Federal Motor Vehicle Safety Standards; Occupant Crash Protection

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.

-----------------------------------------------------------------------

SUMMARY: NHTSA is temporarily amending the agency's occupant crash

protection standard to ensure that vehicle manufacturers can quickly

depower all air bags so that they inflate less aggressively. The agency

is taking this action to provide an immediate, but interim, solution to

the problem of the fatalities and injuries that current air bag designs

are causing in relatively low speed crashes to small, but growing

numbers of children, and occasionally to adult occupants.

DATES: Effective Date: The amendments made in this rule are effective

March 19, 1997.

Incorporation by reference. The incorporation by reference of a

publication listed in the regulation is approved by the Director of the

Federal Register as of March 19, 1997.

Petitions: Petitions for reconsideration must be received by May 5,

1997.

ADDRESSES: Petitions for reconsideration should refer to the docket and

notice number of this notice and be submitted to: Administrator,

National Highway Traffic Safety Administration, 400 Seventh Street, SW,

Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: For information about air bags and

related rulemakings: Visit the NHTSA web site at http://

www.nhtsa.dot.gov and select ``AIR BAGS: Information about air bags.''

For non-legal issues: Mr. Clarke Harper, Chief, Light Duty Vehicle

Division, NPS-11, National Highway Traffic Safety Administration, 400

Seventh Street, SW, Washington, DC 20590. Telephone: (202) 366-2264.

Fax: (202) 366-4329.

For legal issues: J. Edward Glancy, Office of Chief Counsel, NCC-

20, National Highway Traffic Safety Administration, 400 Seventh Street,

SW, Washington, DC 20590. Telephone: (202) 366-2992. Fax: (202) 366-

3820.

SUPPLEMENTARY INFORMATION:

Table of Contents

I. Background.

A. Air Bags: Safety Issues.

B. Current Requirements for Air Bags.

II. Overview and Summary.

III. January 1997 Depowering Proposal.

IV. Summary of Comments.

V. Agency Decision.

A. Should NHTSA amend Standard No. 208 to permit/facilitate

depowering?

B. 80 g's chest injury criterion vs. sled test.

C. Application of the amendment to driver air bags.

D. Duration of amendment.

E. Benefits and trade-offs.

F. Specific sled test requirements/procedures.

1. Neck injury criteria.

2. Testing whole vehicles or partial vehicles.

3. ``Corridor'' for crash pulse.

4. Air bag activation.

5. Test attitude.

6. Completion of sled test.

G. Miscellaneous Issues.

1. Multistage manufacturer certification.

2. Effective date.

VI. Rulemaking Analyses and Notices.

I. Background

A. Air Bags: Safety Issues

Air bags have proven to be highly effective in reducing fatalities

from frontal crashes, the most prevalent fatality and injury-causing

type of crash. Those crashes result in 64 percent of all driver and

right-front passenger fatalities.

NHTSA estimates that, between 1986 and February 15, 1997, air bags

have saved 1,828 drivers and passengers (1,639 drivers and 189

passengers). Based on current levels of effectiveness, air bags will

save more than 3,000 lives each year in passenger cars and light trucks

when all light vehicles on the road are equipped with dual air bags.

This is based on current safety belt use rates (about 68 percent,

according to State-reported surveys).1 Using this assumption, more

than two-thirds of the persons saved would be persons not using any

type of safety belt.

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

At the same time, air bags are causing fatalities in some

situations, especially to children. As of February 15, 1997, NHTSA's

Special Crash Investigation program had identified 38 crashes in this

country in which the deployment of the passenger air bag resulted in

fatal injuries to a child. Two adult passengers have also been fatally

injured. On the

[[Page 12961]]

driver side, 21 drivers are known to have been fatally injured.2

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

The fatalities involving children have a number of fairly

consistent characteristics. First, as to restraint usage, the infants

are in rear-facing infant restraints. The older children are generally

not using any type of restraint. Second, the crashes in which the

infants and older children were fatally injured occurred at relatively

low speeds. Third, the fatally injured infants and older children were

very close to the dashboard when the air bag deployed. Rear-facing

child seats are very close to the dashboard in a crash, even in the

absence of pre-impact braking. As to almost all of the older children,

the non-use or improper use of safety belts in conjunction with pre-

impact braking resulted in the forward movement of the children such

that they were very close to the air bag when it deployed. Because of

this proximity, the children appear to have sustained fatal head or

neck injuries from the deploying passenger air bag.

NHTSA notes that driver fatalities are very rare in comparison to

the number of vehicles equipped with driver air bags (more than 56

million vehicles, through model year 1996), and to the number of

drivers saved by air bags. The data for drivers suggest that two groups

of drivers are more at risk than other drivers from a driver air bag.

One group is older drivers. However, the agency notes that, primarily

due to their relative frailty, older drivers are more at risk than

younger drivers under a wide range of crash circumstances, regardless

of whether the older drivers use safety belts and regardless of whether

they drive vehicles equipped with air bags.

The other group of drivers is short-statured adults. Drivers five

feet two inches or shorter comprise 10 of the 21 driver fatalities the

agency is aware of to date. However, NHTSA is not aware of any

inflation-induced fatality in the United States of a female driver 5

feet 2 inches or shorter in an air bag deployment since November 1995,

16 months ago.3

---------------------------------------------------------------------------

\3\ A fatality involving a 5 feet 4 inch female driver did occur

in October 1996.

---------------------------------------------------------------------------

As in the case of the children fatally injured by air bags, the key

factor regarding the fatally injured adults has been their proximity to

the air bag when it deployed. The most common reason for their

proximity was failure to use safety belts. Only six of the 21 drivers

were known to be restrained by lap and shoulder belts at the time of

the crash. Moreover, of those six, two appeared to be out of position

(slumped over the wheel due to medical conditions).

B. Current Requirements for Air Bags

Under Chapter 301 of Title 49, U.S. Code (''Motor Vehicle

Safety''), NHTSA is authorized to set Federal motor vehicle safety

standards applicable to the manufacture and sale of new motor vehicles

and new motor vehicle equipment. Standard No. 208, Occupant Crash

Protection, one of the original Federal motor vehicle safety standards

issued under this statute, has long required motor vehicle

manufacturers to install safety belts to protect occupants during a

crash. Beginning in the late 1980's, the standard has required

manufacturers to provide automatic protection for frontal crashes,

i.e., protection that requires no action by the occupant.

In establishing Standard No. 208's current automatic protection

requirements for passenger cars in 1984, and later extending those

requirements to light trucks, NHTSA expressly permitted a variety of

methods of providing automatic protection, including automatic belts

and air bags. However, the agency included a number of provisions to

encourage manufacturers to install air bags. These included extra

credit during the standard's phase-in period for vehicles using air

bags and allowing vehicles with a driver air bag system to count, for a

limited period of time, as a vehicle meeting the standard's automatic

protection requirements for both driver and right-front passenger

positions.

Ultimately, however, consumer demand led to the installation of air

bags throughout the new car fleet. By the beginning of this decade,

manufacturers were rapidly moving to install air bags in all of their

passenger cars and light trucks.

Congress included a provision in the Intermodal Surface

Transportation Efficiency Act of 1991 (ISTEA) directing NHTSA to amend

Standard No. 208 to require that all passenger cars and light trucks

provide automatic protection by means of air bags. The Act required at

least 95 percent of each manufacturer's passenger cars manufactured on

or after September 1, 1996 and before September 1, 1997 to be equipped

with an air bag and a manual lap/shoulder belt at both the driver and

right front passenger seating positions. Every passenger car

manufactured on or after September 1, 1997 must be so equipped. The

same basic requirements are phased-in for light trucks one year

later.4 The final rule implementing this provision of ISTEA was

published in the Federal Register (58 FR 46551) on September 2, 1993.

