[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 <a href="http://
www.nhtsa.dot.gov">http://
www.nhtsa.dot.gov</a> 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).<SUP>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.<SUP>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.<SUP>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.<SUP>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 <SUP>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

    <bullet> 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.
    <bullet> 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.
    <bullet> 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.
    <bullet> 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

    <bullet> 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.<SUP>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:
    <bullet> 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.
    <bullet> Information and supporting data for the specific sled 
pulse recommended by AAMA.
    <bullet> Analysis comparing the potential benefits and net effects 
on safety of the two proposed alternatives.
    <bullet> 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.
    <bullet> 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.
    <bullet> 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.<SUP>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).<SUP>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.
---------------------------------------------------------------------------

    \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.<SUP>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 <SUP>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.
---------------------------------------------------------------------------

     <SUP>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.<SUP>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.<SUP>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. <SUP>13
---------------------------------------------------------------------------

     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.
---------------------------------------------------------------------------

    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 <plus-minus> 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 
<plus-minus> 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 <plus-minus> 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 <plus-minus> 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 <SUP>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.
---------------------------------------------------------------------------

     <SUP>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.''
---------------------------------------------------------------------------

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:

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[[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