceptable that a safety device cause a
significant number of fatalities in circumstances in which fatal or
serious injuries would not otherwise occur. In making this statement,
the agency draws a distinction between air bags which are fatally
injuring young children in low speed crashes in which the other vehicle
occupants are uninjured, and other safety devices which may on occasion
unavoidably substitute one type of injury for another type that would
occur in their absence (safety belts are a good example).8 Those
fatalities are particularly unacceptable in light of the agency's
analysis showing that depowering air bags can significantly reduce the
number of children being fatally injured by air bags.
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\8\ In severe collisions, safety belts can seriously bruise the
chest of an occupant or even cause rib fractures. However, the
restraining force of the belt would also likely prevent even more
serious chest or head injury from the occupant's striking the
interior components of the vehicle.
---------------------------------------------------------------------------
Second, it is also particularly unacceptable that the vehicle
occupants being fatally injured are young children, and that the number
of those deaths is steadily growing. In confronting the possibility of
inevitable short-term safety tradeoffs between young children and
unbelted occupants over 12 years of age, the agency believes that
greater weight must be placed on protecting
[[Page 12965]]
young children. NHTSA has always given a high priority to protecting
children and accordingly has applied these different cost-benefit
considerations to its rulemaking affecting children. The agency's
activities related to school bus safety standards are an example of
this policy.
A major reason for giving priority to protecting young children is
that they are less mature than teenagers and adults and thus less able
to exercise independent judgment, assess the risks and take action to
improve their safety. Young children are more dependent on the judgment
and actions of other persons. The oldest of the 38 children who have
been fatally injured by an air bag was nine years old, and most of the
children have been much younger. The agency is concerned about the
safety of the unbelted teenagers and adults who might be affected by
depowering, but is increasing its efforts to persuade them to protect
themselves by buckling their safety belts as required by the laws of 49
States and the District of Columbia. NHTSA is also increasing its
efforts to persuade parents to ensure that all children are properly
restrained.
B. 80 g's Chest Injury Criterion vs. Sled Test
As discussed above, Standard No. 208 currently specifies that
occupant protection is measured in a full scale crash test in which a
vehicle equipped with test dummies at the outside front seating
positions is crashed into a barrier. Specific injury criteria measured
on the test dummies, including those evaluating chest acceleration and
head injuries, must be met in barrier crashes at speeds up to 30 mph,
and at a range of angles up to 30 degrees off-center.
In August 1996, AAMA submitted a petition requesting that the
unbelted crash test requirement be replaced with a generic sled test
protocol. Under that protocol, all of a vehicle, or a portion of the
vehicle representing the interior, would be mounted on a sled. The sled
would be decelerated from 30 mph over a time period of 143 milliseconds
according to a specific deceleration-time curve which approximates a
vehicle's crash pulse. There would not be an angle test, only a direct
frontal test. AAMA requested that the same crash pulse be used for all
vehicles. That organization asserted that its recommended test protocol
would allow for lower powered inflators to be introduced into the
market as quickly as possible, while maintaining air bag protection for
all occupants.
After NHTSA conducted a vehicle test and discovered that AAMA's
initially recommended crash pulse could allow a vehicle to meet
Standard No. 208's existing injury criteria without an air bag, in
November 1996 that organization suggested using a more severe crash
pulse: 125 msec., which corresponds to 17.2 g's.9 AAMA also
recommended at that time that the agency include neck injury criteria
to evaluate air bag performance as it relates to the recommended crash
pulse, in addition to the current injury criteria which, among other
things, limit chest acceleration to 60 g's. The neck injury criteria
are likely to be the limiting factor in determining the maximum
allowable depowering level for a particular vehicle.
---------------------------------------------------------------------------
\9\ See pages III-45 and 46 of the PRE which show that the 143
millisecond pulse was significantly longer in duration and lower in
amplitude when compared to the 125 msec pulse.
---------------------------------------------------------------------------
After reviewing the available information, NHTSA proposed two
alternative temporary amendments to Standard No. 208: (1) Increase the
current chest acceleration limit from 60 g's to 80 g's, or (2) replace
the unbelted crash test requirement with a sled test protocol
incorporating the 125 millisecond crash pulse. The agency noted that if
both of these changes were adopted, a manufacturer could select either
alternative at its option, but could not mix the two options.
AAMA, AIAM, Advocates, Autoliv, Public Citizen, and all vehicle
manufacturers addressing the issue, stated that only the sled test
alternative should be adopted. AAMA stated that using the sled test
will allow further optimization of air bag performance and will save
many additional lives each year as well as substantially reduce the
risk of air bag-related injuries. That organization stated that the
sled test allows depowering for all vehicles in the quickest possible
manner.
NHTSA notes that AAMA estimated that only 31 percent of the fleet
could be depowered under the 80 g's alternative. That organization did
not provide specific data or analysis to support that figure. However,
Ford commented that neither it nor the agency has conducted angular
barrier modeling or tests that could be the basis for judging
performance of depowered air bags in angular barrier tests. Ford stated
that computer modeling by it and the agency, as well as sled tests,
indicate that HICs and femur loads increase with depowered air bags,
and Ford would have no basis for judging that vehicles equipped with
substantially depowered air bags would meet compliance criteria in
angular tests.
AIAM stated that the sled test would result in the fastest way to
achieve depowering. Nissan stated that the sled test provides the
fastest and most efficient approach to allow for depowering. Autoliv
stated that the sled test was consistent with international
harmonization. Several safety groups, including Advocates and IIHS,
favored the sled test, because they believed that it provides the
quickest way to reduce risk.
In contrast, other safety groups (CFAS, Consumers Union, and the
Parents Coalition) and some component manufacturers (AirBelt Systems,
AVS Technologies, and Precision Fabrics Group (PFG)) criticized the
sled test. CFAS stated that sled testing fails to account for many
aspects of interior vehicle safety that contribute to occupant
injuries. Consumers Union stated that the sled test is a ``wholly
inadequate substitute for whole-car crash tests in determining specific
vehicle performance.'' PFG was concerned that the generic pulse does
not consider such things as automobile crush and steering wheel
response.
IIHS was the only commenter to support use of either approach.
After reviewing the comments, NHTSA has decided to adopt the sled
test as an alternative to the current unbelted barrier test for a
limited time. The agency believes that this approach provides
manufacturers with the maximum flexibility to provide the fastest
depowering on the widest portion of the vehicle fleet. As the agency
stated in the NPRM, the sled test reduces the time and cost of doing
certification testing, since many more sled tests can be conducted in
the same time period than can crash tests. The agency also believes
that the standardized crash pulse and air bag initiation time for all
vehicles will allow commonality in air bag systems, requiring less
development time and thus eliminating the need for greater variations
of air bag system components to accommodate differences in actual car
crash pulses. Such rapid implementation is necessary to address the
potential risk posed to vehicle occupants in low speed crashes. The
agency has decided not to provide an option of complying with the 80
g's alternative, since no manufacturer indicated it planned to pursue
that approach.
As discussed in the NPRM, NHTSA continues to believe that a full
scale vehicle crash is a better means of measuring crashworthiness than
a sled test, since it evaluates many more factors about a motor
vehicle's crashworthiness than a generic sled test. The NPRM stated
that
[[Page 12966]]
The primary disadvantage of the generic sled test is that the test
measures only air bag performance and not total vehicle performance.
The approach also eliminates the effect of angle test requirements
which ensure protection in frontal impacts that occur at a range of
angles rather than purely head-on.
There are other disadvantages with the sled test, including that a
sled test does not simulate the triaxial acceleration characteristics
of an actual vehicle crash. In other words, a sled test involves
acceleration from only a single preset direction, while pulses for
actual vehicle crashes can have significant vertical and lateral
components of acceleration that can affect occupant kinematics and
restraint performance. Nor does a sled test evaluate dynamic intrusion
into and deformation of the passenger compartment; structural crush;
the steering column's energy absorbing characteristics and load bearing
capability; and movement of the passenger compartment due to localized
buckling.