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

Standard No. 208's automatic protection requirements, whether for

air bags or (until the provisions of ISTEA fully take effect) for

automatic belts, are performance requirements. The standard does not

specify the design of an air bag. Instead, vehicles must meet specified

injury criteria, including criteria for the head and chest, measured on

test dummies, during a barrier crash test, at speeds up to 30 mph.

These criteria must be met for air bag-equipped vehicles both when the

dummies are belted and when they are unbelted. The latter test

condition ensures that a vehicle provides ``automatic protection,''

i.e., protection by means that require no action by vehicle occupants.

These requirements apply to the performance of the vehicle as a

whole, and not to the air bag as a separate item of motor vehicle

equipment. This approach permits vehicle manufacturers to ``tune'' the

performance of the air bag to the crash pulse 5 and other specific

attributes of each of their vehicles. Further, it leaves them free to

select specific attributes for their air bags, such as dimensions and

actuation time.

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

II. Overview and Summary

NHTSA is implementing a comprehensive plan of rulemaking and other

actions (e.g., consumer education and encouragement of primary

enforcement of State safety belt use laws) addressing the adverse

effects of air bags. The rulemaking actions which have been taken, or

are being taken, include the following:

Interim Rulemaking Solutions

In this notice, NHTSA is temporarily amending Standard No.

208, to ensure that vehicle manufacturers can depower all air bags

[[Page 12962]]

so that they inflate less aggressively. This change, coupled with the

considerable flexibility already provided by the standard's existing

performance requirements, will provide the vehicle manufacturers

maximum flexibility to quickly address the adverse effects of current

air bags.

On November 27, 1996, the agency published in the Federal

Register (61 FR 60206) a final rule amending Standards No. 208 and No.

213 to require improved labeling on new vehicles and child restraints

to better ensure that drivers and other occupants are aware of the

dangers posed by passenger air bags to children, particularly to

children in rear-facing infant restraints in vehicles with operational

passenger air bags. The new labels were required on vehicles beginning

February 25, 1997, and are required on child restraints, beginning May

27, 1997.

On January 6, 1997, the agency published in the Federal

Register (62 FR 798) a final rule extending until September 1, 2000, a

provision in Standard No. 208 permitting vehicle manufacturers to offer

manual cutoff switches for the passenger air bag for new vehicles

without rear seats or with rear seats that are too small to accommodate

rear-facing infant restraints.

On January 6, 1997, the agency published in the Federal

Register (62 FR 831) an NPRM to permit motor vehicle dealers and repair

businesses to deactivate, upon the request of consumers, driver and

passenger air bags. The agency expects to announce a final decision on

this issue shortly.

Longer Term Rulemaking Solution

NHTSA plans to issue an NPRM to require a phasing-in of

smart air bags and to establish performance requirements for those air

bags. On February 11 and 12, 1997, the agency held a public technical

workshop to discuss appropriate test procedures and other issues

related to that forthcoming proposal. Among other things, the agency

may propose using a 5th percentile female dummy and specifying

appropriate injury criteria for that dummy, including neck injury.

In addition to these actions, the agency is participating with

automobile manufacturers, air bag suppliers, insurance companies and

safety organizations in a coalition effort to address the adverse

effects of air bags by increasing the use of safety belts and child

seats. Substantial benefits could be obtained from achieving higher

safety belt use rates. For example, if observed belt use increased from

68 percent to 80 percent, an additional 2,900 lives would be saved

annually over the 9,529 lives currently being saved by safety belts.

The coalition has a three-point program that seeks to educate the

public about safety belt and child seat use, work with state and local

officials to improve enforcement of safety belt and child seat use

laws, and seek the enactment of ``primary'' safety belt use laws.6

---------------------------------------------------------------------------

\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.

---------------------------------------------------------------------------

A 1995 NHTSA analysis of Fatal Analysis Reporting System (FARS)

data on restraint use among fatally injured motor vehicle occupants

from 1983 to 1994 indicates that primary enforcement is the most

important aspect of a safety belt use law affecting the rate of safety

belt use. For virtually all states with a primary enforcement law,

statistically significant increases associated with the presence of

such a law were detected using several different methods. The analysis

suggests that the increase in use rates attributable to the enactment

of a primary enforcement law is at least 15 percentage points. This

increase in safety belt use translates into a 5.9 percent decline in

fatalities in a state that authorizes primary enforcement of the law.

In California and Louisiana, states which recently upgraded their laws

to allow for primary enforcement, safety belt usage increased by 13 and

17 percentage points, respectively.

III. January 1997 Depowering Proposal

On January 6, 1997, NHTSA published an NPRM (62 FR 807) to

temporarily amend Standard No. 208 to help reduce the fatalities and

injuries that current air bags are causing in relatively low speed

crashes to small, but growing numbers of children, and occasionally to

adults.

The agency believed that the proposed amendments would ensure that

vehicle manufacturers can quickly depower all air bags so that they

inflate less quickly and less aggressively. Based on agency research

and analysis regarding the optimal range of air bag depowering, the

agency tentatively concluded that an average depowering of 20 to 35

percent would reduce the risk of air bag fatalities in low speed

crashes, while substantially preserving the life-saving capabilities of

air bags in higher speed crashes.

NHTSA proposed adopting either, or both, of two different

approaches that would permit or facilitate an approximate 20 to 35

percent average depowering of current air bags. One approach was to

temporarily make it easier to meet the chest acceleration requirement

that an unbelted dummy must meet in a crash test at speeds up to 30

mph, by raising the limit from 60 g's to 80 g's. The other approach,

which appeared to allow higher levels of depowering, was to temporarily

replace vehicle crash testing using an unbelted dummy with the American

Automobile Manufacturers Association's (AAMA's) modified ``sled test''

protocol incorporating a 125 millisecond (msec) standardized crash

pulse and also using an unbelted dummy.

NHTSA recognized that while depowered air bags would provide

immediate benefits in a number of situations, they would not fully

solve the problem of adverse effects from air bags and could also

reduce protection to unbelted occupants in higher speed crashes. NHTSA

indicated that it believes the ultimate solution to the problem of

adverse effects from air bags is implementation of more advanced air

bags that adjust the deployment decision/inflation rate based on such

factors as size and position of vehicle occupants, severity of crash,

and whether safety belts are being used. The agency therefore stated in

the NPRM that it viewed depowering as an interim measure to be used

until better solutions can be implemented.

In its Preliminary Regulatory Evaluation (PRE), the agency

presented several methodologies to analyze the potential benefits and

net effects on safety associated with depowering. Two methodologies

utilized research testing and mathematical modeling results to examine

the effect of depowering on chest g's and then to estimate the effect

of chest g changes on fatalities. A third methodology examined the

experience in Australia of a General Motors-designed Holden car, which

has less aggressive air bags.

NHTSA requested commenters to provide additional information in a

number of areas, including the following:

Information and data to help the agency refine its

estimates (presented in the PRE) of the potential benefits and net

effects on safety that would be likely to result from depowering.

Information and supporting data for the specific sled

pulse recommended by AAMA.

Analysis comparing the potential benefits and net effects

on safety of the two proposed alternatives.

Information concerning the extent of the existing problem

of driver fatalities and injuries from air bags and

[[Page 12963]]

the extent to which manufacturers have already addressed the problem by

design changes to driver air bags.

Whether the same or different requirements should apply to

the passenger and driver positions, including the advisability of

limiting the proposed temporary amendment to passenger air bags only.

