Federal Motor Vehicle Safety Standards; Occupant Crash Protection

SUMMARY: The agency is proposing to upgrade the agency's occupant

protection standard to require advanced air bags. While current air

bags have been shown to be highly effective in reducing overall

fatalities, they sometimes cause fatalities to out-of-position

occupants, especially children. The agency's proposal would require

that improvements be made in the ability of air bags to cushion and

protect occupants of different sizes, belted and unbelted, and would

require air bags to be redesigned to minimize risks to infants,

children, and other occupants. The advanced air bags would be required

in some new passenger cars and light trucks beginning September 1,

2002, and in all new cars and light trucks beginning September 1, 2005.

The agency's proposal is consistent with provisions included in the

NHTSA Reauthorization Act of 1998 which mandate the issuance of a final

rule for advanced air bags.

An appendix to this document responds to several petitions

concerning requirements for air bag performance.

DATES: Comments must be received by December 17, 1998.

ADDRESSES: Comments should refer to the docket number and notice

number, and be submitted to: Docket Management, Room PL-401, 400

Seventh Street, S.W., Washington, D.C. 20590 (Docket hours are from

10:00 a.m. to 5:00 p.m.)

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''

under ``Popular Information.''

For non-legal issues. 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. 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. Overview of Proposed Requirements

II. Executive Summary

III. Statutory Requirements

IV. Safety Problem and the Agency's Remedial Actions

A. Introduction

B. Background

1. Air Bags: Safety Issues

a. Lives Saved and Lost

b. Causes of Air Bag Fatalities

2. Air Bag Requirements

C. Comprehensive Agency Plan to Address Air Bag Fatalities

1. Interim Rulemaking Solutions

a. Existing and Future Vehicles-in-Use

b. New Vehicles

2. Longer-Term Rulemaking Solution

3. Educational Efforts; Child Restraint and Seat Belt Use Laws

V. Technological Opportunities

VI. Proposal for Advanced Air Bags

A. Introduction

B. Existing and Proposed Test Requirements

1. Tests for Requirements to Preserve and Improve Occupant

Protection for Different Size Occupants, Belted and Unbelted

a. Safety of Medium to Large Teenagers and Adults

b. Safety of Small Teenagers and Small Adults

2. Tests for Requirements to Minimize the Risk to Infants,

Children and Other Occupants from Injuries and Deaths Caused by Air

Bags

a. Safety of Infants

b. Safety of 3-Year-Old Children

c. Safety of 6-Year-Old Children

d. Safety of Small Teenage and Adult Drivers

C. Injury Criteria

D. Dummy Recognition

E. Lead Time and Proposed Effective Date

F. Selection of Options

G. Availability of Retrofit Manual On-Off Switches

H. Warning Labels

I. Questions

VII. Costs and Benefits

VIII. Rulemaking Analyses and Notices

IX. Request for Comments

Proposed Regulatory Text

Appendix--Response to Petitions

A. Petitions Requesting that New Test Requirements be Added to

Standard No. 208

B. Petition Requesting Extension of the Provision Allowing On-

Off Switches for Vehicles without Rear Seats or with Small Rear

Seats

C. Petitions Requesting a Permanent Option of Using Unbelted

Sled Test instead of Unbelted Barrier Test

D. Petition Objecting to NHTSA's Final Rule on Depowering

I. Overview of Proposed Requirements

The agency is proposing to upgrade Standard No. 208, Occupant Crash

Protection, to require advanced air bags. The advanced air bags would

be required in some new passenger cars and light trucks beginning

September 1, 2002, and in all new cars and light trucks beginning

September 1, 2005.

The agency is proposing to add a new set of requirements to prevent

air bags from causing injuries and to expand the existing set of

requirements intended to ensure that air bags cushion and protect

occupants in frontal crashes. There would be several new performance

requirements to ensure that the advanced air bags do not pose

unreasonable risks to out-of-position occupants. The proposal gives

alternative options for complying with those requirements so that

vehicle manufacturers would be free to choose from a variety of

effective technological solutions and to develop new ones if they so

desire. With this flexibility, they could use technologies that

modulate or otherwise control air bag deployment so deploying air bags

do not cause serious injuries or that prevent air bag deployment if

children or out-of-position occupants are present. To ensure that the

new air bags are designed to avoid causing injury to a broad array of

occupants, the agency would test the air bags using test dummies

representing 12-month-old, 3-year-old, and 6-year-old children and 5th

percentile adult females.

The agency is also proposing to ensure that the new air bags are

designed to cushion and protect a broader array of belted and unbelted

occupants, including teenagers and small women. The standard's current

dynamic crash test requirements specify the use of 50th percentile

adult male dummies only. Under the proposal, the agency would also use

5th percentile adult female dummies in the future. The weight and size

of these dummies are representative of not only small women, but also

many teenagers.

In addition to the existing rigid barrier test, representing a

relatively ``stiff'' or ``hard'' pulse crash in perpendicular tests and

a more moderate pulse crash in angled tests, the agency is proposing to

add a deformable barrier crash test, representing a relatively ``soft''

pulse crash.1 In relatively ``soft'' pulse

[[Page 49959]]

crashes, some current air bags do not deploy until after the occupants

have moved so far forward that they are near the air bag cover when

deployment begins. Such ``late deployments'' lead to high risks of

injury. This proposed new crash test requirement is intended to ensure

that air bag systems are designed so that the air bag deploys earlier,

before normally seated occupants, including small-statured ones, move

too close to the air bag. The agency is proposing to use 5th percentile

adult female dummies in this test. If an air bag opens in time for

small-statured occupants, who generally sit relatively far forward, it

will open in time for taller occupants, who sit farther back.

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\1\ ``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 for a

given test is a major determinant of the stringency of the test, and

how representative the test is of how a particular vehicle will

perform in particular kinds of real world crashes. Generally

speaking, the occupant undergoes greater forces due to secondary

collisions with the vehicle interior and restraint systems if the

crash pulse g's are higher at the peak, or the duration of the crash

pulse is shorter, which would lead to higher overall average g

levels.

In a relatively ``hard'' pulse crash, a vehicle's occupant

compartment decelerates relatively abruptly, creating a high risk of

death or serious injury. In a relatively ``soft'' pulse crash, there

is a lower rate of deceleration and proportionately lower risk of

death or serious injury. The nature of the crash pulse for a vehicle

in a given frontal crash is affected by a number of factors,

including vehicle speed, the extent to which the vehicle structure

forward of the occupant compartment collapses in a controlled manner

so that some of the crash energy is absorbed, whether the struck

object is fixed in place, the extent to which the struck object

collapses and absorbs energy, and, in the case of non-fixed struck

objects, the relative mass of the vehicle and the struck object.

Large cars typically have relatively mild crash pulses, while small

cars and utility vehicles typically have more severe crash pulses.

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The agency is proposing to phase out the unbelted sled test option

as requirements for advanced air bags are phased in. Finally, NHTSA is

proposing new and/or upgraded injury criteria for all of the standard's

test requirements.

II. Executive Summary

Air bags have been shown to be highly effective in saving lives.

They reduce fatalities in frontal crashes by about 30 percent. As of

June 1, 1998, air bags had saved an estimated 3,148 drivers and

passengers since their introduction in 1986. However, as of that same

date, the agency had confirmed a total of 105 crashes in this country

in which an air bag deployment had resulted in fatal injuries.

These deaths did not occur at random; they typically involved

certain common factors. The persons who have been killed or seriously

injured by an air bag were extremely close to the air bag at the time

of deployment. The persons shown to be at greatest risk have been (1)

unrestrained young children, who can easily be propelled close to or

against the passenger air bag before the crash as a result of pre-crash

braking, (2) infants in rear facing child seats, who ride with their

heads extremely close to the passenger air bag, and (3) drivers

(especially unrestrained ones) who sit extremely close to the steering

wheel. These drivers are most likely to be small-statured women.