Nevertheless, NHTSA has decided to allow the sled test as a
temporary 10 measure given the need to provide manufacturers with
maximum flexibility to respond rapidly to the risk posed by air bag
activation in low speed crashes.
---------------------------------------------------------------------------
10 The issue of whether to make this amendment temporary
or permanent is discussed in detail below.
---------------------------------------------------------------------------
NHTSA notes that, as discussed in the NPRM, it conducted a series
of tests using the revised AAMA crash pulse. One vehicle passed all of
Standard No. 208's current injury criteria without an air bag, but had
a very small margin of compliance for passenger chest g's. Another
vehicle met the standard's current injury criteria without an air bag
for the passenger side, but slightly exceeded the driver chest g's
limit. The agency's testing also showed that air bag deployment is
necessary for a vehicle to comply with the new neck injury criteria,
discussed later in this notice. Given that manufacturers must design
their vehicles with sufficient margin of compliance to ensure that all
vehicles will pass a standard's requirements, and given the addition of
the new neck injury criteria, the agency believes that the sled test
adopted in this rule will ensure an appropriate level of depowering
without diminishing the benefits of unbelted testing. While the agency
recognizes that the sled test is not an ideal means for ensuring that
chest and head protection are provided in specific vehicles, and that
the 30 mph generic pulse represents a barrier crash test at a speed
lower than 30 mph, NHTSA believes it is an appropriate interim approach
to help facilitate depowering.
C. Application of the Amendment to Driver Air Bags
In the NPRM, the agency noted a number of differences between the
passenger and driver air bag problems. The agency explained that while
the annual number of child fatalities is small but growing steadily,
the annual number of driver fatalities does not appear to be growing.
At the time of the NPRM, while the agency was aware of 18 children who
had been fatally injured by air bags during 1996, it was aware of only
one driver who had been fatally injured by an air bag in the United
States during that year. (As of now, the agency is aware of 22
children, and three drivers, who were killed by air bags during 1996.)
NHTSA noted in the NPRM that most child fatalities had occurred in
model year 1994 and 1995 vehicles. In contrast, only 4 of the driver
fatalities had occurred in a vehicle manufactured after model year
1992. The absence of fatalities in recent model year vehicles appeared
even more pronounced in the case of female drivers 5 feet 2 inches or
shorter. Only one female driver 5 feet 2 inches or shorter had died in
a post model year 1992 vehicle. Most fatalities of short-statured
female drivers had occurred in model year 1990-1992 vehicles. (The
figures and fatality patterns in this paragraph remain unchanged, as of
the date of issuance of this final rule, except that the number of
driver fatalities in post model year 1992 vehicles is now 5.)
The agency noted in the NPRM that because driver air bags have been
produced in large numbers for several years longer than passenger air
bags, the vehicle manufacturers have had time in a number of instances
to redesign driver air bags to incorporate a number of countermeasures
to reduce the risk to out-of-position occupants. NHTSA requested
information on the potential that current driver air bags have for
creating adverse effects, including relevant design changes that have
already been made to driver air bags.
NHTSA requested information on the number of driver air bag
fatalities that have occurred to date, and on whether there is a need
to change Standard No. 208 to permit varying levels of depowering. The
agency noted that, based on limited testing and modeling, 20 to 35
percent depowering of driver air bags appeared to result in only slight
increases in the injury levels ``experienced'' by a test dummy. NHTSA
stated that it believes that the presence of energy absorbing steering
columns explain why the driver air bag can depowered without
significantly affecting chest g's.
The vehicle manufacturers urged the agency to amend Standard No.
208 to allow depowering for the driver side as well as the passenger
side. AAMA stated that its design goal for depowering is to reduce to
as close to zero the possibility of a fifth percentile female being
injured by the air bag. That organization stated that not allowing
depowering for the driver position would continue to place these
occupants at unnecessary risk.
IIHS stated that although most public attention has focused on the
problem of air bag injuries to children, it is clear that drivers also
are being injured by inflating air bags. That organization stated that
much of its analysis has focused on the potential benefits to drivers
of depowering air bags. IIHS therefore argued that the alternative
compliance procedures proposed by NHTSA should apply to both driver and
passenger protection.
NTSB stated that given the awareness that air bags at the current
energy level can be highly injurious to both drivers and passengers, it
recommends that depowering be extended to both passenger and driver
positions.
AVS Technologies, by contrast, stated that the amendment should
apply only to the passenger side. According to that company, the
disbenefits of increased fatalities in comparison to the relatively
small number of serious deployment injuries does not justify amending
the regulation to accommodate depowered driver air bags. AVS
Technologies also argued that the problem of small statured drivers can
be mitigated by implementation of available technologies such as
adjustable steering columns that allow the small statured adult to
position the steering wheel further away from the head and chest.
In response to the NPRM, NHTSA received relatively little
information on whether there was a need to change Standard No. 208 to
permit depowering. Ford, however, stated that as air bag technology and
dummy testing technology has advanced, air bags have been gradually
depowered. That company stated that with today's technology, some early
air bags could be redesigned to meet Standard No. 208's injury criteria
with lower inflation speeds. Ford noted that tests by the agency have
demonstrated that limited depowering is being incorporated into newer
vehicle designs. Ford added, however, that most current air bag designs
(some of which are not yet in production) have already been depowered
to some degree and cannot
[[Page 12967]]
be further depowered without unduly increasing the risk of failing to
meet some of the dummy injury criteria in the present Standard No. 208
barrier crash test with unbelted dummies.
After considering the comments, NHTSA has decided to amend Standard
No. 208 to allow depowering for the driver side as well as the
passenger side. While relevant supporting data are considerably more
limited for the driver side than the passenger side, the agency wishes
to ensure that manufacturers have the flexibility to quickly address
driver side risks to small females and the elderly. NHTSA notes,
however, that fatalities involving small females and the elderly are
rare. Depowering driver air bags will also help reduce arm injuries.
D. Duration of Amendment
As indicated above, in developing the January 1997 proposal, NHTSA
considered an array of approaches that would address the air bag safety
problem. Among other things, the agency considered higher deployment
thresholds, dual stage inflators, smart air bags, and various other
air-bag related changes.
After reviewing these alternatives, NHTSA tentatively concluded
that there are various alternatives already allowed by Standard No. 208
that may be superior to depowering, i.e., alternatives that result in
equal or greater benefits without raising the possibility of adverse
safety tradeoffs, but whose leadtime is longer than that of depowering.
The agency therefore tentatively concluded that while depowering
appears to be an appropriate interim solution, there is no need for
permanently changing the Standard to enable manufacturers to fully
address the adverse side effects of air bags.
NHTSA noted that some commenters on earlier notices, including
Takata, had expressed concern that a reduction in Standard No. 208's
performance requirements may delay the introduction of superior
alternatives. The agency stated that it did not believe a short-term
temporary amendment would result in such a delay, but would instead
provide maximum flexibility to the vehicle manufacturers to quickly
address the problem, while they work on better solutions. The agency
also explained that its forthcoming proposal for smart air bags would
seek to ensure that air bags reach their full fatality and injury
reducing potential.
NHTSA recognized, however, that the proposal to permit or
facilitate depowering of air bags was on a faster track than the
rulemaking to require smart air bags. The agency noted that if it
permitted depowering until smart bags are introduced, the question
would arise of how the agency should limit the duration of the
temporary amendment for depowering. The agency noted that one approach
would be to specify a several year duration and revisit the issue in
the context of the rulemaking on smart air bags.