The appropriate duration of the temporary amendment.

IV. Summary of Comments

NHTSA received over 160 comments in response to the NPRM.

Commenters included vehicle manufacturers, air bag and component

manufacturers, safety advocacy groups, insurance groups, trade

associations, State entities, and individuals.

Most commenters agreed that the agency should issue requirements to

facilitate air bag depowering, thereby reducing injury risks related to

air bag deployment in low speed crashes. Support for depowering came

from commenters such as Advocates for Highway and Auto Safety

(Advocates), the American Automobile Manufacturers Association (AAMA),

the Association of International Automobile Manufacturers (AIAM), the

National Transportation Safety Board (NTSB), the Insurance Institute

for Highway Safety (IIHS), specific vehicle manufacturers, and the

Automotive Occupant Restraints Council (AORC). These commenters stated

that depowered air bags will improve vehicle safety by reducing the

risk posed to vehicle occupants. While the vehicle manufacturers

favored allowing depowering indefinitely, Public Citizen, Advocates,

and air bag manufacturers conditioned their support on the placing of a

time limit on depowering.

The Center for Auto Safety (CFAS), the Parents Coalition for Air

Bag Warnings, and some individuals opposed depowering. These commenters

argued that switching from a crash test to sled test with a generic,

large car crash pulse would result in an unreasonably lenient standard

that would result in a substantial increase in adult deaths.

Commenters addressed specific issues raised in the NPRM, including

whether to adopt the 80g's alternative, the sled test alternative, or

both; whether to depower both driver side and passenger side air bags;

whether to make the amendment temporary or permanent; and the

appropriateness of the agency's estimates of potential benefits and

tradeoffs in the PRE. Commenters also addressed specific issues

involving the sled test requirements and test conditions, including the

neck injury criteria, testing a portion of the vehicle or the entire

vehicle, the ``corridor'' for the crash pulse, the activation time for

the air bag during the sled test, and the vehicle test attitude.

Commenters, especially the safety groups, addressed various issues that

are not directly related to depowering, such as adopting minimum

deployment speed thresholds and undertaking a comprehensive upgrade of

Standard No. 208. A more specific discussion of the comments, and the

agency's responses, are set forth below.

V. Agency Decision

After carefully considering the comments, NHTSA has decided to

adopt AAMA's modified unbelted sled test protocol as a temporary

alternative to Standard No. 208's current unbelted crash test

requirement. This change, coupled with the considerable flexibility

already provided by the standard's performance requirements, will

provide the vehicle manufacturers with maximum flexibility to quickly

address and mitigate the adverse effects of current air bags.

A. Should NHTSA Amend Standard No. 208 To Permit/Facilitate Depowering?

As discussed above, NHTSA proposed to amend Standard No. 208 to

ensure that vehicle manufacturers can depower all air bags so that they

inflate less aggressively. The vast majority of commenters supported

depowering as a quick way of addressing the problem of adverse effects

of air bags. Commenters supporting depowering were diverse and included

AAMA and AIAM, representing essentially all domestic and import vehicle

manufacturers, AORC, representing suppliers, IIHS, Advocates, and

Public Citizen.

A few commenters, however, opposed depowering or otherwise raised

concerns about the basic approach of the agency's proposal. The issues

raised by those commenters are addressed in this section. Comments

concerning how depowering should be accomplished, e.g., what

alternative amendment should be adopted, whether the driver side should

be included, and the appropriate duration for the amendment, will be

discussed in later sections.

The Parent's Coalition recommended that NHTSA consider issuing a

final rule mandating on-off switches for air bags and a higher minimum

deployment threshold (for single level inflator air bags) in lieu of

amending Standard No. 208 to permit depowering. That organization

stated that information from NHTSA's Special Crash Investigation

Program shows that low deployment thresholds are the central cause of

air bag deaths and injuries, and that the agency erred in not including

an increased deployment threshold as part of its proposal. The Parent's

Coalition expressed concern that the contemplated level of depowering

will not save all children, and will result in an increase, perhaps a

substantial one, in adult deaths and injuries. The Parent's Coalition

stated that the increase in adult deaths from depowering appears to be

an unacceptable cost in exchange for the relatively modest reduction in

child deaths, especially since the child deaths could be prevented,

without such adverse tradeoffs, by an on-off switch and by an increase

in deployment threshold.

CFAS also urged NHTSA to look at whether a moderate increase in

deployment threshold would perform a better job of increasing vehicle

safety, before adopting the depowering proposal. CFAS also stated that

the issue before NHTSA is not whether depowered inflators should be

permitted under Standard No. 208, but whether manufacturers should be

permitted to escape responsibility for meeting the current injury

criteria of the standard. CFAS stated that Standard No. 208 does not

prohibit manufacturers from using depowered inflators.

While it did not oppose depowering as an interim measure, Consumers

Union stated that the most important step that the agency can take in

the near term to address the situation is to establish a higher

deployment threshold, on an expedited basis, a requirement for a low-

end limit to the vehicle impact level barrier equivalent velocity,

below which air bags will not be triggered to inflate.

NHTSA notes that, in its January 1997 proposal, it discussed a

variety of alternative approaches for addressing the adverse effects of

air bags, including higher deployment thresholds, dual level inflators,

smart air bags, and various other changes to air bags. In issuing its

proposal, the agency recognized that, for many vehicles, depowering has

a shorter leadtime than any of the other alternatives. The agency also

explained that a change in Standard No. 208 is not needed to permit

manufacturers to implement these other alternatives.7 The agency

explained further:

\7\ NHTSA explained that the existing provisions of Standard No.

208 already provide considerable design flexibility for

manufacturers. The Standard's automatic protection requirements are

performance requirements and do not specify the design of an air

bag. Instead, vehicles must meet specified injury criteria,

including criteria for the head and chest, measured on properly

positioned test dummies, during a barrier crash test, at speeds up

to 30 mph.

As the AAMA correctly noted in its comments on the NPRM, the

Standard requires air bags to provide protection for properly

positioned occupants (belted and unbelted) in a 30 mph crash, and

very fast air bags may be necessary to provide such protection.

However, the standard does not require the same speed of deployment

in slower speed crashes or in the presence of out-of-position

occupants. Vehicle manufacturers have the flexibility under the

Standard to use dual or multiple level inflator systems and

automatic cut-off devices for out-of-position occupants and rear-

facing infant restraints. Concepts such as dual level inflator

systems and devices that sense occupant position and measure

occupant size or weight are not new, and were cited by the agency in

its 1984 rulemaking requiring automatic protection. Also, Standard

No. 208 does not specify a minimum vehicle speed at which air bags

must deploy. Thresholds could be raised substantially for most

current vehicles without creating a Standard No. 208 compliance

problem. In addition, installation of smart air bags and replacement

of mechanical air bag sensors with electronic ones are permitted.

Therefore, regulatory changes are not needed to permit manufacturers

to implement these solutions.

---------------------------------------------------------------------------

[[Page 12964]]

The agency expects to ultimately require smart air bags through

rulemaking. In the meantime, the agency is not endorsing depowering

over other solutions. Instead, the agency is proposing a regulatory

change to add depowering to the alternatives available to the

vehicle manufacturers to address this problem on a short-term basis.

To the extent that manufacturers can implement superior alternatives

for some vehicles, the agency would encourage them to do so.

NHTSA shares the concern of the Parent's Coalition that depowering

will not likely save all children and will likely result in trade-offs

for adults. That is why the agency is limiting the duration of its

depowering amendments and plans to conduct rulemaking to require smart

air bags. In the meantime, however, NHTSA wants to be sure that the

vehicle manufacturers have the necessary tools to address immediately

the problem of adverse effects of air bags. Standard No. 208's existing

performance requirements do restrict the use of depowering, since

substantially depowering the air bags of many vehicles would make those

vehicles incapable of complying with the standard's injury criteria in

a 30 mph barrier crash test. Accordingly, to permit use of this

alternative, it is necessary to amend Standard No. 208.