Since the problem of air bag deaths first emerged, NHTSA has taken

a number of steps to address the problem. In late November 1996, the

agency announced that it would be implementing a comprehensive plan of

rulemaking and other actions (e.g., consumer education and

encouragement of State seat belt use laws providing for primary

enforcement of their requirements) addressing the adverse effects of

air bags.

Recognizing that a relatively long period of lead time is required

to make some types of significant design changes to air bags, the

agency's comprehensive plan called for both interim and longer-term

solutions. The interim solutions included temporary adjustments in

Standard No. 208's performance requirements to ensure that the vehicle

manufacturers had maximum flexibility to address quickly the problem of

risks from air bags. One temporary change was to permit manufacturers

to certify their vehicles to an unbelted sled test option, in which a

vehicle is essentially stopped quickly, but not actually crashed,

instead of to the standard's full scale unbelted crash test, in which a

vehicle is actually crashed into a barrier. This made it much easier

for the manufacturers to make quick design changes to their air bags.

Another temporary change was to permit the vehicle manufacturers to

install manual on-off switches for passenger air bags in vehicles

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

a rear facing child restraint.

Another interim measure taken by NHTSA was 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. Also, to address the problems faced by persons

who are in groups at special risk from air bags, the agency issued a

final rule exempting motor vehicle dealers and repair businesses from

the statutory prohibition against making federally required safety

equipment inoperative so that they may install retrofit manual on-off

switches for air bags in vehicles owned or used by such persons and

whose requests for switches have been approved by the agency.

In today's notice, NHTSA is proposing a longer-term solution. The

proposed amendments contemplate implementation of advanced air bag

system technology that would minimize or eliminate risks to out-of-

position occupants and enhance the benefits provided by air bags to

occupants of different sizes, belted and unbelted. The proposed

amendments are consistent with the NHTSA Reauthorization Act of 1998,

which requires advanced air bags.

In developing this proposal, the agency recognized that, to

minimize or eliminate air bag risks, either (1) air bag deployment must

be suppressed in situations that are risky to occupants, or (2) the air

bag must be designed to deploy in such a manner that it does not

present a significant risk of serious injury to out-of-position

occupants.

The agency has used a number of methods to obtain up-to-date

information regarding the technology needed for accomplishing these

purposes. These methods included meetings with individual

manufacturers, a public meeting and written information requests to

vehicle and air bag manufacturers for specified types of information.

In numerous meetings with vehicle manufacturers and air bag

suppliers, the agency discussed the steps that they were taking to

address adverse effects of air bags. The agency found that these

companies were working on a wide variety of technologies, involving one

or both of the approaches (i.e., modulation of deployment or

suppression of deployment) discussed above, to minimize or eliminate

air bag risks. Vehicle manufacturers and suppliers are working on

systems that would prevent an air bag from deploying in situations

where it might have an adverse effect, using, for example, sensors that

determine the weight, size, and/or location of the occupant. The

vehicle manufacturers and suppliers are also working on systems that

would modulate the speed and force of the air bag, using multiple level

inflators. The activation of those different levels is keyed to sensors

that determine such factors as crash severity, seat-track position,

occupant weight and/or size, and whether an occupant is belted or not.

They are also working on a variety of approaches that make air bags

less aggressive to out-of-position occupants, e.g., by changing fold

patterns, deployment paths, and venting systems.

NHTSA conducted a public meeting in February 1997 to obtain

information about available technologies, and separately asked the

National Aeronautics and Space Administration's Jet Propulsion

Laboratory (JPL) for help in obtaining information. JPL surveyed the

automotive industry and conducted

[[Page 49960]]

an analysis of the readiness of advanced air bag technologies.

Also, in April 1998, the agency sent an information request

concerning advanced air bag technology to nine air bag suppliers. This

effort supplemented NHTSA's other efforts to obtain information in this

area and was intended to ensure that the agency had the most up-to-date

information possible for this rulemaking.

The agency considered the information obtained in these various

endeavors, as well as other available information, in developing this

proposal.

To minimize air bag risks, the proposed amendments specify

alternative options that would allow use of the differing kinds of

technological solutions being developed or considered by the

manufacturers to effectively address this problem. For example, the

agency is proposing options that would test the performance of air bags

designed to inflate in a manner so they do not cause injuries. These

options, which are based on an approach recommended by the American

Automobile Manufacturers Association (AAMA), specify static out-of-

position tests. The agency is proposing use of several child dummies

(representing an infant, a 3-year-old, and a 6-year-old) and the Hybrid

III 5th percentile adult female dummy in these tests. Injury criteria

would be specified for each of the new dummies. The agency is also

proposing options that would test the performance of systems designed

to suppress air bag deployment in the presence of children and/or out-

of-position occupants.

NHTSA believes the proposed amendments would permit the vehicle

manufacturers to use any technology or design which can effectively

address the problem of adverse effects of air bags to out-of-position

occupants, without detracting from the ability of the vehicle to meet

Standard No. 208's other occupant protection requirements. The design

changes that can be used to meet the proposed requirements range from

relatively simple changes in the way air bags deploy to advanced

systems incorporating sensors which vary air bag deployment depending

on the size, weight and dynamic position of an occupant and crash

severity.

In addition to proposing requirements to address air bag risks to

out-of-position occupants, NHTSA is proposing to add to the standard's

dynamic frontal crash test requirements to ensure that improved

protection is provided to teenagers and adults of different sizes,

belted and unbelted, especially ones of smaller stature. Under Standard

No. 208's longstanding dynamic crash requirements, vehicles must meet

specified injury criteria, including ones for the head and chest,

measured on 50th percentile adult male test dummies (both belted and

unbelted) during rigid barrier crashes at any speed up to and including

48 km/h (30 mph) and at any angle up to 30

degrees.2 Thus, manufacturers are required to assure

compliance with occupant protection requirements in full scale vehicle

crashes representing a wide range of severities and crash pulses that

could potentially cause fatal injuries.

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\2\ As discussed elsewhere in this notice, Standard No. 208

currently includes an option for manufacturers to certify their

vehicles to an unbelted sled test as an alternative to the unbelted

barrier test requirement.

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However, despite their compliance with requirements specifying the

use of 50th percentile adult male dummies, some current air bags may

not provide appropriate protection to small adult occupants. Most

significantly, some designs do not take account of the special needs of

occupants who must sit relatively close to the air bag, such as small-

statured women drivers. In order to provide protection to someone who

sits close to the air bag, an air bag must deploy early in a crash

event. However, the air bags of some vehicles deploy late in certain

kinds of crashes (such as ones with soft pulses), after a small-

statured driver, even though belted, has struck the steering wheel. In

such a situation, the air bag cannot provide protection and may cause

harm. This same problem is faced by persons who sit close to the

passenger-side air bag.

To address this problem, NHTSA is proposing to add new dynamic

crash test requirements using 5th percentile adult female dummies.

Protection would be required to be demonstrated in a new ``offset

deformable barrier crash test,'' a test which replicates a kind of real

world crash likely to result in late deployment of many current air

bags. This test measures the performance of the sensor system as well

as the air bag in a 25-mph crash with a ``soft'' pulse, and would use

restrained dummies only. In addition, 5th percentile adult female

dummies would be added to the standard's existing 30-mph dynamic crash

test requirements, using both restrained and unrestrained dummies.

The agency has developed injury criteria and seat positioning

procedures that it believes are appropriate for small females. Among

other things, the agency is including neck injury criteria, since

persons close to the air bag at deployment are at greater risk of neck

injury. NHTSA notes that it is also proposing to upgrade the current

injury criteria specified for 50th percentile adult male dummies, and

to add neck injury criteria, to make them consistent with what the

agency is proposing for 5th percentile adult female dummies.