The agency received numerous comments concerning the appropriate
duration for the depowering amendment. The vehicle manufacturers, IIHS,
and CVC argued against including a ``sunset'' clause; a number of
safety groups and suppliers argued that a sunset for the amendment is
critical, and specifically conditioned their support for depowering
upon a sunset provision.
AAMA stated that there is no reason at this time to limit the
duration of depowering. That organization stated that reducing the
energy output of air bag inflators should be viewed as an important
step toward development of advanced technology air bags. According to
AAMA, there is no reason to assume that the current energy level of air
bags provides optimum occupant protection, especially for belted
occupants, and it would be a mistake to assume that it must be
reinstated after some interim period. AAMA argued that its analyses
show that depowering alone can save many additional lives per year
compared to today's air bag energy levels.
AAMA also argued that even if it did make sense to couple
depowering to more advanced technology, that technology is currently
unknown. That organization stated that it should be apparent that
defining what a ``smart air bag'' is, is not a simple, straightforward
endeavor. According to AAMA, it is premature and highly inappropriate
to consider a sunset date for depowering technologies that are known to
be at least partial solutions to the concerns regarding inflation
related injuries.
AAMA also argued that as manufacturers consider application of
depowered air bag systems, a sunset provision would become a
significant factor in assessing the practicability of design changes.
That organization argued that this will especially be the case for
models with product lives scheduled to end in the period shortly after
the sunset date. According to AAMA, the benefits expected from changes
to depowering for a short period of time, followed by further changes
to meet advanced technology air bag requirements, may not justify the
design/development/certification costs.
AIAM stated that whatever change is made to Standard No. 208, the
basic concept of the revised regulation needs to be permanent. That
organization argued that investments to optimize safety belt/air bag
system designs can only be made if manufacturers know that the barrier
crash test using unbelted dummies will not be reimposed in a short
time. AIAM also argued that the action in this rulemaking should not be
linked to the ``smart'' air bag system rulemaking that NHTSA
contemplates.
IIHS stated that because of uncertainty about the availability and
efficacy of future technology, and because it does not agree that the
proposed regulatory changes will lead to the tradeoffs NHTSA
anticipates--it does not support the inclusion of a sunset provision
for the proposed rule changes. IIHS stated that limiting the duration
of the depowering amendment would be superfluous and counterproductive,
considering the agency anticipates further rulemaking on smart air
bags.
CVC stated that it is concerned by the time frame allowed for
depowered air bags under NHTSA's proposal. That organization stated
that even if NHTSA promptly adopts the sled test, automakers would
still probably not be able to complete the changeover of their fleets
until sometime in model year 1999--and then could be faced with the
prospect of changing their entire fleets back to full-scale crash-
testing soon thereafter. CVC stated that it agrees that smart air-bag
technology holds promise for the future, but there is little reason to
assume that this technology will be sufficiently developed and tested
to permit mass installation just three years from now. CVC argued that
forcing the rapid implementation of new untested technology could
produce a whole new wave of safety concerns (inadvertent, failed or
improper deployment), leading to new occupant injuries and additional
adverse publicity for air bags.
Morton stated that it firmly believes that the depowering amendment
should be temporary. That company stated that the question of duration
cannot be easily answered at this point. It stated its belief that the
suggested approach in the NPRM to specify a several year duration and
to revisit the issue in the context of the rulemaking on smart air bags
is the appropriate option at this point.
General Dynamics stated that it supports the current NHTSA proposed
solutions, but that support is based on NHTSA's statement that
implementation of proposed solutions will be recognized as temporary
measures until ``smart'' solutions
[[Page 12968]]
become available. General Dynamics stated that it disagrees that the
proposed temporary measures will be required for the next several model
years as smart systems are phased in. That company stated that it
believes that the disbenefits of the NHTSA temporary measures will grow
in those years and argues that a near-term mandate for smart air bags
is required.
AirBelt Systems stated that ``either one of the proposed
approaches, due to the adverse safety tradeoffs which it argues will
take place, must be viewed only as an extremely temporary step at
possibly helping to solve the current dilemma of severe injury and
deaths to children from air bags.''
TRW stated that it is concerned that the proposed interim action
could potentially stifle the urgent need for more elegant and
comprehensive solutions that potentially accommodate a much better
balance in protecting children, belted and unbelted occupants, varying
size occupants and varying positioned occupants. TRW stated that,
accordingly, the depowering amendment should be allowed during the
period where an aggressive phase-in schedule exists to develop and
introduce varying degrees of advanced restraint system technologies.
AVS Technologies stated that, if adopted, the sled alternative
should remain in effect for a limited period of time. According to that
company, it should be replaced within two years by a temporary modified
vehicle barrier test.
CFAS stated that if NHTSA accepts manufacturer arguments that
depowered inflators are effective in solving current problems, the
agency must recognize that depowered inflators will involve a
substantial amount of manufacturer resources to design, develop, test
and install on a widespread basis. That organization stated that given
the investment in depowered inflators, manufacturers will be reluctant
to develop new and better technological solutions to improve their air
bag systems. CFAS expressed concern that, consequently, proposals to
alter Standard No. 208 will become permanent, not temporary, and will
work against implementation of smart air bags. CFAS stated that if
NHTSA adopts depowering, it suggests that the agency require
manufacturers to use a dual or multi-staged system, using a
``depowered'' inflator for low speed crashes and a higher-powered
inflator for higher speed crashes.
Public Citizen stated that implementation of a revised Standard No.
208 should supersede this depowering rulemaking as rapidly as possible,
and no later than model year 1999 vehicles. That organization stated
that there should be requirements for dual-or multi-stage inflation air
bags by model year 1999. It stated that, according to comments already
submitted to the agency by air bag suppliers, dual-stage inflation
systems could be installed in model year 1999 vehicles.
After considering the comments, NHTSA has determined that there is
no need to permanently reduce Standard No. 208's performance
requirements to enable manufacturers to fully address the adverse
effects of air bags. This is because there are various alternatives,
albeit with longer technological development and implementation
leadtimes than depowering, that are already allowed by the standard and
that appear likely to result in equal or greater benefits than
depowering without creating adverse safety tradeoffs. Thus, the agency
views depowering as an interim approach, while the vehicle
manufacturers develop and implement better solutions.
One technological alternative is a dual or multiple level inflator,
which has the effect of causing an air bag to perform as a
``depowered'' air bag in low to moderate speed crashes (and possibly in
all crashes in which occupants are belted or the seat is in a forward
position), and as a fully powered air bag to provide protection to
unbelted occupants in higher speed crashes. Thus, dual or multiple
level inflators appear to offer all of the benefits associated with
depowering without the tradeoffs, and may either enable an air bag to
qualify as a smart air bag or be one of the major building blocks of a
smart air bag. The agency observes that several suppliers have
commented that this and/or other technologies are available for
introduction as early as model year 1999. NHTSA believes it is
reasonable to expect the vehicle manufacturers to move rapidly to adopt
such technologies, rather than to continue with single-inflation-level,
depowered air bags.11 The agency also notes that adoption of dual
or multi-level inflators is not inherently dependent on the use of
advanced occupant position sensing devices.
---------------------------------------------------------------------------
\11\ NHTSA notes that concepts such as dual stage inflators are
not new and were considered by the agency in deciding to require
automatic protection. For example, in the early and mid-1970's,
various vehicle manufacturers reported favorable results in testing
the ability of various dual level or variable inflation systems for
air bags to address the problem of out-of-position children. In
1980, NHTSA informed the industry about its analysis of a number of
possible technological solutions, including dual-inflation air bags,
chambering air bags and top-mounted air bags. The July 11, 1984
Final Regulatory Impact Analysis (FRIA) for the 1984 final rule
requiring the installation of automatic occupant restraints in
passenger cars (49 Fed. Reg. 28962; July 17, 1984) listed a variety
of potential technological means for addressing the problem of
injuries associated with air bag deployments (FRIA, pp. III-8 to
10): a dual level inflation system whose operation is based on
impact speed; a dual level inflation system whose operation is based
on a switch in the vehicle seat or elsewhere that measures occupant
size or weight and senses whether an occupant is out of position; a
dual level inflation system whose operation is based on an
electronic proximity detector in the dashboard; and other
technological measures such as bag shape and size, instrument panel
contour, aspiration, and inflation technique.