The issuance of any rule narrowing the discretion that vehicle

manufacturers have had since the 1984 decision, whether by requiring

depowering, higher thresholds, other changes to air bags, or smart air

bags, would involve considerably more complex issues than a rulemaking

simply adding greater flexibility. The agency would need to assess

safety effects, practicability, and leadtime for the entire vehicle

fleet. NHTSA will assess those types of issues in its rulemaking for

smart air bags. The agency notes that there may not be any reason to

have higher deployment thresholds with some types of smart air bags,

since a low-power inflation may be automatically selected for low

severity crashes.

Until the agency conducts its rulemaking regarding smart air bags,

it believes it is best to focus on ensuring that manufacturers have

appropriate flexibility to address the problem of adverse effects of

air bags. This will enable the manufacturers to select the solutions

which can be accomplished most quickly for their individual models.

NHTSA encourages the vehicle manufacturers to use the best available

alternative solutions that can be quickly implemented for their

vehicles, whether depowering, higher thresholds, other changes to air

bags, smart air bags, or a combination of the above. The agency notes

again that the vehicle manufacturers need not wait for further

rulemaking to begin installing smart air bags, and encourages them to

move in that direction expeditiously.

NHTSA notes that, as discussed in the January 1997 NPRM, CFAS and

Public Citizen petitioned the agency in November 1996 to commence a

rulemaking proceeding to consider requiring dual inflation air bags and

to specify deployment thresholds. The agency stated in that notice that

it considered the petitions to have been granted to the extent that the

NPRM analyzed and discussed issues raised by the petitioners and

subjected that material to public comment. NHTSA will continue to

consider the issues raised by those petitioners in its planned

rulemaking on smart air bags.

Consumers Union urged the agency to evaluate whether the incidence

of fatalities caused by air bags in low speed collisions may be

disproportionately high in certain specific makes and models of

passenger vehicles. That organization stated that it would be a great

disservice to the public to reduce the protection of air bags in all

cars because certain specific models are improperly designed. NHTSA

notes that while the level of risks from air bags undoubtedly varies

between different makes and models, a review of air bag fatalities

indicates that the problem is a general one, not limited to a few

makes/models.

A few commenters argued against the agency's depowering proposal on

the grounds that the proposed amendments would result in a greater

number of lives being lost than saved, both for passengers and drivers.

While the agency recognizes the possibility that there is a

potential for net disbenefits from depowering, it believes it must

consider both the short-run and long-run implications of this

rulemaking on safety. Ultimately, the continued availability of any

safety device as standard equipment, whether provided voluntarily by

manufacturers or pursuant to a regulation, is dependent on consumer

acceptability. The agency believes that air bags which fatally injure

occupants, particularly children in low speed crashes, place the

concept of air bags at risk, despite their overall net safety benefits.

Accordingly, to help ensure that air bags remain acceptable to

consumers and ultimately achieve their full potential in the future,

the agency believes it is reasonable to accept some short-term safety

tradeoffs associated with depowering, while better solutions are being

developed.

NHTSA also notes that, as discussed in the NPRM, it believes that

even if the net effect were negative, the opportunity to avoid the

deaths of a significant number of children who would otherwise be

fatally injured by air bags justifies foregoing the opportunity to save

some unbelted teenage and adult passengers. There are several reasons

for this policy choice.

First, it is not acceptable that a safety device cause a

significant number of fatalities in circumstances in which fatal or

serious injuries would not otherwise occur. In making this statement,

the agency draws a distinction between air bags which are fatally

injuring young children in low speed crashes in which the other vehicle

occupants are uninjured, and other safety devices which may on occasion

unavoidably substitute one type of injury for another type that would

occur in their absence (safety belts are a good example).8 Those

fatalities are particularly unacceptable in light of the agency's

analysis showing that depowering air bags can significantly reduce the

number of children being fatally injured by air bags.

---------------------------------------------------------------------------

\8\ In severe collisions, safety belts can seriously bruise the

chest of an occupant or even cause rib fractures. However, the

restraining force of the belt would also likely prevent even more

serious chest or head injury from the occupant's striking the

interior components of the vehicle.

---------------------------------------------------------------------------

Second, it is also particularly unacceptable that the vehicle

occupants being fatally injured are young children, and that the number

of those deaths is steadily growing. In confronting the possibility of

inevitable short-term safety tradeoffs between young children and

unbelted occupants over 12 years of age, the agency believes that

greater weight must be placed on protecting

[[Page 12965]]

young children. NHTSA has always given a high priority to protecting

children and accordingly has applied these different cost-benefit

considerations to its rulemaking affecting children. The agency's

activities related to school bus safety standards are an example of

this policy.

A major reason for giving priority to protecting young children is

that they are less mature than teenagers and adults and thus less able

to exercise independent judgment, assess the risks and take action to

improve their safety. Young children are more dependent on the judgment

and actions of other persons. The oldest of the 38 children who have

been fatally injured by an air bag was nine years old, and most of the

children have been much younger. The agency is concerned about the

safety of the unbelted teenagers and adults who might be affected by

depowering, but is increasing its efforts to persuade them to protect

themselves by buckling their safety belts as required by the laws of 49

States and the District of Columbia. NHTSA is also increasing its

efforts to persuade parents to ensure that all children are properly

restrained.

B. 80 g's Chest Injury Criterion vs. Sled Test

As discussed above, Standard No. 208 currently specifies that

occupant protection is measured in a full scale crash test in which a

vehicle equipped with test dummies at the outside front seating

positions is crashed into a barrier. Specific injury criteria measured

on the test dummies, including those evaluating chest acceleration and

head injuries, must be met in barrier crashes at speeds up to 30 mph,

and at a range of angles up to 30 degrees off-center.

In August 1996, AAMA submitted a petition requesting that the

unbelted crash test requirement be replaced with a generic sled test

protocol. Under that protocol, all of a vehicle, or a portion of the

vehicle representing the interior, would be mounted on a sled. The sled

would be decelerated from 30 mph over a time period of 143 milliseconds

according to a specific deceleration-time curve which approximates a

vehicle's crash pulse. There would not be an angle test, only a direct

frontal test. AAMA requested that the same crash pulse be used for all

vehicles. That organization asserted that its recommended test protocol

would allow for lower powered inflators to be introduced into the

market as quickly as possible, while maintaining air bag protection for

all occupants.

After NHTSA conducted a vehicle test and discovered that AAMA's

initially recommended crash pulse could allow a vehicle to meet

Standard No. 208's existing injury criteria without an air bag, in

November 1996 that organization suggested using a more severe crash

pulse: 125 msec., which corresponds to 17.2 g's.9 AAMA also

recommended at that time that the agency include neck injury criteria

to evaluate air bag performance as it relates to the recommended crash

pulse, in addition to the current injury criteria which, among other

things, limit chest acceleration to 60 g's. The neck injury criteria

are likely to be the limiting factor in determining the maximum

allowable depowering level for a particular vehicle.

---------------------------------------------------------------------------

\9\ See pages III-45 and 46 of the PRE which show that the 143

millisecond pulse was significantly longer in duration and lower in

amplitude when compared to the 125 msec pulse.