NHTSA recognizes that adding additional sizes of dummies would

increase testing costs, but believes that their addition is needed to

ensure that air bag performance is appropriate for occupants of

different sizes. NHTSA notes that upgrading Standard No. 208 by adding

a greater array of dummy sizes would parallel the agency's recent

upgrading of Standard No. 213, Child Restraint Systems, through the

addition of a greater array of sizes and weights of child test

dummies.3 Just as that final rule improved the safety of

child restraint systems by providing for evaluation of performance in a

more thorough manner, the addition of different size test dummies to

Standard No. 208 would improve protection for all occupants by

requiring more thorough evaluation of a vehicle's occupant protection

system.

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\3\ 60 FR 35126, July 6, 1995.

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The agency notes that it may issue a separate document proposing to

add the Hybrid III 95th percentile adult male dummy to Standard No.

208. With the addition of that dummy, occupant protection would be

measured for adult occupant sizes ranging from small-statured females

to large-statured males. The agency is not proposing to add the Hybrid

III 95th percentile adult male dummy in this notice because development

of that dummy has not yet reached the stage where it is appropriate for

incorporation into a Federal motor vehicle safety standard.

NHTSA also notes that during calendar year 1999 it expects to

propose a higher speed frontal offset requirement than that specified

for the current barrier test. The agency is still conducting research

regarding such a requirement. In addition, as more advanced technology

is developed, the agency may develop proposals to require further

enhancements in occupant protection under Standard No. 208.

To provide vehicle manufacturers sufficient time to complete

development of advanced air bag designs meeting the new requirements

proposed in today's notice, and implement them into their cars and

light trucks, NHTSA is proposing a phase-in of the upgraded

requirements beginning September 1, 2002, with full implementation

required effective September 1, 2005. The agency is proposing to

provide credits for early compliance with the rule. To address

[[Page 49961]]

the special problems faced by limited line manufacturers in complying

with phase-ins, the agency is proposing to permit manufacturers which

produce two or fewer carlines 4 the option of omitting the

first year of the phase-in if they achieve full compliance effective

September 1, 2003.

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\4\ The term ``carline'' refers to a group of vehicles which has

a degree of commonality in construction (e.g., body, chassis). The

term is used in NHTSA's automobile parts content labeling program

and is defined at 49 CFR Sec. 583.4.

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NHTSA notes that Standard No. 208 contains several provisions,

noted above, that were added as temporary measures to address air bag

risks. One is the provision permitting manufacturers to provide manual

on-off switches for passenger air bags in vehicles without rear seats

or with rear seats too small to accommodate a rear facing infant seat.

It expires on September 1, 2000.

The other is the provision permitting certification based on the

unbelted sled test alternative to the unbelted barrier test

requirements. It was scheduled to expire on September 1, 2001. However,

notwithstanding the expiration date currently specified in the standard

for the unbelted sled test option, the NHTSA Reauthorization Act of

1998 provides that the sled test option ``shall remain in effect unless

and until changed by [the final rule for advanced air bags].'' The

Conference Report states that the current sled test certification

option remains in effect ``unless and until phased out according to the

schedule in the final rule.''

In this notice, the agency is proposing to amend Standard No. 208

so that both the sled test option and the manual on-off switch

provision are phased out as the new requirements for advanced air bags

are phased in. During the phase-in, the sled test option and manual

cutoff provision would not apply to any vehicles certified to the

upgraded requirements, but would be available for vehicles not so

certified under the same conditions as they are currently available.

Thus, as manufacturers develop advanced air bags, they would need to

ensure that vehicles equipped with these devices meet all of Standard

No. 208's longstanding performance requirements as well as the new ones

being proposed today.

The agency is similarly proposing to amend its regulation

permitting the installation of retrofit on-off switches to specify that

these devices cannot be installed in vehicles that have been certified

to the new requirements for advanced air bags.

NHTSA notes that, as discussed later in this notice, the auto

industry and other commenters have raised a number of objections to the

existing unbelted barrier test requirements.5 While the

agency is not proposing alternatives to those requirements in this

notice, it is requesting comments on whether it should develop

alternative unbelted crash test requirements.

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\5\ The most significant objection is the argument that air bags

designed to enable vehicles to meet the unbelted barrier test at 30

mph will be too powerful for occupants, especially children, who are

extremely close to the air bag at time of deployment. The agency

notes, however, that this objection has been made primarily in the

context of the continued use of current, single inflation level air

bags, instead of the advanced ones that are the subject of this

proposal. Another significant objection concerns how representative

the barrier test is of real world crashes. As discussed later in

this notice, NHTSA is placing in the docket a technical paper which

analyzes the representativeness of those requirements with respect

to real-world crashes which have a potential to cause serious injury

or fatality.

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This notice also provides the agency's response to all outstanding

petitions concerning air bag performance.

III. Statutory Requirements

As part of the NHTSA Reauthorization Act of 1998,6

Congress required the agency to conduct rulemaking to improve air bags.

The Act directed NHTSA to issue, not later than September 1, 1998, ``a

notice of proposed rulemaking to improve occupant protection for

occupants of different sizes, belted and unbelted, under Federal Motor

Vehicle Safety Standard No. 208, while minimizing the risk to infants,

children, and other occupants from injuries and deaths caused by air

bags, by means that include advanced air bags.''

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\6\ The NHTSA Reauthorization Act of 1998 is part of P.L. 105-

178.

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The Act directs the agency to issue the final rule not later than

September 1, 1999. However, if it determines that the final rule cannot

be completed by that date, the final rule must be issued no later than

March 1, 2000. The final rule must be consistent both with the

provisions of the NHTSA Reauthorization Act of 1998 and with 49 U.S.C.

Sec. 30111, which specifies the requirements for Federal motor vehicle

safety standards.

The final rule must become effective in phases as rapidly as

practicable, beginning not earlier than September 1, 2002, and no

sooner than 30 months after the issuance of the final rule, but not

later than September 1, 2003. The final rule must become fully

effective by September 1, 2005. However, if the phase-in of the final

rule does not begin until September 1, 2003, NHTSA is authorized to

delay making the final rule fully effective until September 1, 2006.

To encourage early compliance, NHTSA is directed to include in the

NPRM means by which manufacturers may earn credits toward future

compliance. Credits, on a one-vehicle for one-vehicle basis, may be

earned for vehicles which are certified as being in full compliance

with the final rule and which are so certified before the beginning of

the phase-in period. They may also be earned during the phase-in if a

manufacturer's production of complying vehicles for a model year

exceeds the percentage of vehicles required to comply in that year.

In a paragraph titled ``Coordination of Effective Dates,'' the Act

provides that the unbelted sled test option ``shall remain in effect

unless and until changed by [the final rule for advanced air bags].''

The Conference Report states that the current sled test certification

option remains in effect ``unless and until phased out according to the

schedule in the final rule.''

IV. Safety Problem and the Agency's Remedial Actions

A. Introduction

While air bags are providing significant overall safety benefits,

NHTSA is concerned that current air bags have adverse effects on

certain groups of people in limited situations. Of particular concern,

NHTSA has confirmed 105 primarily low speed crashes in which the

deployment of an air bag resulted in fatal injuries to an occupant, as

of June 1, 1998. NHTSA believes that none of these occupants would have

died if the air bag had not deployed.7

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\7\ The vast majority of the deaths appear to have occurred in

crashes in which the vehicle had a change in velocity of less than

15 mph. Almost all occurred in crashes with a change of velocity

less than 20 mph.

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The primary factor linking these deaths is the proximity of

occupants to the air bag when it deployed. These deaths occurred under

circumstances in which the occupant's upper body was very near the air

bag when it deployed.