---------------------------------------------------------------------------
Contrary to AAMA's suggestion, the agency is not assuming that the
current energy level of air bags provides optimum occupant protection,
especially for belted occupants. Instead, the agency recognizes that
more advanced air bag designs can provide appropriate inflation rates
for different levels of crash severity, occupant size/position, and
belted/unbelted conditions. The agency observes that one of the primary
criticisms of current air bags, that they inflate in the same one-size-
fits-all manner regardless of occupant size and position and crash
severity, will also be true for depowered air bags, albeit at a
different level. However, this limitation of current air bag designs,
and the contemplated depowered air bags, can be addressed by the use of
dual or multiple level inflators.
NHTSA also disagrees with IIHS's suggestion that it would be
superfluous to limit the duration of the depowering amendment, since
the agency anticipates further rulemaking on smart air bags and would
likely review all requirements of the standard. While the agency
expects that a variety of test conditions may be added as part of a
rulemaking to require smart air bags, and while the agency has recently
sought public comment on the issue, 62 FR 8917 (February 27, 1997),
based on current belt use rates, there is no reason to assume that the
basic concept of a simple 30 mph barrier test for the unbelted
condition would be dropped. As noted earlier in this notice, about half
of all occupants in potentially fatal crashes still do not wear their
safety belts.12 Moreover, barrier testing is the most prevalent
and accepted means of measuring real world protection.
---------------------------------------------------------------------------
\12\ Even if the use rates were significantly higher, and an
analysis showed that dropping the unbelted test would have net
safety benefits for motor vehicle occupants, the agency could not
drop the test on its own initiative. As the agency noted in its
February 27, 1997 notice, legislation would be necessary to
authorize the agency to take that step.
---------------------------------------------------------------------------
NHTSA recognizes that there is substantial uncertainty as to how
quickly smart air bags can be
[[Page 12969]]
incorporated into the entire fleet. Accordingly, the agency is adopting
the approach suggested in the NPRM of specifying a several-year
duration for the depowering amendment, and will revisit the issue, to
the extent appropriate, in the context of a future rulemaking on smart
air bags.
The agency is specifying a termination date of September 1, 2001,
which roughly corresponds to the beginning of model year 2002. Based on
information provided at NHTSA's February 11-12, 1997 public workshop on
smart air bags, this appears to be a realistic date as to when the
vehicle manufacturers can install some kind of smart air bags
throughout their fleets, or at least more advanced air bags that
provide the benefits associated with depowering without the tradeoffs.
This expiration date assumes that the vehicle manufacturers will use
the discretion they have to rapidly introduce the new air bag
technologies that they and the suppliers have been developing, and will
begin implementation of advanced air bag technologies in many of their
vehicles before that date. For example, several suppliers have stated
that dual or multiple stage inflators are available for introduction
beginning as early as model year 1999, i.e., September 1, 1998, and
that various other advanced air bag technologies will become available
by that time or soon thereafter. NHTSA also believes that allowing
depowering for more than four calendar years should provide
manufacturers a reasonable amount of time to optimize depowered systems
(i.e., tailor venting strategies, etc.), rather than simply depowering
current systems without change. Manufacturers should not, however, read
the September 1, 2001 date as any indication that the agency, in its
smart air bag rulemaking, will not consider a requirement for a phase-
in for smart air bags that begins before that time.
F. Benefits and Trade-Offs
AAMA and IIHS submitted critiques of the analyses of benefits and
trade-offs presented in the PRE, arguing that the agency substantially
overstated the potential disbenefits of depowering. Among other things,
these commenters argued that the agency incorrectly assumed that 30 mph
barrier crash tests represent all fatal highway crashes.
Considerable comment was received on the real world results of the
GM Holden depowered air bag in Australia. AAMA argued that the agency
should have placed greater weight on that information. Several other
commenters suggested that less weight be placed on it. AVS Technologies
stated that if the greater effectiveness of Holden air bags is
primarily attributable to their effectiveness in preventing less severe
injuries (AIS 2), then it is unreasonable to assume that optimizing
U.S. air bags for the belted case will result in the same increased
levels of effectiveness for reducing fatalities. That commenter also
stated that while the PRE states the Holden system is more effective
for serious (MAIS 3+) chest injuries than U.S. air bags, the data show
that the Holden system is considerably less effective than its U.S.
counterpart in reducing MAIS 3+ head injuries. AVS Technologies argued
that, in any event, the figure for Holden effectiveness with respect to
MAIS 3+ injuries is of doubtful validity, given the small number of
cases. Richard Strombotne argued that the number of cases used in the
Holden analysis is so small that the uncertainty in the analysis
renders the results useless. Several commenters noted that Holden air
bags deploy at a higher threshold, and stated that the higher threshold
may account for a large part of the greater effectiveness of Holden air
bags.
The FRE responds to the various comments on benefits and trade-
offs, and presents revised estimates. The estimates presented in the
PRE and FRE for the sled test alternative can be summarized as follows.
The PRE estimated that if current rates of child fatalities were
experienced in an all-air-bag fleet, 128 children would be killed over
the life of a single model year's fleet. The figure of 128 included 38
infants in rear-facing infant seats and 90 older children. Based on
three-and-one-half more months of data showing no new cases of infant
fatalities, but increasing numbers of older child fatalities, the FRE
revises the total number of child fatalities up from 128 to 140. The
new total includes a reduced number (33) of infant fatalities and
increased number (107) of older child fatalities.
NHTSA emphasizes, as it did in the NPRM, that this and the agency's
other rulemaking proceedings and related efforts are intended to ensure
that risks of adverse effects of air bags are reduced so that these
theoretically projected air bag fatalities do not materialize, while
the potential benefits of air bags are retained to the maximum extent
possible.
One area of uncertainty that significantly affects both potential
benefits and tradeoffs is how much the vehicle manufacturers will
depower air bags. AAMA commented that the average level of depowering
will be 20 to 35 percent.
Based on test results and modeling, the FRE estimates that, if 35
percent is the upper end manufacturers adopt for depowering, 47
children would be saved. Using the same assumptions, the FRE estimates
that 34 to 280 fewer teenage and adult passengers may be saved. The FRE
recognizes that, if some air bags are depowered by more than 35
percent, more children would be saved, although there would also be
higher disbenefits. The agency notes that the PRE provided higher
estimates for both potential benefits and disbenefits, primarily
because it assumed greater levels of depowering. 13
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13 Another difference accounting for the revised estimate of
potential disbenefits relates to how the agency used barrier crash
test results for baseline and depowered air bags. In the PRE, the
agency applied the barrier crash test results to all potentially
fatal frontal crashes. AAMA argued that barrier testing only
represents about 10 percent of all fatal crashes, and that
depowering will not have any effect in offset frontal crashes. AAMA
argued that 10 percent of NHTSA's PRE disbenefit estimates would
provide reasonable estimates. AAMA provided no data to show that
there would be no effect of depowering on fatalities in offset
frontal impacts. The agency's analysis indicates that barrier
crashes are closely representative of about 34 percent of all fatal
frontal crashes. The agency agrees that depowering may not have as
much of an effect in offset frontal crashes, but the effect is
unknown. For example, there is still a concern about a greater
chance of an occupant's head hitting the A-pillar in an offset crash
with a depowered air bag. The agency used a range in the FRE,
applying the barrier test results to 34 to 100 percent of all
frontal fatalities, to account for the fact that the agency does not
know if depowering will have a smaller impact in those crashes for
which barrier crashes are less representative.