---------------------------------------------------------------------------

After reviewing the available information, NHTSA proposed two

alternative temporary amendments to Standard No. 208: (1) Increase the

current chest acceleration limit from 60 g's to 80 g's, or (2) replace

the unbelted crash test requirement with a sled test protocol

incorporating the 125 millisecond crash pulse. The agency noted that if

both of these changes were adopted, a manufacturer could select either

alternative at its option, but could not mix the two options.

AAMA, AIAM, Advocates, Autoliv, Public Citizen, and all vehicle

manufacturers addressing the issue, stated that only the sled test

alternative should be adopted. AAMA stated that using the sled test

will allow further optimization of air bag performance and will save

many additional lives each year as well as substantially reduce the

risk of air bag-related injuries. That organization stated that the

sled test allows depowering for all vehicles in the quickest possible

manner.

NHTSA notes that AAMA estimated that only 31 percent of the fleet

could be depowered under the 80 g's alternative. That organization did

not provide specific data or analysis to support that figure. However,

Ford commented that neither it nor the agency has conducted angular

barrier modeling or tests that could be the basis for judging

performance of depowered air bags in angular barrier tests. Ford stated

that computer modeling by it and the agency, as well as sled tests,

indicate that HICs and femur loads increase with depowered air bags,

and Ford would have no basis for judging that vehicles equipped with

substantially depowered air bags would meet compliance criteria in

angular tests.

AIAM stated that the sled test would result in the fastest way to

achieve depowering. Nissan stated that the sled test provides the

fastest and most efficient approach to allow for depowering. Autoliv

stated that the sled test was consistent with international

harmonization. Several safety groups, including Advocates and IIHS,

favored the sled test, because they believed that it provides the

quickest way to reduce risk.

In contrast, other safety groups (CFAS, Consumers Union, and the

Parents Coalition) and some component manufacturers (AirBelt Systems,

AVS Technologies, and Precision Fabrics Group (PFG)) criticized the

sled test. CFAS stated that sled testing fails to account for many

aspects of interior vehicle safety that contribute to occupant

injuries. Consumers Union stated that the sled test is a ``wholly

inadequate substitute for whole-car crash tests in determining specific

vehicle performance.'' PFG was concerned that the generic pulse does

not consider such things as automobile crush and steering wheel

response.

IIHS was the only commenter to support use of either approach.

After reviewing the comments, NHTSA has decided to adopt the sled

test as an alternative to the current unbelted barrier test for a

limited time. The agency believes that this approach provides

manufacturers with the maximum flexibility to provide the fastest

depowering on the widest portion of the vehicle fleet. As the agency

stated in the NPRM, the sled test reduces the time and cost of doing

certification testing, since many more sled tests can be conducted in

the same time period than can crash tests. The agency also believes

that the standardized crash pulse and air bag initiation time for all

vehicles will allow commonality in air bag systems, requiring less

development time and thus eliminating the need for greater variations

of air bag system components to accommodate differences in actual car

crash pulses. Such rapid implementation is necessary to address the

potential risk posed to vehicle occupants in low speed crashes. The

agency has decided not to provide an option of complying with the 80

g's alternative, since no manufacturer indicated it planned to pursue

that approach.

As discussed in the NPRM, NHTSA continues to believe that a full

scale vehicle crash is a better means of measuring crashworthiness than

a sled test, since it evaluates many more factors about a motor

vehicle's crashworthiness than a generic sled test. The NPRM stated

that

[[Page 12966]]

The primary disadvantage of the generic sled test is that the test

measures only air bag performance and not total vehicle performance.

The approach also eliminates the effect of angle test requirements

which ensure protection in frontal impacts that occur at a range of

angles rather than purely head-on.

There are other disadvantages with the sled test, including that a

sled test does not simulate the triaxial acceleration characteristics

of an actual vehicle crash. In other words, a sled test involves

acceleration from only a single preset direction, while pulses for

actual vehicle crashes can have significant vertical and lateral

components of acceleration that can affect occupant kinematics and

restraint performance. Nor does a sled test evaluate dynamic intrusion

into and deformation of the passenger compartment; structural crush;

the steering column's energy absorbing characteristics and load bearing

capability; and movement of the passenger compartment due to localized

buckling.

Nevertheless, NHTSA has decided to allow the sled test as a

temporary 10 measure given the need to provide manufacturers with

maximum flexibility to respond rapidly to the risk posed by air bag

activation in low speed crashes.

---------------------------------------------------------------------------

10 The issue of whether to make this amendment temporary

or permanent is discussed in detail below.

---------------------------------------------------------------------------

NHTSA notes that, as discussed in the NPRM, it conducted a series

of tests using the revised AAMA crash pulse. One vehicle passed all of

Standard No. 208's current injury criteria without an air bag, but had

a very small margin of compliance for passenger chest g's. Another

vehicle met the standard's current injury criteria without an air bag

for the passenger side, but slightly exceeded the driver chest g's

limit. The agency's testing also showed that air bag deployment is

necessary for a vehicle to comply with the new neck injury criteria,

discussed later in this notice. Given that manufacturers must design

their vehicles with sufficient margin of compliance to ensure that all

vehicles will pass a standard's requirements, and given the addition of

the new neck injury criteria, the agency believes that the sled test

adopted in this rule will ensure an appropriate level of depowering

without diminishing the benefits of unbelted testing. While the agency

recognizes that the sled test is not an ideal means for ensuring that

chest and head protection are provided in specific vehicles, and that

the 30 mph generic pulse represents a barrier crash test at a speed

lower than 30 mph, NHTSA believes it is an appropriate interim approach

to help facilitate depowering.

C. Application of the Amendment to Driver Air Bags

In the NPRM, the agency noted a number of differences between the

passenger and driver air bag problems. The agency explained that while

the annual number of child fatalities is small but growing steadily,

the annual number of driver fatalities does not appear to be growing.

At the time of the NPRM, while the agency was aware of 18 children who

had been fatally injured by air bags during 1996, it was aware of only

one driver who had been fatally injured by an air bag in the United

States during that year. (As of now, the agency is aware of 22

children, and three drivers, who were killed by air bags during 1996.)

NHTSA noted in the NPRM that most child fatalities had occurred in

model year 1994 and 1995 vehicles. In contrast, only 4 of the driver

fatalities had occurred in a vehicle manufactured after model year

1992. The absence of fatalities in recent model year vehicles appeared

even more pronounced in the case of female drivers 5 feet 2 inches or

shorter. Only one female driver 5 feet 2 inches or shorter had died in

a post model year 1992 vehicle. Most fatalities of short-statured

female drivers had occurred in model year 1990-1992 vehicles. (The

figures and fatality patterns in this paragraph remain unchanged, as of

the date of issuance of this final rule, except that the number of

driver fatalities in post model year 1992 vehicles is now 5.)

The agency noted in the NPRM that because driver air bags have been

produced in large numbers for several years longer than passenger air

bags, the vehicle manufacturers have had time in a number of instances

to redesign driver air bags to incorporate a number of countermeasures

to reduce the risk to out-of-position occupants. NHTSA requested

information on the potential that current driver air bags have for

creating adverse effects, including relevant design changes that have

already been made to driver air bags.

NHTSA requested information on the number of driver air bag

fatalities that have occurred to date, and on whether there is a need

to change Standard No. 208 to permit varying levels of depowering. The

agency noted that, based on limited testing and modeling, 20 to 35

percent depowering of driver air bags appeared to result in only slight

increases in the injury levels ``experienced'' by a test dummy. NHTSA

stated that it believes that the presence of energy absorbing steering

columns explain why the driver air bag can depowered without

significantly affecting chest g's.

The vehicle manufacturers urged the agency to amend Standard No.