There were two other factors common to many of the deaths. First,

apart from 13 infants fatally injured while riding in rear-facing

infant seats, most of the fatally injured people were not using any

type of child seat or seat belt. This allowed the people to move

forward more readily than properly restrained occupants under

conditions of pre-impact braking or low level crashes. Second, the air

bags involved in those deaths were, like all current air bags, so-

called ``one-size-fits-all'' air bags that

[[Page 49962]]

have a single inflation level.8 These air bags deploy with

the same force in very low speed crashes as they do in higher speed

crashes.

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\8\ The Federal safety standards do not require a ``one-size-

fits-all'' approach to designing air bags. They permit a wide

variety of technologies that would enable air bags to deploy with

less force in lower speed crashes or when occupants are out of

position or suppress deployment altogether in appropriate

circumstances.

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The most direct behavioral solution to the problem of child

fatalities from air bags is for children to be properly belted in the

back seat whenever possible, while the most direct behavioral solution

for the adult fatalities is to use seat belts and move the driver seat

as far back as practicable. Implementing these solutions necessitates

increasing the percentage of children who are seated in the back and

properly restrained in child safety seats. It also necessitates

improving the current 69 percent rate of seat belt usage by a

combination of methods, including the enactment of State primary seat

belt use laws.9

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\9\ In States with ``secondary'' seat belt use laws, a motorist

may be ticketed for failure to wear a seat belt 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 seat belts.

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The most direct technical solution to the problem of fatalities

from air bags is to require that motor vehicle manufacturers install

advanced air bags that protect occupants from the adverse effects that

can occur from being too close to a deploying air bag.

All of these solutions are being pursued by the agency. However,

until advanced air bags are incorporated into the vehicle fleet,

behavioral changes based on better information and communication about

potential hazards and simple, non-automatic technology are the best

means of addressing fatalities from air bags, especially those

involving children.

To partially implement these solutions, and preserve the benefits

of air bags, while reducing the risk of injury to certain people, NHTSA

issued several final rules in the past year-and-a-half.

One rule requires new passenger cars and light trucks to bear new,

enhanced air bag warning labels. (61 FR 60206; November 27, 1996)

Another rule provided vehicle manufacturers with the temporary

option of certifying compliance based on a sled test using an unbelted

dummy, instead of conducting a vehicle-to-barrier crash test using an

unbelted dummy. (62 FR 12960; March 19, 1997) While vehicle

manufacturers could have depowered many or most of their vehicles' air

bags without changes to Standard No. 208, the final rule expedited this

process. In view of concerns that the gentler crash pulse of the sled

test would enable many vehicles to meet Standard No. 208's existing

injury criteria without an air bag deploying, the agency added neck

injury criteria to help ensure that air bags deploy and are not

depowered so much as to be ineffective. Unless the air bags deployed, a

vehicle would be very unlikely to be able to pass the neck injury

criteria limits. The agency concluded that depowering current single-

inflation level air bags would most likely reduce the adverse effects

of these air bags, although it also expressed concern that depowering

could result in less protection being provided to occupants in higher

speed crashes, especially for those who are unbelted and/or heavier

than average.

NHTSA has also issued two final rules related to manual on-off

switches. One extends the temporary time period during which vehicle

manufacturers are permitted to offer manual on-off switches for the

passenger air bag for vehicles without rear seats or with rear seats

that are too small to accommodate rear facing infant seats. (62 FR 798;

January 6, 1997) The other final rule exempts motor vehicle dealers and

repair businesses from the statutory prohibition against making

federally-required safety equipment inoperative so that they may

install retrofit manual on-off switches for driver and passenger air

bags in vehicles owned by or used by persons who are in groups at

special risk from air bags and whose requests for switches have been

authorized by the agency. (62 FR 62406; November 21, 1997)

On the behavioral side, the agency has initiated a national

campaign to increase usage of seat belts through the enactment of

primary seat belt use laws, more public education, and more effective

enforcement of existing belt use and child safety seat use laws.

In conjunction with the National Aeronautical and Space

Administration, as well as Transport Canada, and in cooperation with

domestic and foreign vehicle manufacturers, restraint system suppliers

and others through the Motor Vehicle Safety Research Advisory Committee

(MVSRAC), NHTSA has undertaken data analysis and research to address

remaining questions concerning the development and introduction of

advanced air bags.

In today's notice, the agency is proposing to require advanced air

bags.

B. Background

1. Air Bags: Safety Issues

a. Lives saved and lost. Air bags have proven to be highly

effective in reducing fatalities from frontal crashes, the most

prevalent fatality and injury-causing type of crash. Frontal crashes

cause 64 percent of all driver and right-front passenger fatalities.

NHTSA estimates that, between 1986 and June 1, 1998, air bags have

saved about 3,148 drivers and passengers (2,725 drivers (87 percent)

and 423 passengers (13 percent)).10 Of the 3,148, 2,267 (72

percent) were unbelted and 881 (28 percent) were belted. These agency

estimates are based on comparisons of the frequency of front seat

occupant deaths in vehicles without air bags and in vehicles with air

bags. Approximately half of those lives were saved in the last two

years. These savings occurred primarily in moderate and high speed

crashes.

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\10\ Studies published in the November 5, 1997 issue of the

Journal of the American Medical Association by the Insurance

Institute for Highway Safety (IIHS) and by the Center for Risk

Analysis at the Harvard School of Public Health confirm the overall

value of passenger air bags, while urging action be taken quickly to

address the loss of children's lives due to those air bags. IIHS

found that passenger air bags were associated with a substantial

reduction in crash deaths. The Center evaluated the cost-

effectiveness of passenger air bags and concluded that they produce

savings at costs comparable to many well-accepted medical and public

health practices.

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

Pursuant to the mandate in the Intermodal Surface Transportation

Efficiency Act of 1991 (ISTEA) for the installation of air bags in all

passenger cars and light trucks, the number of air bags in vehicles on

the road will increase each year. As a result, the annual number of

lives saved by air bags will continue to increase each year. Based on

current levels of effectiveness, air bags will save more than 3,200

lives each year in passenger cars and light trucks when all light

vehicles on the road are equipped with dual air bags. This estimate is

based on current seat belt use rates (about 69 percent, according to

State-reported surveys).

While air bags are saving large numbers of people in moderate and

high speed crashes, they sometimes cause fatalities, especially to

children, in lower speed crashes. As of June 1, 1998, NHTSA's Special

Crash Investigation program had confirmed a total of 105 crashes in

which the deployment of an air bag resulted in fatal injuries. Sixty-

one of those fatalities involved children. Four adult passengers have

also been fatally injured. Forty drivers are known to have been fatally

injured.

Just as the number of lives saved per year will rise as more

vehicles are

[[Page 49963]]

equipped with air bags, so will the number of fatalities caused by air

bags, absent either advanced air bags or changes in occupant behavior.

Using the year 2000 as a point of reference, if all passenger vehicles

on the road were equipped with air bags, air bags would save 3,215

lives annually. However, there would be 214 fatalities annually--33

infants in rear facing child seats, 129 other children, 41 drivers, and

11 adult passengers.

It is important to note that these estimates are based on pre-model

year 1998 air bags and on the assumption that there are no changes in

occupant demographics, driver/passenger behavior, belt use, child

restraint use, or the percent of children sitting in the front seat.

However, as noted above, changes have already occurred that have

reduced the potential number of fatalities. Manufacturers redesigned

most air bags for model year 1998 to reduce the adverse effects of air

bags. Moreover, additional changes are anticipated. As public education

programs succeed in creating better awareness of occupant safety

issues, and as auto manufacturers voluntarily continue to improve their

air bags, the potential adverse effects of air bags will be further

reduced. Nonetheless, the agency believes that the air bag fatalities

that have occurred to date, and the potentially much larger number of

air bag fatalities that could occur when all light vehicles are

equipped with air bags, demonstrate the need for regulatory action in

this area.

b. Causes of air bag fatalities. Air bag fatalities are caused by a

combination of proximity to deploying air bags and the current designs

of those air bags. The one fact that is common to all persons who died

is not their height, weight, gender, or age. Instead, it is the fact

that they were too close to the air bag when it started to deploy. For

some, this occurred because they were initially sitting too close to

the air bag. More often, this occurred because they were not restrained

by seat belts or child safety seats and were thrown forward during pre-

crash braking.