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Also based on test results and modeling, the FRE estimates that
depowering could save a large portion of the 25 out-of-position drivers
who may be killed by air bags, and four to 22 adult belted passengers.
The first of these figures is unchanged from the PRE; the range for
adult belted passengers is slightly revised. The FRE also estimates
that depowering could save almost all of the seven out-of-position
adult passengers who may be killed by air bags; the PRE did not address
this category. The FRE estimates that 16 to 151 fewer drivers may be
saved.
NHTSA notes that AAMA believes that depowering will result in
higher benefits for unbelted drivers than estimated by the agency. That
organization estimated that depowering could save 215 to 330 small,
out-of-position, unbelted adult drivers. This estimate was based on
estimates of the number of small drivers that would be unbelted,
estimates of the number of crashes in which braking or other factors
would cause those unbelted drivers to be close to the air bag, and test
data by Transport Canada on fifth
[[Page 12970]]
percentile female dummies showing a significant chance of potentially
fatal neck injuries for drivers which are close to the air bag.
The agency observes, however, that AAMA's analysis implies the
occurrence of a much larger number of air bag fatalities than can be
supported by available fatality reports. NHTSA has examined as many low
speed air bag fatality cases as it can find. Based on the cases it
found, NHTSA cannot corroborate the hundreds of air bag fatalities in
low speed crashes implied by AAMA's analysis. Since there are many more
low speed crashes than high speed crashes, and since current air bags
deploy at the same speed in low and high speed impacts, an examination
of high speed crashes would not be likely to reveal a significant
number of additional air-bag-induced fatalities.
As to Holden air bags, the PRE stated that if the relationship in
overall effectiveness of the Holden air bag to U.S. air bags for AIS 2+
injuries is the same for fatalities, an estimated 643 lives of belted
occupants could be saved annually by having depowered air bags like the
Holden air bag. With respect to the comments received concerning this
analysis, the agency recognizes that there are insufficient Holden data
with respect to fatalities to draw conclusions confidently about the
number of lives of belted occupants that would be saved by Holden-type
air bags. Moreover, the agency cannot separate the benefits related to
depowering from the benefits related to the higher deployment
threshold. For these reasons, it would not be appropriate to place
greater weight on the Holden analysis. Nevertheless, the agency still
believes the Holden experience for reducing AIS 2+ injuries indicates
at least the possibility that depowered air bags could significantly
reduce fatalities for belted occupants.
NHTSA notes that, as discussed in the FRE, the agency has assessed
the merits of the comments and accepted some, while rejecting others,
in revising its estimates of the benefits and disbenefits of
depowering. It has rejected comments that chest g's are not the
appropriate way to measure chest injury potential and that chest
deflection or V*C are more appropriate, that the agency based its chest
g's versus risk of injury curve on a minimal number of cadaver
experiments, and that the agency's methodology for estimating benefits
is in error. As mentioned above, the agency partially accepted the
comment that the barrier test might not represent the type of crash
that produces all frontal fatalities. The agency used a range in the
FRE, applying the barrier test results to 34 to 100 percent of all
frontal fatalities, to account for the fact that the agency does not
know if depowering will have a smaller impact in those crashes for
which barrier crashes are less representative. The agency has not
changed its analysis or the presentation of its analysis of the Holden
bag or of the number of adults killed by air bags per year.
Recognizing that there is a great deal of uncertainty concerning
benefits and tradeoffs, NHTSA emphasizes that, in any event, its
decision to permit or facilitate depowering as an interim measure is
driven less by calculations comparing potential benefits and potential
disbenefits than by the need to quickly address the fatalities being
caused by air bags. Further, as discussed above, NHTSA believes that
addressing those fatalities is essential to maintain the public
acceptability of air bags, and thereby ensure that air bags achieve
their full long-term potential in reducing deaths and injuries from
frontal impacts.
Moreover, in the longer run, the use of smart air bag technologies
will enable manufacturers to optimize air bags for a variety of
different conditions, including different crash severities, occupant
sizes and positions, and belted/unbelted conditions. Thus, with the use
of smart air bags, it is possible to both achieve the potential
benefits from using Holden-type air bags and avoid the tradeoffs that
can occur from depowering.
F. Specific Sled Test Requirements/Procedures
1. Neck Injury Criteria
In its January 1997 NPRM, NHTSA proposed to add neck injury
criteria for the 50th percentile male dummy as part of the sled test
alternative. This proposal is consistent with AAMA's request for the
agency to consider injury measurements for the neck in evaluating how
air bags respond to the crash pulse. Specifically, in S13.2, the agency
proposed the following neck injury criteria:
(a) Flexion Bending Moment--190 Nm. SAE Class 600.
(b) Extension Bending Moment--57 Nm. SAE Class 600.
C) Axial Tension--3300 peak N. SAE Class 1000.
(d) Axial Compression--4000 peak N. SAE Class 1000.
(e) Fore-and-Aft Shear--3100 peak N. SAE Class 1000.
The source of the proposed neck injury criteria is
``Anthropomorphic Dummies for Crash and Escape Systems,'' AGARD
Conference Proceedings of NATO, July 1996, AGARD-AR-330. The agency
noted that GM uses the same neck criteria for its injury assessment
reference values (IARV's). Data provided by AAMA indicated that, in
general, these neck criteria could not be met without an air bag. The
agency requested comments on this subject.
Advocates, the American Academy of Pediatrics (AAP), the AORC, AVS,
IIHS, and TRW supported including neck injury criteria. Advocates
stated that such criteria provide valuable minimum criteria for sled
tests and that the criteria especially help evaluate the potential
danger faced by young children who are more susceptible to neck and
spinal injury than adults. AAP stated that such injury criteria will
improve the evaluation and development of occupant protection. IIHS
stated that such criteria are generally desirable in evaluating
occupant protection, but are not critical to maintaining benefits for
unbelted occupants. BMW stated that although it anticipated no problem
with the criteria, it needed time to review them.
Ford, Mitsubishi, and Nissan were concerned about potential
problems with the neck injury criteria. Ford stated that there may be
high variability in the testing for compliance with the criteria,
especially the neck extension criterion. Ford was concerned that there
was insufficient experience with the neck extension criterion to
estimate the repeatability and reproducibility of the neck readings.
Ford and Nissan stated that further data could indicate that adoption
of the injury criteria could unnecessarily limit or delay depowering.
Nevertheless, Ford concluded that it ``does not object to the proposed
neck injury criteria at this time.'' Nissan stated that there was not
sufficient evidence to warrant the adoption of such criteria.
Mitsubishi requested that the agency clarify the technical basis for
the proposed neck injury criteria.
Based on the available information, NHTSA has decided to adopt the
neck injury criteria, as proposed. As AAMA stated in its November 1996
submission, such criteria are necessary to ensure that a vehicle is
equipped with air bags that have protective value, since absent these
criteria, some vehicles could comply with the 125 ms pulse sled test
without air bags. Moreover, compression loads, bending moments, and
tension and shear forces can be significant sources of potential
injuries in crashes. Accordingly, the inclusion of neck injury criteria
should aid in measuring air bag effectiveness and may ultimately
improve crash protection. Though the
[[Page 12971]]
injury criteria are specified for use in testing with the 50th
percentile male dummy, adopting neck injury criteria is consistent with
the agency's goal of protecting children, who are especially
susceptible to neck and spinal injury. NHTSA has developed Nij neck
criteria for children that could be extended to adults. A report
describing this criteria and its development has been docketed. (74-14-
N97)
In the NPRM, NHTSA did not make it clear how the neck injury
measurements would be performed. The agency wishes to clarify that the
neck injury measurement is performed by the six-axis load cell mounted
between the head and upper end of the neck, as specified in 49 CFR
572.33.