208 to allow depowering for the driver side as well as the passenger

side. AAMA stated that its design goal for depowering is to reduce to

as close to zero the possibility of a fifth percentile female being

injured by the air bag. That organization stated that not allowing

depowering for the driver position would continue to place these

occupants at unnecessary risk.

IIHS stated that although most public attention has focused on the

problem of air bag injuries to children, it is clear that drivers also

are being injured by inflating air bags. That organization stated that

much of its analysis has focused on the potential benefits to drivers

of depowering air bags. IIHS therefore argued that the alternative

compliance procedures proposed by NHTSA should apply to both driver and

passenger protection.

NTSB stated that given the awareness that air bags at the current

energy level can be highly injurious to both drivers and passengers, it

recommends that depowering be extended to both passenger and driver

positions.

AVS Technologies, by contrast, stated that the amendment should

apply only to the passenger side. According to that company, the

disbenefits of increased fatalities in comparison to the relatively

small number of serious deployment injuries does not justify amending

the regulation to accommodate depowered driver air bags. AVS

Technologies also argued that the problem of small statured drivers can

be mitigated by implementation of available technologies such as

adjustable steering columns that allow the small statured adult to

position the steering wheel further away from the head and chest.

In response to the NPRM, NHTSA received relatively little

information on whether there was a need to change Standard No. 208 to

permit depowering. Ford, however, stated that as air bag technology and

dummy testing technology has advanced, air bags have been gradually

depowered. That company stated that with today's technology, some early

air bags could be redesigned to meet Standard No. 208's injury criteria

with lower inflation speeds. Ford noted that tests by the agency have

demonstrated that limited depowering is being incorporated into newer

vehicle designs. Ford added, however, that most current air bag designs

(some of which are not yet in production) have already been depowered

to some degree and cannot

[[Page 12967]]

be further depowered without unduly increasing the risk of failing to

meet some of the dummy injury criteria in the present Standard No. 208

barrier crash test with unbelted dummies.

After considering the comments, NHTSA has decided to amend Standard

No. 208 to allow depowering for the driver side as well as the

passenger side. While relevant supporting data are considerably more

limited for the driver side than the passenger side, the agency wishes

to ensure that manufacturers have the flexibility to quickly address

driver side risks to small females and the elderly. NHTSA notes,

however, that fatalities involving small females and the elderly are

rare. Depowering driver air bags will also help reduce arm injuries.

D. Duration of Amendment

As indicated above, in developing the January 1997 proposal, NHTSA

considered an array of approaches that would address the air bag safety

problem. Among other things, the agency considered higher deployment

thresholds, dual stage inflators, smart air bags, and various other

air-bag related changes.

After reviewing these alternatives, NHTSA tentatively concluded

that there are various alternatives already allowed by Standard No. 208

that may be superior to depowering, i.e., alternatives that result in

equal or greater benefits without raising the possibility of adverse

safety tradeoffs, but whose leadtime is longer than that of depowering.

The agency therefore tentatively concluded that while depowering

appears to be an appropriate interim solution, there is no need for

permanently changing the Standard to enable manufacturers to fully

address the adverse side effects of air bags.

NHTSA noted that some commenters on earlier notices, including

Takata, had expressed concern that a reduction in Standard No. 208's

performance requirements may delay the introduction of superior

alternatives. The agency stated that it did not believe a short-term

temporary amendment would result in such a delay, but would instead

provide maximum flexibility to the vehicle manufacturers to quickly

address the problem, while they work on better solutions. The agency

also explained that its forthcoming proposal for smart air bags would

seek to ensure that air bags reach their full fatality and injury

reducing potential.

NHTSA recognized, however, that the proposal to permit or

facilitate depowering of air bags was on a faster track than the

rulemaking to require smart air bags. The agency noted that if it

permitted depowering until smart bags are introduced, the question

would arise of how the agency should limit the duration of the

temporary amendment for depowering. The agency noted that one approach

would be to specify a several year duration and revisit the issue in

the context of the rulemaking on smart air bags.

The agency received numerous comments concerning the appropriate

duration for the depowering amendment. The vehicle manufacturers, IIHS,

and CVC argued against including a ``sunset'' clause; a number of

safety groups and suppliers argued that a sunset for the amendment is

critical, and specifically conditioned their support for depowering

upon a sunset provision.

AAMA stated that there is no reason at this time to limit the

duration of depowering. That organization stated that reducing the

energy output of air bag inflators should be viewed as an important

step toward development of advanced technology air bags. According to

AAMA, there is no reason to assume that the current energy level of air

bags provides optimum occupant protection, especially for belted

occupants, and it would be a mistake to assume that it must be

reinstated after some interim period. AAMA argued that its analyses

show that depowering alone can save many additional lives per year

compared to today's air bag energy levels.

AAMA also argued that even if it did make sense to couple

depowering to more advanced technology, that technology is currently

unknown. That organization stated that it should be apparent that

defining what a ``smart air bag'' is, is not a simple, straightforward

endeavor. According to AAMA, it is premature and highly inappropriate

to consider a sunset date for depowering technologies that are known to

be at least partial solutions to the concerns regarding inflation

related injuries.

AAMA also argued that as manufacturers consider application of

depowered air bag systems, a sunset provision would become a

significant factor in assessing the practicability of design changes.

That organization argued that this will especially be the case for

models with product lives scheduled to end in the period shortly after

the sunset date. According to AAMA, the benefits expected from changes

to depowering for a short period of time, followed by further changes

to meet advanced technology air bag requirements, may not justify the

design/development/certification costs.

AIAM stated that whatever change is made to Standard No. 208, the

basic concept of the revised regulation needs to be permanent. That

organization argued that investments to optimize safety belt/air bag

system designs can only be made if manufacturers know that the barrier

crash test using unbelted dummies will not be reimposed in a short

time. AIAM also argued that the action in this rulemaking should not be

linked to the ``smart'' air bag system rulemaking that NHTSA

contemplates.

IIHS stated that because of uncertainty about the availability and

efficacy of future technology, and because it does not agree that the

proposed regulatory changes will lead to the tradeoffs NHTSA

anticipates--it does not support the inclusion of a sunset provision

for the proposed rule changes. IIHS stated that limiting the duration

of the depowering amendment would be superfluous and counterproductive,

considering the agency anticipates further rulemaking on smart air

bags.

CVC stated that it is concerned by the time frame allowed for

depowered air bags under NHTSA's proposal. That organization stated

that even if NHTSA promptly adopts the sled test, automakers would

still probably not be able to complete the changeover of their fleets

until sometime in model year 1999--and then could be faced with the

prospect of changing their entire fleets back to full-scale crash-

testing soon thereafter. CVC stated that it agrees that smart air-bag

technology holds promise for the future, but there is little reason to

assume that this technology will be sufficiently developed and tested

to permit mass installation just three years from now. CVC argued that

forcing the rapid implementation of new untested technology could

produce a whole new wave of safety concerns (inadvertent, failed or

improper deployment), leading to new occupant injuries and additional

adverse publicity for air bags.

Morton stated that it firmly believes that the depowering amendment

should be temporary. That company stated that the question of duration

cannot be easily answered at this point. It stated its belief that the

suggested approach in the NPRM to specify a several year duration and

to revisit the issue in the context of the rulemaking on smart air bags

is the appropriate option at this point.

General Dynamics stated that it supports the current NHTSA proposed

solutions, but that support is based on NHTSA's statement that

implementation of proposed solutions will be recognized as temporary

measures until ``smart'' solutions

[[Page 12968]]

become available. General Dynamics stated that it disagrees that the

proposed temporary measures will be required for the next several model

years as smart systems are phased in. That company stated that it

believes that the disbenefits of the NHTSA temporary measures will grow

in those years and argues that a near-term mandate for smart air bags

is required.