Air bags are designed to save lives and prevent injuries by

cushioning occupants as they move forward in a frontal crash. They keep

an occupant's head, neck, and chest from hitting the steering wheel or

instrument panel. To accomplish this, an air bag must move into place

quickly. The force of a deploying air bag is greatest as the air bag

begins to inflate. The force decreases as the air bag inflates further.

Occupants who are very close to or in contact with the cover of a

stored air bag when the air bag begins to inflate can be hit with

enough force to suffer serious injury or death. In general, a driver

can avoid this risk by sitting at least 10 inches away from the air bag

(measured from the breastbone to the center of the air bag cover) and

wearing safety belts. Teenage and adult passengers can avoid this risk

by moving their seat back and wearing their safety belts. Children

should ride in the rear seat whenever possible.

The confirmed fatalities involving children have a number of fairly

consistent characteristics. First, 13 infants were in rear-facing

infant seats that were installed in front of a passenger side air bag.

Second, the vast majority of the older children were not using any type

of restraint.11 Third, as noted above, the crashes occurred

at relatively low speeds. If the passenger air bag had not deployed in

those crashes, the children would probably not have been killed or

seriously injured. Fourth, the infants and older children were very

close to the instrument panel when the air bag deployed. A rear-facing

infant seat which is installed in the front seat of a vehicle with a

passenger side air bag will always position the infant's head very

close to the air bag. For essentially all of the older children, the

non-use or improper use of occupant restraints or the failure to use

the restraints most appropriate to the child's weight and age, in

conjunction with pre-impact braking, resulted in the forward movement

of the children prior to the actual crash. As a result, they were very

close to the air bag when it deployed. Because of their proximity, the

children sustained fatal head or neck injuries from the deploying

passenger air bag.

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\11\ 39 of the 48 forward-facing children who were fatally

injured by air bags were not using any type of belt or other

restraint. The remaining children included some who were riding with

their shoulder belts behind them and some who were wearing lap and

shoulder belts but who also should have been in booster seats

because of their small size and weight. Booster seat use could have

improved shoulder belt fit and performance. These various factors

and pre-crash braking allowed the children to get too close to the

air bag when it began to inflate.

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

factor regarding the confirmed adult deaths has been their proximity to

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

proximity was failure to use seat belts. Only 11 of the 40 drivers were

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

of the crash. As in the case of children, the deaths of drivers have

occurred primarily in low speed crashes.

The other cause of air bag fatalities is the design of current air

bags. Air bag fatalities are not a problem inherent in the concept of

air bags or in the agency's occupant restraint standard. That standard

has always permitted, but not required, vehicle manufacturers to use a

variety of design features that would reduce or eliminate the

fatalities that have been occurring, e.g., higher deployment thresholds

that will prevent deployment in low speed crashes, sensors that adjust

the deployment threshold depending on whether the occupant is

belted,12 different folding patterns and aspiration designs,

dual stage inflators,13 new air bag designs like the Autoliv

``Gentle Bag'' that deploys first radially and then toward the

occupant, and advanced air bags that either adjust deployment force or

suppress deployment altogether in appropriate circumstances. While some

of these features are new or are still under development, others have

been around (at least conceptually) for more than a decade. The agency

identified a number of these features in conjunction with its 1984

decision concerning automatic occupant protection and noted that

vehicle manufacturers could choose among those features to address the

problems reported by those manufacturers concerning out-of-position

occupants.

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\12\ For example, Mercedes-Benz offers passenger air bags whose

deployment threshold is 12 mph if the passenger is unbelted and 18

mph if the passenger is belted.

\13\ The passenger-side air bags installed in approximately

10,000 GM cars in the 1970's were equipped with dual stage

inflators. Today, for example, Autoliv, a Swedish manufacturer of

air bags, has a ``gas generator that inflates in two steps, giving

the bag time to unfold and the vent holes to be freed before the

second inflation starts. Should the bag then encounter an occupant,

any excessive gas--and indeed bag pressure--will exit through the

vent holes.''

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Although Standard No. 208 permits vehicle manufacturers to install

air bags incorporating those advanced features, very few current air

bags do so. Instead, vehicle manufacturers have thus far used designs

that inflate with the same force under all circumstances. Although the

vehicle manufacturers are now working to incorporate advanced features

in their air bags, the introduction of air bags with those features is

only just beginning.

Partly in view of the lead time needed to incorporate those

advanced features, vehicle manufacturers first took the quicker step of

depowering their air bags. Under a recent temporary amendment to

Standard No. 208, vehicle manufacturers have expedited their

introduction of depowered or otherwise redesigned air bags. While these

modified air bags will reduce, but not eliminate, the incidence of air

bag-

[[Page 49964]]

caused deaths, they still deploy with the same force in all crashes,

regardless of severity, and regardless of occupant weight or location.

Many manufacturers introduced substantial numbers of these less

powerful air bags in model year 1998.

2. Air Bag Requirements

Today's air bag requirements evolved over a 25-year period. NHTSA

issued its first public notice concerning air bags in the late 1960's.

Although vehicle manufacturers began installing air bags in 1986, it

was not until the fall of 1996 that manufacturers were first required

to install air bags in any motor vehicles.14

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\14\ Air bag firsts--In view of the confusion evident in some

public comments in recent rulemakings and even in some media

accounts about when air bags were first required, and by whom, the

agency has set forth a brief chronology below:

1972 First year in which vehicle manufacturers had the

option of installing air bags in passenger cars as a means of

complying with Standard No. 208. Prior to that year, vehicle

manufacturers had to comply means of installing manual lap and

shoulder belts. GM installed driver and passenger air bags in

approximately 10,000 passenger cars in the mid-1970's.

1986 First year in which vehicle manufacturers no

longer had the option of installing manual belts and were required

instead to install some type of automatic protection (either

automatic belts or air bags) in some passenger cars. This

requirement was issued by Secretary Dole in 1984. At the time of

that issuance, the agency expressly noted that vehicle manufacturers

had expressed concerns about air bags and out-of-position occupants.

In response to those concerns, NHTSA identified a variety of

technological remedies whose use was permissible under the Standard.

Between 1986 and 1996, vehicle manufacturers chose to comply with

the automatic protection requirements by installing over 35 million

driver air bags and over 18 million passenger air bags in passenger

cars. Another 12 million driver air bags and almost 3 million

passenger air bags were installed in light trucks in that same time

period.

1996 First year in which vehicle manufacturers were

required to install air bags in some passenger cars. This

requirement was mandated by the 1991 Intermodal Surface

Transportation Efficiency Act of 1991.

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

When the requirements for automatic protection (i.e., protection by

means that require no action by the occupant) were adopted in 1984 for

passenger cars, they were expressed in broad performance terms that

provided vehicle manufacturers with choices of a variety of methods of

providing automatic protection, including automatic belts and air bags.

Further, the requirements gave vehicle manufacturers broad flexibility

in selecting the performance characteristics of air bags. Later, those

requirements were extended to light trucks. While vehicle manufacturers

initially installed automatic belts in many of their vehicles,

ultimately, strong market preference for air bags led manufacturers to

move toward installing them in all of their passenger cars and light

trucks.

In 1991, Congress included a provision in 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. ISTEA

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 were phased in for light trucks

one year later.15 The final rule implementing this provision

of ISTEA was published in the Federal Register (58 FR 46551) on

September 2, 1993.