In response to Mitsubishi's comment requesting that the agency
clarify the technical basis for the neck injury criteria, the agency
notes that the proposal was based on a request by AAMA to include this
criteria. In the NPRM, the agency explained that the source of the
proposed neck criteria is ``Anthropomorphic Dummies for Crash and
Escape Systems,'' AGARD Conference Proceedings of NATO, July 1996,
AGARD-AR-330. The agency further noted that GM uses the same neck
criteria for its IARVs.
In addition, since the NPRM was issued, NHTSA has docketed two
reports describing a series of agency tests with two vehicle platforms
to evaluate the 125 ms sled pulse recommended by AAMA.
These tests evaluated driver and passenger air bags using a 50th
percentile male dummy and a 5th percentile female dummy. These tests
indicate that an air bag is necessary for a vehicle to comply with the
neck injury criteria. In other words, a vehicle equipped with no air
bag did not comply with the proposed neck injury criteria.
2. Testing Full Vehicles or Partial Vehicles
In the January 1997 NPRM, NHTSA proposed a test procedure similar
to the one presented in AAMA's petition. NHTSA noted that the proposed
procedure specifies that the vehicle, or ``a sufficient portion of the
vehicle to be representative of the vehicle structure,'' is mounted on
the sled. The agency requested comments on the practicality of
conducting sled tests with a whole vehicle, and on whether the quoted
language could be made more objective.
In a letter dated January 24, 1997, NHTSA's Associate Administrator
for Safety Assurance asked several vehicle manufacturers to provide
specific information concerning their experience in conducting sled
tests. Among other things, the agency asked whether there are any
considerations that need to be addressed for using either a full or
partial vehicle on the sled. The agency also asked whether any
manufacturer has ever performed a sled test with a complete or almost
complete vehicle.
AAMA, Subaru, and Volvo stated that manufacturers typically conduct
partial vehicle tests. Nevertheless, AAMA stated that such sled tests
could be conducted on either the full vehicle or partial vehicle.
Similarly, Ford stated that ``audit testing with an entire vehicle on a
sled would be acceptable, even though vehicle manufacturers typically
test with only the passenger compartment or the front portion of the
passenger compartment.'' AVS and Morton stated that it is impracticable
and infeasible to test the entire vehicle on the sled given a vehicle's
weight and size.
Based on its analysis of the available information, NHTSA has
decided to specify testing the entire vehicle. The agency is aware that
sled tests are typically conducted with partial vehicles. However, sled
tests historically have been utilized as pre-manufacture development
tests, rather than as tests for compliance with a Federal safety
standard. The sled tests with partial vehicles could be quickly and
economically set up and repeated. However, the purpose of this standard
is to ascertain the crashworthiness of the final product: the
production vehicle.
The agency's Vehicle Research Test Center (VRTC) has analyzed the
size and power of the equipment used to conduct sled tests. Based on
the available information, the agency believes that the current-design
sled at Transportation Research Center (TRC) can be used to evaluate a
full vehicle's response to a 125 ms pulse. Memoranda in the docket
summarize discussions between agency and General Motors personnel
indicating that the readily available 12 inch diameter cylinder sled is
capable of producing the required acceleration pulse for any complete
vehicle subject to Standard No. 208.
NHTSA believes that a full vehicle test is superior to a partial
vehicle test for the following reasons. A full vehicle test reduces
variability, since a partial vehicle test's outcome could depend on how
a vehicle was cut. In addition, it would be difficult to determine
precisely what a partial vehicle is. Another problem with partial
vehicle testing is how to reinforce it. The agency further notes that a
full vehicle test is more representative of actual crash situations
than a partial vehicle test.
Further, by requiring full vehicle testing, the agency eliminates
the need to define what is meant by a partial vehicle. Accordingly, the
agency's request in the NPRM to define the phrase ``sufficient portion
of vehicle to be representative of the vehicle structure'' is moot.
Ford was concerned that body frame vehicles should not be tested on
a sled test because such vehicles would experience unrealistic
deflection of elastomeric body mounts and local elastic and permanent
deformation of body mounting areas during a sled test if only the frame
were mounted to the sled platform.
NHTSA notes that, if necessary, the frame of a vehicle will be
rigidly attached to the vehicle body during testing such that the
specified acceleration pulse is registered on the vehicle body.
3. Crash Pulse ``Corridor''
In the January 1997 NPRM, NHTSA stated that while AAMA provided
corridors for the original crash pulse in its initial petition, that
organization had not provided corridors for its revised crash pulse.
The agency explained that it contacted AAMA, requesting a figure
showing the mathematical equation for the revised pulse, a graph of the
pulse and corridors for the pulse. The agency stated that it is
necessary to specify corridors in addition to a specific pulse, because
it is generally not possible to duplicate exact pulses. Manufacturers
would be required to assure that their vehicles comply with the
standard's performance requirements for all tests within the specified
corridors. The agency announced that while the proposed regulatory text
specified only a specific crash pulse and not the corridors for that
test, the agency expected to include such corridors in the final rule.
In a January 8, 1997 letter, AAMA provided the agency with a
mathematical equation for the pulse, a nominal pulse curve, and the
allowable upper and lower corridors from which the pulse must not
deviate.
Of the commenters addressing the issue of a crash pulse corridor
pulse, all supported its need. Subaru, Volkswagen, and Volvo stated
that pulse crash corridors should be included. Volkswagen stated that
including corridors is appropriate, since it is impossible to duplicate
a sled pulse trace in a particular test.
NHTSA has decided to include the crash pulse corridors submitted by
AAMA. After reviewing the corridors, VRTC has determined that the
corridors are reasonable and appropriate. The
[[Page 12972]]
agency concludes that corridors, which serve the same purpose as
tolerances, are necessary since it would be difficult to repeat the
exact crash pulse every time a sled test was conducted. Nevertheless,
NHTSA wishes to reiterate that vehicles must be able to comply with the
performance requirements of the Standard in all tests, where the pulse
is within the specified corridors.
4. Air Bag Activation
Two factors must be specified with respect to air bag deployment
during the sled test: when should the timing of the test start, and
when should the air bag be activated? In S13.1 of the proposed
regulatory text, NHTSA stated that ``An inflatable restraint is to be
activated at 25 +/-2 ms after initiation of the acceleration shown in
Figure 6.'' In NHTSA's supplemental letter to vehicle manufacturers,
NHTSA stated that ``The proposed regulatory language in the NPRM states
the air bag will be activated at 25 2 ms after initiation
of the acceleration. Not all manufacturers determine acceleration
initiation the same way. What time zero determinations are used and of
those which one do you recommend?''
AAMA stated that the activation time should be changed to 20
2 ms after the time at which sled acceleration crosses 0.5
g, claiming that this change would provide a more definite test
criterion. Subaru stated that in determining time zero, it uses the
time when the sled acceleration exceeded 1 g as its acceleration
initiation. It believes that this method represents a real crash pulse
considering the proposed air bag firing time of 25 2 ms.
Toyota stated that the agency should define the starting point of the
crash pulse in the sled test. Toyota believed that either t=0 at the
0.5 g level during crash onset or 5 ms before 1 g is reached would be
acceptable. Volvo stated that since not all manufacturers determine
acceleration the same way, the agency should provide a ``methodology to
determine trigger time for the air bag.''
Only Volkswagen commented that the agency should not specify the
activation time. That company stated that specifying the activation
time is design restrictive and could limit ability to depower certain
systems.
NHTSA believes that it is appropriate to specify the activation
time. Except for Volkswagen, all manufacturers submitting comments on
this issue supported such a provision. The agency believes that such a
provision adds precision and objectivity to the test procedure.