AirBelt Systems stated that ``either one of the proposed

approaches, due to the adverse safety tradeoffs which it argues will

take place, must be viewed only as an extremely temporary step at

possibly helping to solve the current dilemma of severe injury and

deaths to children from air bags.''

TRW stated that it is concerned that the proposed interim action

could potentially stifle the urgent need for more elegant and

comprehensive solutions that potentially accommodate a much better

balance in protecting children, belted and unbelted occupants, varying

size occupants and varying positioned occupants. TRW stated that,

accordingly, the depowering amendment should be allowed during the

period where an aggressive phase-in schedule exists to develop and

introduce varying degrees of advanced restraint system technologies.

AVS Technologies stated that, if adopted, the sled alternative

should remain in effect for a limited period of time. According to that

company, it should be replaced within two years by a temporary modified

vehicle barrier test.

CFAS stated that if NHTSA accepts manufacturer arguments that

depowered inflators are effective in solving current problems, the

agency must recognize that depowered inflators will involve a

substantial amount of manufacturer resources to design, develop, test

and install on a widespread basis. That organization stated that given

the investment in depowered inflators, manufacturers will be reluctant

to develop new and better technological solutions to improve their air

bag systems. CFAS expressed concern that, consequently, proposals to

alter Standard No. 208 will become permanent, not temporary, and will

work against implementation of smart air bags. CFAS stated that if

NHTSA adopts depowering, it suggests that the agency require

manufacturers to use a dual or multi-staged system, using a

``depowered'' inflator for low speed crashes and a higher-powered

inflator for higher speed crashes.

Public Citizen stated that implementation of a revised Standard No.

208 should supersede this depowering rulemaking as rapidly as possible,

and no later than model year 1999 vehicles. That organization stated

that there should be requirements for dual-or multi-stage inflation air

bags by model year 1999. It stated that, according to comments already

submitted to the agency by air bag suppliers, dual-stage inflation

systems could be installed in model year 1999 vehicles.

After considering the comments, NHTSA has determined that there is

no need to permanently reduce Standard No. 208's performance

requirements to enable manufacturers to fully address the adverse

effects of air bags. This is because there are various alternatives,

albeit with longer technological development and implementation

leadtimes than depowering, that are already allowed by the standard and

that appear likely to result in equal or greater benefits than

depowering without creating adverse safety tradeoffs. Thus, the agency

views depowering as an interim approach, while the vehicle

manufacturers develop and implement better solutions.

One technological alternative is a dual or multiple level inflator,

which has the effect of causing an air bag to perform as a

``depowered'' air bag in low to moderate speed crashes (and possibly in

all crashes in which occupants are belted or the seat is in a forward

position), and as a fully powered air bag to provide protection to

unbelted occupants in higher speed crashes. Thus, dual or multiple

level inflators appear to offer all of the benefits associated with

depowering without the tradeoffs, and may either enable an air bag to

qualify as a smart air bag or be one of the major building blocks of a

smart air bag. The agency observes that several suppliers have

commented that this and/or other technologies are available for

introduction as early as model year 1999. NHTSA believes it is

reasonable to expect the vehicle manufacturers to move rapidly to adopt

such technologies, rather than to continue with single-inflation-level,

depowered air bags.11 The agency also notes that adoption of dual

or multi-level inflators is not inherently dependent on the use of

advanced occupant position sensing devices.

---------------------------------------------------------------------------

\11\ NHTSA notes that concepts such as dual stage inflators are

not new and were considered by the agency in deciding to require

automatic protection. For example, in the early and mid-1970's,

various vehicle manufacturers reported favorable results in testing

the ability of various dual level or variable inflation systems for

air bags to address the problem of out-of-position children. In

1980, NHTSA informed the industry about its analysis of a number of

possible technological solutions, including dual-inflation air bags,

chambering air bags and top-mounted air bags. The July 11, 1984

Final Regulatory Impact Analysis (FRIA) for the 1984 final rule

requiring the installation of automatic occupant restraints in

passenger cars (49 Fed. Reg. 28962; July 17, 1984) listed a variety

of potential technological means for addressing the problem of

injuries associated with air bag deployments (FRIA, pp. III-8 to

10): a dual level inflation system whose operation is based on

impact speed; a dual level inflation system whose operation is based

on a switch in the vehicle seat or elsewhere that measures occupant

size or weight and senses whether an occupant is out of position; a

dual level inflation system whose operation is based on an

electronic proximity detector in the dashboard; and other

technological measures such as bag shape and size, instrument panel

contour, aspiration, and inflation technique.

---------------------------------------------------------------------------

Contrary to AAMA's suggestion, the agency is not assuming that the

current energy level of air bags provides optimum occupant protection,

especially for belted occupants. Instead, the agency recognizes that

more advanced air bag designs can provide appropriate inflation rates

for different levels of crash severity, occupant size/position, and

belted/unbelted conditions. The agency observes that one of the primary

criticisms of current air bags, that they inflate in the same one-size-

fits-all manner regardless of occupant size and position and crash

severity, will also be true for depowered air bags, albeit at a

different level. However, this limitation of current air bag designs,

and the contemplated depowered air bags, can be addressed by the use of

dual or multiple level inflators.

NHTSA also disagrees with IIHS's suggestion that it would be

superfluous to limit the duration of the depowering amendment, since

the agency anticipates further rulemaking on smart air bags and would

likely review all requirements of the standard. While the agency

expects that a variety of test conditions may be added as part of a

rulemaking to require smart air bags, and while the agency has recently

sought public comment on the issue, 62 FR 8917 (February 27, 1997),

based on current belt use rates, there is no reason to assume that the

basic concept of a simple 30 mph barrier test for the unbelted

condition would be dropped. As noted earlier in this notice, about half

of all occupants in potentially fatal crashes still do not wear their

safety belts.12 Moreover, barrier testing is the most prevalent

and accepted means of measuring real world protection.

---------------------------------------------------------------------------

\12\ Even if the use rates were significantly higher, and an

analysis showed that dropping the unbelted test would have net

safety benefits for motor vehicle occupants, the agency could not

drop the test on its own initiative. As the agency noted in its

February 27, 1997 notice, legislation would be necessary to

authorize the agency to take that step.

---------------------------------------------------------------------------

NHTSA recognizes that there is substantial uncertainty as to how

quickly smart air bags can be

[[Page 12969]]

incorporated into the entire fleet. Accordingly, the agency is adopting

the approach suggested in the NPRM of specifying a several-year

duration for the depowering amendment, and will revisit the issue, to

the extent appropriate, in the context of a future rulemaking on smart

air bags.

The agency is specifying a termination date of September 1, 2001,

which roughly corresponds to the beginning of model year 2002. Based on

information provided at NHTSA's February 11-12, 1997 public workshop on

smart air bags, this appears to be a realistic date as to when the

vehicle manufacturers can install some kind of smart air bags

throughout their fleets, or at least more advanced air bags that

provide the benefits associated with depowering without the tradeoffs.

This expiration date assumes that the vehicle manufacturers will use

the discretion they have to rapidly introduce the new air bag

technologies that they and the suppliers have been developing, and will

begin implementation of advanced air bag technologies in many of their

vehicles before that date. For example, several suppliers have stated

that dual or multiple stage inflators are available for introduction

beginning as early as model year 1999, i.e., September 1, 1998, and

that various other advanced air bag technologies will become available

by that time or soon thereafter. NHTSA also believes that allowing

depowering for more than four calendar years should provide

manufacturers a reasonable amount of time to optimize depowered systems

(i.e., tailor venting strategies, etc.), rather than simply depowering

current systems without change. Manufacturers should not, however, read

the September 1, 2001 date as any indication that the agency, in its

smart air bag rulemaking, will not consider a requirement for a phase-

in for smart air bags that begins before that time.