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

\15\ 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 are

performance requirements. The standard does not specify the design of

an air bag. Instead, when tested under specified test conditions,

vehicles must meet specified limits for injury criteria, including

criteria for the head, chest and thighs, measured on 50th percentile

male test dummies. Until recently, these criteria limits had to be met

for air bag-equipped vehicles in barrier crashes at speeds up to 48 km/

h (30 mph), both with the dummies belted and with them unbelted.

However, on March 19, 1997, the agency published a final rule

temporarily amending Standard No. 208 to provide the option of testing

air bag performance with an unbelted dummy in a sled test incorporating

a 125 millisecond standardized crash pulse instead of in a vehicle-to-

barrier crash test. This amendment was made primarily to expedite

manufacturer efforts to reduce the force of air bags as they deploy.

Standard No. 208's current automatic protection requirements, like

those established 14 years ago in 1984, apply to the performance of the

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

vehicle equipment. The broad vehicle performance requirements permit

vehicle manufacturers to ``tune'' the performance of the air bag to the

specific attributes of each of their vehicles.

The Standard's requirements also permit manufacturers to design

seat belts and air bags to work together. Before air bags, seat belts

had to do all the work of restraining an occupant and reducing the

likelihood that the occupant will strike the interior of the vehicle in

a frontal crash. Another consequence of not having air bags was that

vehicle manufacturers had to use relatively rigid and unyielding seat

belts that can concentrate a lot of force along a narrow portion of the

belted occupant's body in a serious crash. This concentration of force

created a risk of bone fractures and injury to underlying organs. The

presence of an air bag increases the vehicle manufacturer's ability to

protect belted occupants. Through using force management devices, such

as load limiters, a manufacturer can design seat belts to extend or

release additional belt webbing before the belts concentrate too much

force on the belted occupant's body. When these new belts stretch or

extend, the deployed air bag is there to prevent the belted occupant

from striking the vehicle interior.

Further, as noted above, Standard No. 208 permits, but does not

require, vehicle manufacturers to design their air bags to minimize the

risk of serious injury to unbelted, out-of-position occupants,

including children and small drivers. The standard gives the

manufacturers significant freedom to select specific attributes to

protect all occupants, including attributes such as (1) the crash

speeds at which the air bags deploy, (2) the force with which they

deploy, (3) air bag tethering and venting to reduce inflation force

when a deploying air bag encounters an occupant close to the steering

wheel or the instrument panel, (4) the use of sensors to both detect

the presence of rear-facing child restraints and the presence of small

children and prevent air bag inflation, (5) the use of sensors to

detect occupant position and prevent air bag inflation if appropriate,

and (6) the use of multi-stage versus single stage inflators. Multi-

stage inflators enable air bags to deploy with lower force in low speed

crashes, the type of crashes in which children and drivers have been

fatally injured, and with more force in higher speed crashes.

C. Comprehensive Agency Plan To Address Air Bag Fatalities

In late November 1996, NHTSA announced that it would be

implementing a comprehensive plan of rulemaking and other actions

(e.g., consumer education and encouragement of State seat belt use laws

providing for primary enforcement of their requirements) addressing the

adverse

[[Page 49965]]

effects of air bags.16 While there is a general consensus

that the best approach to preserving the benefits of air bags while

preventing air bag fatalities will ultimately be the introduction of

advanced air bag systems, those air bags are not immediately available.

Accordingly, the agency has focused on rulemaking and other actions to

help reduce the adverse effects of air bags in existing vehicles as

well as in vehicles produced during the next several model years. The

actions which have been taken, or are being taken, include the

following:

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\16\ For a discussion of the actions taken by NHTSA before

November 1996 to address the adverse effects of air bags, see pp.

40787-88 of the agency's NPRM published August 6, 1996 (61 FR

40784).

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

1. Interim Rulemaking Solutions

a. Existing and future vehicles-in-use. On November 11, 1997, NHTSA

published in the Federal Register (62 FR 62406) a final rule exempting,

under certain conditions, motor vehicle dealers and repair businesses

from the ``make inoperative'' prohibition in 49 U.S.C. Sec. 30122 by

allowing them to install retrofit manual on-off switches for air bags

in vehicles owned by people whose request for a switch is authorized by

NHTSA. The purpose of the exemption is to preserve the benefits of air

bags while reducing the risk that some people have of being seriously

or fatally injured by current air bags. The exemption also allows

consumers to have new vehicles retrofitted with on-off switches after

the purchase of those vehicles. It does not, however, allow consumers

to purchase new vehicles already equipped with on-off switches.

(Another rule, discussed below, allows manufacturers to ``factory

install'' manual on-off switches for vehicles with no, or small, rear

seats.)

b. New vehicles. 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 improved labels were required on new vehicles

beginning February 25, 1997, and were 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, an existing

provision in Standard No. 208 permitting vehicle manufacturers to offer

manual on-off 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 March 19, 1997, NHTSA published in the Federal Register (62 FR

12960) a final rule temporarily amending Standard No. 208 to facilitate

efforts of vehicle manufacturers to depower their air bags quickly so

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

broad flexibility already provided by the standard's existing

performance requirements, provided the vehicle manufacturers maximum

flexibility to quickly reduce the adverse effects of current air bags.

Vehicle manufacturers provided air bags that were depowered or

otherwise redesigned for a large number of model year 1998 vehicles.

2. Longer-Term Rulemaking Solution

In today's notice, NHTSA is proposing to require advanced air bags.

The agency is proposing new performance requirements to improve

occupant protection for occupants of different sizes, belted and

unbelted, while minimizing the risk to infants, children, and other

occupants from injuries and deaths caused by air bags.

3. Educational Efforts; Child Restraint and Seat Belt Use Laws

In addition to taking these actions, and conducting extensive

public education efforts, the Department of Transportation announced in

the spring of 1997 a national strategy to increase seat belt and child

seat use. Higher use rates would decrease air bag fatalities and the

chance of adverse safety tradeoffs occurring as a result of turning off

air bags. The plan to increase seat belt and child seat use has four

elements: stronger public-private partnerships; stronger State seat

belt and child seat use laws (e.g., laws providing for primary

enforcement of seat belt use requirements); active, high-visibility

enforcement of these laws; and effective public education. Substantial

benefits could be obtained from achieving higher seat belt use rates.

For example, if observed belt use increased from 69 percent to 90

percent, an estimated additional 5,400 lives would be saved annually

over the estimated 10,414 lives currently being saved by seat belts. In

addition, an estimated 129,000 injuries would be prevented annually.

The economic savings from these incremental reductions in both

fatalities and injuries would be $8.5 billion annually.

V. Technological Opportunities

The air bag suppliers and vehicle manufacturers are working on a

wide range of advanced technologies to upgrade air bag system

performance, including but not limited to addressing adverse effects of

air bags to out-of-position occupants. To illustrate the kinds of

technological opportunities that are available, NHTSA is including a

discussion on this subject presented by JPL in the Executive Summary of

its Advanced Air Bag Technology Assessment. For additional information,

interested persons are referred to the full JPL report, NHTSA's

Preliminary Economic Assessment for this proposal and the references it

cites, and the docket for this and other notices relating to Standard

No. 208.

The JPL Executive Summary includes the following discussion of

technological opportunities (section numbers are omitted):

Model year 2001. The technologies that are being developed and that

may be available for model year 2001 provide both improved information

and improved response. 17

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\17\ NHTSA notes that JPL, in identifying and analyzing

parameters to reflect the functions that may be required of advanced

technology, classified those parameters by the information provided

about the crash and the occupants and the air bag system response.

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

Information

Crash sensor/control systems with improved algorithms will

better discriminate when air bag deployment is necessary for occupant

crash protection, will provide better threshold control, and will

determine the appropriate inflation level for two-stage inflators.