NHTSA has decided to adopt the activation time requested by AAMA in
its February 7, 1997 comment; i.e., 20 2 ms after the time
at which the sled acceleration crosses 0.5 g. The agency notes that
this activation time modifies the proposed time only slightly and will
ensure that the air bag activates slightly earlier in the test than the
proposed time. Although the agency does not have specific data to
correlate the difference in performance between a 20 ms activation and
a 25 ms activation, NHTSA believes that the 20 ms activation is more
representative of a typical rigid crash.
5. Test Attitude
In S13.1, NHTSA proposed that the whole or partial vehicle be
mounted on a dynamic test platform ``at the manufacturer's design
attitude, so that the longitudinal center line of the vehicle is
parallel to the direction of the test platform travel and so that
movement between the base of the vehicle and the test platform is
prevented.''
In the supplemental letter to the manufacturers, NHTSA asked how a
manufacturer's test attitude and the vehicle's longitudinal centerline
are measured and what tolerances should be applied to these
measurements.
AAMA stated that the pitch and yaw angles are not particularly
critical and that +/- .5 degrees is sufficient, consistent with SAE
J826 July 95. Ford stated that the test procedure should specify the
manufacturer's nominal vehicle attitude (pitch) for mounting of the
vehicle on the sled, to attain result reproducibility. It stated that
head injury criteria (HIC), neck extension (and possibly other proposed
neck loads) are sensitive to pitch angle of vehicle mounting, because
pitch angle affects the trajectory of the unbelted dummies. Ford
favored the proposal for the tests to be at the ``manufacturer's design
attitude.'' Ford opposed setting the vehicle's pitch on the sled to
match that of the particular vehicle that is purchased when loaded to
test weight. It believed that approach would reduce the test's
reproducibility. Subaru stated that it mounts the partial vehicle
parallel to the direction of the test platform travel for its testing.
It stated although it had no problems related to improper alignment,
clear regulatory tolerances would be helpful.
Based on previous test experience and on the available information,
NHTSA has decided to incorporate the same test conditions already set
forth in S8 14 into the sled test specified in S13. With respect
to the vehicle test attitude, the agency has decided to add a provision
in S13.3 that is patterned after S8.1.1(d). The agency believes that
this provision addresses the concerns of the commenters without
unnecessarily complicating the test conditions. The agency believes
that requiring the attitude of the vehicle on the sled to be at any
alignment between the attitude in the ``as delivered'' condition and
the attitude in the ``fully loaded condition'' will eliminate
difficulties that have been caused by differences between the
theoretical fiduciary marks on blue prints and the actual assembly of
the vehicle. The agency further notes that the loading represents a
real world range of attitudes that the restraint system should be able
to handle.
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14 S8 specifies test conditions for vehicle loading, fuel
system capacity, vehicle test attitude, seat location, and the
status of doors and windows. The provision for vehicle test attitude
references the ``as delivered condition.''
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6. Completion of Sled Test
Ford stated that the sled test should be considered completed as
soon as the sled brakes are applied. It claimed that dummy rebound
kinematics and instrumentation readings are not representative of a
highway collision during the braking deceleration phase of sled test.
Ford is correct that dummy measurement recorded during the rebound
phase will not be considered by this provision because sled braking is
not regulated by the standard. The agency notes that it would be
inappropriate to reference a brake application point because sled
braking varies depending on the type of sled.
G. Miscellaneous Issues.
1. Multistage Manufacturer Certification
The Recreational Vehicle Industry Association (RVIA) and Atwood
Mobile Products (a seat manufacturer that supplies seats for conversion
vehicles) requested a delay in the effective date for conversion
vehicle manufacturers. RVIA requested a one-year delay in the
compliance date for certification of vehicles manufactured in more than
one stage. That organization stated that any changes to air bag power
may mean that recertification will be necessary.
NHTSA has decided not to differentiate the effective date of
today's final rule based on whether the vehicle is manufactured in
multiple stages. The agency notes that today's amendment imposes no new
requirements or costs, but instead permits or facilitates depowering of
current air bags.
[[Page 12973]]
2. Effective Date
In the NPRM, NHTSA requested comments on whether the amendment
should take effect immediately upon publication based on the fact that
it addresses an urgent safety problem, the death of young children. The
agency stated that the proposed amendment would permit or facilitate
the immediate depowering of air bags, thereby helping to reduce child
fatalities caused by air bags. The agency also noted that the proposed
amendment would not impose any new requirements, but instead would
provide additional flexibility to manufacturers in addressing this
problem.
AAMA, Ford, Advocates, and IIHS favored adopting the amendments
immediately. AAMA strongly advocated having the amendment take effect
immediately. That organization stated that ``Depowering is the most
immediate and effective technical means of addressing the issues that
have been raised. The amendment allowing depowering should be effective
upon the date of publication of the final rule.'' Ford stated that the
agency should quickly issue the final rule so that depowered bags can
be available on model year 1998 cars. Advocates stated that it is in
the public interest to dispense with the 30-day waiting period that is
customarily required prior to a rule taking effect.
Based on the available information, NHTSA has decided to make the
amendment effective on the date of publication. The agency believes
that there is good cause to have an immediate effective date, given
that an immediate effective date is necessary to enable vehicle
manufacturers to begin depowering air bags, and thus begin saving
lives, as soon as possible. As the agency noted in the NPRM, the
amendment will not impose any new requirements, but instead provides
additional flexibility to manufacturers in addressing this problem.
VI. Rulemaking Analyses and Notices
A. Executive Order 12866 and DOT Regulatory Policies and Procedures
NHTSA has considered the impact of this rulemaking action under
Executive Order 12866 and the Department of Transportation's regulatory
policies and procedures. This rulemaking document was reviewed by the
Office of Management and Budget under E.O. 12866, ``Regulatory Planning
and Review.'' This action has been determined to be ``significant''
under the Department of Transportation's regulatory policies and
procedures. The action is considered significant because of the degree
of public interest in this subject.
This rule has been designated by OMB as a major rule under Chapter
8 of Title 5, U.S. Code. NHTSA has determined, however, that there is
good cause for making this rule effective less than 60 days after
submission of the rule to each House of Congress and to the Comptroller
General because a delay in implementing this rule would be contrary to
the public interest. In response to the agency's specific request for
comments on an immediate effective date, representatives of the
automobile and insurance industries as well as a leading public
interest group expressed support. No opposing comments were received.
Making this rule effective immediately is necessary to enable the
manufacturers to begin depowering efforts, and thus begin saving lives,
as soon as possible.
The final rule does not impose any new requirements or costs, but
instead permits or facilitates approximately 20 to 35 percent
depowering of current air bags. Any cost difference between baseline
and depowered air bags is negligible.
A full discussion of costs and benefits can be found in the
agency's regulatory evaluation for this rulemaking action, which is
being placed in the docket.
B. Regulatory Flexibility Act
In the NPRM, NHTSA stated that after considering the effects of
this rulemaking action under the Regulatory Flexibility Act (5 U.S.C.
601 et seq.), it certified that the proposed amendment would not have a
significant economic impact on a substantial number of small entities.
NHTSA noted that the cost of new passenger cars or light trucks would
not be affected by the proposed amendment. Under 5 U.S.C. 605(b), NHTSA
stated that the proposed amendment would primarily affect passenger car
and light truck manufacturers and manufacturers of air bags which are
not small entities. The agency referenced the Small Business
Administration's regulations at 13 CFR Part 121 which define a small
business, in part, as a business entity ``which operates primarily
within the United States.'' (13 CFR 121.105(a)).