F. Benefits and Trade-Offs

AAMA and IIHS submitted critiques of the analyses of benefits and

trade-offs presented in the PRE, arguing that the agency substantially

overstated the potential disbenefits of depowering. Among other things,

these commenters argued that the agency incorrectly assumed that 30 mph

barrier crash tests represent all fatal highway crashes.

Considerable comment was received on the real world results of the

GM Holden depowered air bag in Australia. AAMA argued that the agency

should have placed greater weight on that information. Several other

commenters suggested that less weight be placed on it. AVS Technologies

stated that if the greater effectiveness of Holden air bags is

primarily attributable to their effectiveness in preventing less severe

injuries (AIS 2), then it is unreasonable to assume that optimizing

U.S. air bags for the belted case will result in the same increased

levels of effectiveness for reducing fatalities. That commenter also

stated that while the PRE states the Holden system is more effective

for serious (MAIS 3+) chest injuries than U.S. air bags, the data show

that the Holden system is considerably less effective than its U.S.

counterpart in reducing MAIS 3+ head injuries. AVS Technologies argued

that, in any event, the figure for Holden effectiveness with respect to

MAIS 3+ injuries is of doubtful validity, given the small number of

cases. Richard Strombotne argued that the number of cases used in the

Holden analysis is so small that the uncertainty in the analysis

renders the results useless. Several commenters noted that Holden air

bags deploy at a higher threshold, and stated that the higher threshold

may account for a large part of the greater effectiveness of Holden air

bags.

The FRE responds to the various comments on benefits and trade-

offs, and presents revised estimates. The estimates presented in the

PRE and FRE for the sled test alternative can be summarized as follows.

The PRE estimated that if current rates of child fatalities were

experienced in an all-air-bag fleet, 128 children would be killed over

the life of a single model year's fleet. The figure of 128 included 38

infants in rear-facing infant seats and 90 older children. Based on

three-and-one-half more months of data showing no new cases of infant

fatalities, but increasing numbers of older child fatalities, the FRE

revises the total number of child fatalities up from 128 to 140. The

new total includes a reduced number (33) of infant fatalities and

increased number (107) of older child fatalities.

NHTSA emphasizes, as it did in the NPRM, that this and the agency's

other rulemaking proceedings and related efforts are intended to ensure

that risks of adverse effects of air bags are reduced so that these

theoretically projected air bag fatalities do not materialize, while

the potential benefits of air bags are retained to the maximum extent

possible.

One area of uncertainty that significantly affects both potential

benefits and tradeoffs is how much the vehicle manufacturers will

depower air bags. AAMA commented that the average level of depowering

will be 20 to 35 percent.

Based on test results and modeling, the FRE estimates that, if 35

percent is the upper end manufacturers adopt for depowering, 47

children would be saved. Using the same assumptions, the FRE estimates

that 34 to 280 fewer teenage and adult passengers may be saved. The FRE

recognizes that, if some air bags are depowered by more than 35

percent, more children would be saved, although there would also be

higher disbenefits. The agency notes that the PRE provided higher

estimates for both potential benefits and disbenefits, primarily

because it assumed greater levels of depowering. 13

---------------------------------------------------------------------------

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 2 ms after initiation

of the acceleration. Not all manufacturers determine acceleration

initiation the same way. What time zero determinations are used and of

those which one do you recommend?''

AAMA stated that the activation time should be changed to 20

2 ms after the time at which sled acceleration crosses 0.5

g, claiming that this change would provide a more definite test

criterion. Subaru stated that in determining time zero, it uses the

time when the sled acceleration exceeded 1 g as its acceleration

initiation. It believes that this method represents a real crash pulse

considering the proposed air bag firing time of 25 2 ms.

Toyota stated that the agency should define the starting point of the

crash pulse in the sled test. Toyota believed that either t=0 at the

0.5 g level during crash onset or 5 ms before 1 g is reached would be

acceptable. Volvo stated that since not all manufacturers determine

acceleration the same way, the agency should provide a ``methodology to

determine trigger time for the air bag.''

Only Volkswagen commented that the agency should not specify the

activation time. That company stated that specifying the activation

time is design restrictive and could limit ability to depower certain

systems.

NHTSA believes that it is appropriate to specify the activation

time. Except for Volkswagen, all manufacturers submitting comments on

this issue supported such a provision. The agency believes that such a

provision adds precision and objectivity to the test procedure.

NHTSA has decided to adopt the activation time requested by AAMA in

its February 7, 1997 comment; i.e., 20 2 ms after the time

at which the sled acceleration crosses 0.5 g. The agency notes that

this activation time modifies the proposed time only slightly and will

ensure that the air bag activates slightly earlier in the test than the

proposed time. Although the agency does not have specific data to

correlate the difference in performance between a 20 ms activation and

a 25 ms activation, NHTSA believes that the 20 ms activation is more

representative of a typical rigid crash.

5. Test Attitude

In S13.1, NHTSA proposed that the whole or partial vehicle be

mounted on a dynamic test platform ``at the manufacturer's design

attitude, so that the longitudinal center line of the vehicle is

parallel to the direction of the test platform travel and so that

movement between the base of the vehicle and the test platform is

prevented.''

In the supplemental letter to the manufacturers, NHTSA asked how a

manufacturer's test attitude and the vehicle's longitudinal centerline

are measured and what tolerances should be applied to these

measurements.

AAMA stated that the pitch and yaw angles are not particularly

critical and that +/- .5 degrees is sufficient, consistent with SAE

J826 July 95. Ford stated that the test procedure should specify the

manufacturer's nominal vehicle attitude (pitch) for mounting of the

vehicle on the sled, to attain result reproducibility. It stated that

head injury criteria (HIC), neck extension (and possibly other proposed

neck loads) are sensitive to pitch angle of vehicle mounting, because

pitch angle affects the trajectory of the unbelted dummies. Ford

favored the proposal for the tests to be at the ``manufacturer's design

attitude.'' Ford opposed setting the vehicle's pitch on the sled to

match that of the particular vehicle that is purchased when loaded to

test weight. It believed that approach would reduce the test's

reproducibility. Subaru stated that it mounts the partial vehicle

parallel to the direction of the test platform travel for its testing.

It stated although it had no problems related to improper alignment,

clear regulatory tolerances would be helpful.

Based on previous test experience and on the available information,

NHTSA has decided to incorporate the same test conditions already set

forth in S8 14 into the sled test specified in S13. With respect

to the vehicle test attitude, the agency has decided to add a provision

in S13.3 that is patterned after S8.1.1(d). The agency believes that

this provision addresses the concerns of the commenters without

unnecessarily complicating the test conditions. The agency believes

that requiring the attitude of the vehicle on the sled to be at any

alignment between the attitude in the ``as delivered'' condition and

the attitude in the ``fully loaded condition'' will eliminate

difficulties that have been caused by differences between the

theoretical fiduciary marks on blue prints and the actual assembly of

the vehicle. The agency further notes that the loading represents a

real world range of attitudes that the restraint system should be able

to handle.

---------------------------------------------------------------------------

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:

BILLING CODE 4910-59-P

[[Page 12975]]

[GRAPHIC] [TIFF OMITTED] TR19MR97.009

Issued on: March 14, 1997.

Ricardo Martinez,

Administrator.

[FR Doc. 97-6954 Filed 3-14-97; 3:42 pm]

BILLING CODE 4910-59-C