Belt use status sensors can detect when an occupant is

belted so that the air bag deployment threshold can be raised when

belts are in use. (These are currently in use in some cars.)

Seat position sensors provide an approximate surrogate

measure of occupant size and proximity to the air bag module. They can

be used in combination with belt status sensors to determine the

appropriate inflator output.

Seat belt spool-out sensors could provide additional

information about an occupant's size and proximity to the air bag

module. These sensors were not mentioned as being part of any current

industry use strategy and therefore may not be available by model year

2001.

Static proximity (occupant position) sensors could

identify occupants in the keep-out zone, but will be available only if

an aggressive development program is

[[Page 49966]]

undertaken. They would not reduce injuries to all out-of-position

occupants, and they could be ``fooled'' some of the time.

Response

Automatic suppression can prevent inflation when sensors

determine that an ccupant is in a keep-out zone where injuries could

occur.

Two-stage inflators can permit relatively soft inflation

for crashes of lower threshold velocity, and full inflation when

necessary for crashes of high threshold velocity.

Compartmented air bags, radial deployments, and bags with

lighter-weight fabrics may reduce the size of the keep-out zone.

Advanced belts can improve restraint system safety and

protectiveness. They may include pretensioners that can provide better

coupling of the occupant to the seat for improved ride-down during the

crash. Also, they can, to some degree, limit occupant proximity to the

air bag module. Load limiters can also improve belt performance by

reducing maximum belt loads on the occupant. (Pretensioners and load

limiters are currently in some vehicles.)

Model year 2003. By model year 2003, there could be evolutionary

changes in some of the systems and the possibility of the introduction

of occupant and proximity sensors.

Information

Crash sensor/control system algorithms will continue to be

improved.

Belt use sensors will be widely used already.

Integrated occupant and proximity sensors could be

available that would identify occupants in the keep-out zone or those

who would enter it.

Precrash sensors may be available, but their application

requires further investigation.

Response

Automatic suppression to prevent inflation will be

available for use with proximity sensors.

Multistage inflators to provide more tailored responses

for a variety of occupants and crash severities could be available, if

needed.

Bag designs will continue to be improved, permitting a

reduction of the keep-out zone.

Pretensioners and load limiters will be placed in

increasing numbers of vehicles. Air belts will be available to improve

safety belt effectiveness.

NHTSA notes that the JPL report presents tables listing specific

technologies for advanced safety restraint systems and providing a

summary of advanced technology characteristics. The technology items

discussed in the JPL report include:

Sensors

--Pre-Crash Sensing

--Crash Severity Sensors

--Sensing Diagnostic Modules/Crash Algorithms

--Belt Use Sensors

--Belt Spool-Out Sensors

--Seat Position Sensors

--Occupant Classification Sensors

--Occupant Proximity Motion Sensors

--Computational Systems/Algorithms

Inflators

--Non-Azide Propellants

--Hybrid Inflators

--Heated Gas Inflators

--Multistage Inflators

--Inflators With Tailorable Mass Flow Rate

Air Bags

--New Fabrics and Coatings

--New Woven Fabrics and Bag Construction

--New Bag Shapes and Compartmented Bags

--New Air Bag Venting Systems

Seat Belt Systems

--Pretensioners

--Load Limiting Devices

--Inflatable Seat Belts

The JPL report also presents an assessment of the merits of advanced

technologies.

The JPL report cautioned that expected improvements in the safety

and protectiveness of air bags must be tempered by the understanding

that there are key technology developments that need to be

accomplished, namely:

Air bag deployment time variability must be reduced by

improvements in the vehicle crush/crash sensor system.

Inflator variability must be reduced so that dual-stage

inflators can be applied effectively.

System and component reliability must receive diligent

attention to achieve the high levels required under field conditions.

Occupant sensors must be developed that can distinguish

with high accuracy small, medium, and large adults; children; and

infant seats.

Position sensors to measure occupant proximity to the air

bag module with the required response time and accuracy must be

demonstrated.

The JPL report noted that all of the above are the subject of

current development, but development, test, and integration of the

advanced technologies needs to be accelerated to enable their

incorporation into production vehicles.

The JPL report also notes that its projections of technology

availability are based on limited contacts with a limited number of

vehicle manufacturers and suppliers, and that the state of the art of

advanced air bag technologies is in a high state of flux. The report

notes that the projected technologies, as well as other technologies,

may advance more or less rapidly than indicated.

NHTSA has had more extensive contacts than JPL with suppliers and

vehicle manufacturers, and more recent ones. Based on confidential

information shared with the agency during those contacts, NHTSA

believes that the JPL report is conservative in its assessment of the

stages that some suppliers have reached in developing new technologies

and the model year in which some of the very highly advanced air bag

designs will first be introduced.

NHTSA recognizes, however, that different suppliers and vehicle

manufacturers are at different stages in their development of advanced

air bags, and also face different constraints and challenges, e.g.,

different states-of-the-art of their current air bag systems,

engineering resources, number of vehicles for which air bags need to be

redesigned, etc. The agency believes the proposed date for the

beginning of the phase-in, the phase-in itself, and also the proposal

of a number of manufacturer options to reflect different available

design choices, would accommodate these differing situations.

VI. Proposal for Advanced Air Bags

A. Introduction

NHTSA's goals in this rulemaking are to enhance the benefits of air

bags for all occupants while eliminating or minimizing risks from air

bags, and to ensure that the needed improvements in occupant protection

are made expeditiously, and in accordance with the recently adopted

statutory deadlines. As discussed in the preceding section of this

notice, the vehicle manufacturers and their suppliers are already

pursuing a wide variety of technological opportunities that can be used

to achieve these goals.

The sheer number and variety of available technological

opportunities creates special challenges from a regulatory perspective.

While the availability of multiple technologies generally makes it

easier to solve the current problems with air bags quickly, it also

means that the agency must take special care to ensure that the

regulatory language it adopts will not be unnecessarily design-

restrictive.

Among other things, the agency wishes to avoid:

Inadvertently preventing the use of superior air bag

designs;

[[Page 49967]]

Favoring one viable technology or design over another,

where either would meet the need for safety;

Requiring an expensive solution, where an inexpensive one

will work; or

Requiring implementation of a particular technology before

it can be appropriately developed.

In seeking to ensure that its proposal is not unnecessarily design-

restrictive, the agency has sought to develop requirements that are as

performance-oriented as possible, and to include manufacturer options

that accommodate for the kinds of technological solutions that the

agency knows are under development.

Moreover, since the ultimate question for regulators, industry, and

the public is how the required safety features will work in the real

world, NHTSA has sought to specify test procedures that most closely

replicate the real world conditions that affect the possibility of

traffic deaths and injuries.

As a result, NHTSA is proposing to require manufacturers to meet

improved performance criteria in additional tests using a wider array

of test dummies. The existing and proposed tests are identified in

Figures 1 and 2, below. Figure 1 shows tests for requirements to

preserve and improve occupant protection for different size occupants,

belted and unbelted. Figure 2 shows tests for requirements to minimize

the risk to infants, children, and other occupants from injuries and

deaths caused by air bags.

BILLING CODE 4910-59-P

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[GRAPHIC] [TIFF OMITTED] TP18SE98.000

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[GRAPHIC] [TIFF OMITTED] TP18SE98.001

BILLING CODE 4910-59-C

[[Page 49970]]

NHTSA notes that, in the future, it expects to propose a higher

speed frontal offset test requirement and also is considering proposing

one or more tests using 95th percentile adult male dummies. The agency

is not proposing a higher speed frontal offset test requirement at this

time because it is still conducting research regarding such a

requirement. 18 The agency is not proposing tests using 95th

percentile adult male dummies at this time because the development of

that dummy is not expected to be completed until sometime next year.