In the NPRM, the agency estimated that there are at most five small
manufacturers of passenger cars in the U.S., producing a combined total
of at most 500 cars each year. The agency stated that it does not
believe small businesses manufacture even 0.1 percent of total U.S.
passenger car and light truck production each year. The Coalition of
Small Volume Automobile Manufacturers (COSVAM) stated that ``the five
U.S.-based small manufacturers acknowledged by NHTSA'' are
significantly affected by NHTSA's rules, and that it would be improper
to fail to consider the effects on these five companies. In addition,
COSVAM stated that NHTSA's regulations affect an even greater number of
small foreign auto manufacturers that import into the U.S. That
organization stated that it would be inappropriate to disregard the
rulemaking's effect on such entities.
NHTSA again notes that today's final rule will not impose any new
requirements or costs on vehicle manufacturers, but instead will permit
or facilitate approximately 20 to 35 percent depowering of current air
bags. Therefore, no vehicle manufacturer, regardless of its size, will
be required to take any action as a result of the rule. Accordingly,
the agency believes that the rule will have no significant impact on
small vehicle manufacturers.
C. National Environmental Policy Act
NHTSA has analyzed this final rule for the purposes of the National
Environmental Policy Act and determined that it will not have any
significant impact on the quality of the human environment.
D. Executive Order 12612 (Federalism) and Unfunded Mandates Act.
The agency has analyzed this final rule in accordance with the
principles and criteria set forth in Executive Order 12612. NHTSA has
determined that the amendment does not have sufficient federalism
implications to warrant the preparation of a Federalism Assessment.
In issuing this amendment to permit or facilitate depowering, the
agency notes, for the purposes of the Unfunded Mandates Act, that is
pursuing the least cost alternative. As noted above, any cost
difference between current and depowered air bags is negligible. This
alternative was selected by NHTSA because depowering would prevent many
of the air bag-related fatalities that have been occurring and can be
implemented more quickly than the other alternatives. Further,
depowering is the measure that industry itself has been recommending as
a means for preventing those fatalities.
E. Civil Justice Reform
This proposed amendment does not have any retroactive effect. Under
49 U.S.C. 30103, whenever a Federal motor vehicle safety standard is in
effect, a State may not adopt or maintain a safety standard applicable
to the same aspect of performance which is not identical to the Federal
standard, except to the
[[Page 12974]]
extent that the state requirement imposes a higher level of performance
and applies only to vehicles procured for the State's use. 49 U.S.C.
30161 sets forth a procedure for judicial review of final rules
establishing, amending or revoking Federal motor vehicle safety
standards. That section does not require submission of a petition for
reconsideration or other administrative proceedings before parties may
file suit in court.
List of Subjects in 49 CFR Part 571
Imports, Incorporation by reference, Motor vehicle safety, Motor
vehicles, Rubber and rubber products, Tires.
In consideration of the foregoing, 49 CFR Part 571 is amended as
follows:
PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS
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.
2. Section 571.208 is amended by revising S3 and S8.1, and by
adding S13 through S13.4, to read as follows:
Sec. 571.208 Standard No. 208, Occupant crash protection.
* * * * *
S3. Application. This standard applies to passenger cars,
multipurpose passenger vehicles, trucks, and buses. In addition, S9,
Pressure vessels and explosive devices, applies to vessels designed to
contain a pressurized fluid or gas, and to explosive devices, for use
in the above types of motor vehicles as part of a system designed to
provide protection to occupants in the event of a crash.
Notwithstanding any language to the contrary, any vehicle manufactured
after March 19, 1997 and before September 1, 2001 that is subject to a
dynamic crash test requirement conducted with unbelted dummies may meet
the requirements specified in S13 instead of the applicable unbelted
requirement.
* * * * *
S8.1 General conditions. The following conditions apply to the
frontal, lateral, and rollover tests. Except for S8.1.1(d), the
following conditions apply to the alternative unbelted sled test set
forth in S13 from March 19, 1997 until September 1, 2001.
* * * * *
S13 Alternative unbelted test for vehicles manufactured before
September 1, 2001.
S13.1 Instrumentation Impact Test--Part 1--Electronic
Instrumentation. Under the applicable conditions of S8, mount the
vehicle on a dynamic test platform at the vehicle attitude set forth in
S13.3, so that the longitudinal center line of the vehicle is parallel
to the direction of the test platform travel and so that movement
between the base of the vehicle and the test platform is prevented. The
test platform is instrumented with an accelerometer and data processing
system having a frequency response of 60 channel class as specified in
Society of Automotive Engineers (SAE) Recommended Practice J211/1 MAR
95, Instrumentation for Impact Test--Part 1--Electronic
Instrumentation. SAE J211/1 MAR 95 is incorporated by reference and
thereby is made part of this standard. The Director of the Federal
Register approved the material incorporated by reference in accordance
with 5 U.S.C. 552(a) and 1 CFR part 51. A copy may be obtained from SAE
at Society of Automotive Engineers, Inc., 400 Commonwealth Drive,
Warrendale, PA 15096. A copy of the material may be inspected at
NHTSA's Docket Section, 400 Seventh Street, S.W., room 5109,
Washington, DC, or at the Office of the Federal Register, 800 North
Capitol Street, N.W., Suite 700, Washington, DC. The accelerometer
sensitive axis is parallel to the direction of test platform travel.
The test is conducted at a velocity change approximating 30 mph with
acceleration of the test platform such that all points on the crash
pulse curve within the corridor identified in Figure 6 are covered. An
inflatable restraint is to be activated at 20 ms +/-2 ms from the time
that 0.5 g is measured on the dynamic test platform. The test dummy
specified in S8.1.8.2, placed in each front outboard designated seating
position as specified in S11, shall meet the injury criteria of S6.1,
S6.2, S6.3, S6.4, S6.5, and S13.2 of this standard.
13.2 Neck injury criteria. A vehicle certified to this alternative
test requirement shall, in addition to meeting the criteria specified
in S13.1, meet the following injury criteria for the neck, measured
with the six axis load cell (ref. Denton drawing C-1709) that is
mounted between the bottom of the skull and the top of the neck as
shown in drawing 78051-218, in the unbelted sled test:
(a) Flexion Bending Moment--190 Nm. SAE Class 600.
(b) Extension Bending Moment--57 Nm. SAE Class 600.
(c) Axial Tension--3300 peak N. SAE Class 1000.
(d) Axial Compression--4000 peak N. SAE Class 1000.
(e) Fore-and-Aft Shear--3100 peak N. SAE Class 1000.
13.3 Vehicle test attitude. When the vehicle is in its ``as
delivered'' condition, measure the angle between the driver's door sill
and the horizontal. Mark where the angle is taken on the door sill. The
``as delivered'' condition is the vehicle as received at the test site,
with 100 percent of all fluid capacities and all tires inflated to the
manufacturer's specifications as listed on the vehicle's tire placard.
When the vehicle is in its ``fully loaded'' condition, measure the
angle between the driver's door sill and the horizontal, at the same
place the ``as delivered'' angle was measured. The ``fully loaded''
condition is the test vehicle loaded in accordance with S8.1.1(a) or
(b) of Standard No. 208, as applicable. The load placed in the cargo
area shall be centered over the longitudinal centerline of the vehicle.
The pretest door sill angle, when the vehicle is on the sled, (measured
at the same location as the as delivered and fully loaded condition)
shall be equal to or between the as delivered and fully loaded door
sill angle measurements.
13.4 Tires and wheels. Remove the tires and wheels.
3. Section 571.208 is amended by adding Figure 6 at the end of the
section to read as follows:
BILLING CODE 4910-59-P
[[Page 12975]]
[GRAPHIC] [TIFF OMITTED] TR19MR97.009
Issued on: March 14, 1997.
Ricardo Martinez,
Administrator.
[FR Doc. 97-6954 Filed 3-14-97; 3:42 pm]
BILLING CODE 4910-59-C