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\18\ For information concerning the agency's research program,

interested persons are referred to the agency's Report to Congress,

Status Report on Establishing a Federal Motor Vehicle Safety

Standard for Frontal Offset Crash Testing, April 1997. This report

is available on NHTSA's web site. The address for the section of the

web site where this report is located is ``http://www.nhtsa.dot.gov/

cars/rules/CrashWorthy/''.

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Under the proposed performance requirements identified in Figures 1

and 2, vehicle manufacturers would be required to show that the air

bags in their vehicles provide protection to small stature occupants as

well as to average size males, and to adopt one or more of a number of

available design features that will minimize the risk caused by air

bags to infants in rear-facing child restraints, out-of-position

children, or other out-of-position occupants in low speed crashes.

The test matrix identified in Figures 1 and 2 represents a natural

evolution and refinement of Standard No. 208's current requirements.

The agency has always sought to include in the standard test procedures

that replicate the real world factors that affect the possibility of

traffic deaths and injuries. This is the best way to ensure that

required safety features will perform well not only in compliance

tests, but also in the real world.

Among other things, the agency has long specified full scale

vehicle crash tests using instrumented dummies because it is only

through such tests that the protection provided by a vehicle and its

occupant protection system can be fully measured. Different vehicle

models have different crash pulses. The results of crash tests reflect

not only the performance of the air bag, but how a particular vehicle

model crumples and absorbs energy in a crash, i.e., its individual

crash pulse. The use of crash tests necessitates that vehicle

manufacturers take into account the crash pulse of their vehicles, the

air bag design, occupant compartment design features, seat belt design

(for belted tests) and specific attributes of each of their subsystems.

Also, the agency has long included tests for air bag-equipped

vehicles using both belted and unbelted dummies, since a large number

of occupants in the United States continue to ride unbelted. Even

today, nearly half of all occupants in potentially fatal crashes do not

wear their seat belts. Teenagers are particularly likely to ride

unbelted.

Moreover, the Standard has long included test conditions that

replicate a variety of different types of crashes. Of particular note,

the standard's longstanding barrier test requirements specify crash

tests at any speed up to and including 48 km/h (30 mph), and at a range

of impact angles.

NHTSA has also always sought to maximize manufacturer flexibility

in providing effective occupant protection. As the agency has stated

many times, Standard No. 208 has never specified the design of an air

bag. Manufacturers have been free to design their air bags in any

manner they like, e.g., any size, any inflation level, etc. so long as

the standard's injury criteria limits are not exceeded in specified

crash tests.

Today's proposal follows these longstanding practices by proposing

to add new tests that replicate additional real world factors that

affect the possibility of deaths and injuries which are not directly

addressed by the standard's current requirements. Manufacturers would

continue to be permitted maximum design freedom in designing their air

bags, so long as the standard's injury criteria performance limits are

met in specified tests.

Manufacturers can use many different technologies and designs to

meet the proposed requirements. One approach is for manufacturers to

develop air bags that inflate in a manner that does not cause injuries

to out-of-position occupants. Several air bag suppliers have recently

demonstrated air bags that incorporate improved folding patterns and

internal tethering and venting to reduce the risk of injury to out-of-

position occupants. For example, Autoliv has demonstrated an

``umbrella'' air bag that deploys first radially and then toward the

vehicle occupant. It also may be possible to design air bags that use

vents or other means of preventing further deployment if the air bag is

blocked by the occupant during inflation. Again, under today's

proposal, manufacturers would be permitted flexibility in designing

their air bags as long as all of the standard's performance

requirements are met in specified tests.

A discussion of each of the specific proposed test requirements

follows, in the general order presented in Figures 1 and 2.

B. Existing and Proposed Test Requirements

1. Tests for Requirements To Preserve and Improve Occupant Protection

for Different Size Occupants, Belted and Unbelted

a. Safety of medium to large teenagers and adults. Standard No. 208

has long required vehicles to meet specified injury criteria, including

criteria for the head and chest, measured on 50th percentile adult male

test dummies during a rigid barrier crash test at any speed up to 48

km/h (30 mph) and over the range of angles from -30 degrees to +30

degrees. The standard has required air-bag-equipped vehicles to meet

the criteria both with the dummies belted and unbelted.

If a vehicle crash test is to measure the overall ability of a

vehicle and its occupant protection system to prevent fatalities and

serious injuries, the crash test must have the severity of a

potentially fatal crash. It is also important that the crash test make

it necessary for vehicle manufacturers to design and equip their

vehicles so that they provide protection in a range of potentially

fatal crashes, recognizing that no single type of crash test can be

directly representative of all the myriad potentially fatal crashes

that occur in the real world.

The longstanding barrier test requirement specified in Standard No.

208 simulates a wide range of potentially fatal crashes, both with

respect to severity and crash pulse. The test is conducted at any speed

up to 48 km/h (30 mph), meaning that protection must be provided at all

such speeds, e.g., 32 km/h (20 mph) and 40 km/h (25 mph), as well as 48

km/h (30 mph). The test is also conducted at any angle between 30

degrees to the left and 30 degrees to the right. While the

perpendicular rigid barrier test results in crash pulses of short

duration, e.g., the kind of pulse that a vehicle experiences when it

strikes a bridge abutment or fully engages another similar-sized or

larger vehicle directly head-on, the angled rigid barrier tests result

in crash pulses of longer duration, i.e., a softer crash pulse.

The rigid barrier test requirements have been an integral part of

the standard's automatic crash protection requirements and have

resulted in enormous savings of lives. As noted above, NHTSA estimates

that air bags have saved about 3,148 drivers and passengers. Of these,

2,725 were unbelted and 423 were belted. If these levels of

effectiveness are maintained, i.e., 21 percent in frontal crashes for

restrained occupants and 34 percent in

[[Page 49971]]

frontal crashes for unrestrained occupants, 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. Standard

No. 208's current requirements thus represent one of NHTSA's most

effective regulations in terms of the numbers of lives saved.

As also noted earlier in this notice, the agency amended Standard

No. 208 in March 1997 to provide a temporary option for manufacturers

to certify their vehicles to an unbelted sled test as an alternative to

the unbelted barrier test requirement. NHTSA established the sled test

option to ensure that the vehicle manufacturers could quickly depower

all air bags so that they inflate less aggressively.19 While

vehicle manufacturers could have depowered many or most of their

vehicles' air bags without changes to Standard No. 208, the final rule

expedited this process.

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\19\ The agency's initial steps regarding technological

solutions focused on depowering primarily because the lead time

needed for depowering was significantly shorter than the lead time

for the technological solutions that are the subject of this

proposal.

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Under the March 1997 final rule, the sled test option was scheduled

to terminate on September 1, 2001. The agency explained that there was

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 were various alternatives

already allowed by the standard to address the problem that did not

necessitate reducing the standard's performance requirements. While the

agency specified a several year duration for the alternative sled test,

it indicated that it would revisit the end date, to the extent

appropriate, in its future rulemaking on advanced air bags. See 62 FR

12968; March 19, 1997.

The September 1, 2001 termination date for the sled test option has

been superseded by the NHTSA Reauthorization Act of 1998. In a

paragraph titled ``Coordination of Effective Dates,'' the Act provides

that the unbelted sled test option ``shall remain in effect unless and

until changed by [the final rule for advanced air bags].'' The

Conference Report states that the current sled test certification

option remains in effect ``unless and until phased out according to the

schedule in the final rule.''

In light of the Act, the agency is proposing to phase out the sled

test option as the requirements for advanced air bags are phased in.

While NHTSA believes the sled test option has been an expedient and

useful temporary measure to ensure that the vehicle manufacturers could

quickly depower all of their air bags and to help ensure that some

protection would continue to be provided, the agency does not consider

sled testing to be an adequate long-term means of assessing the extent

of occupant protection that a vehicle and its air bag will afford

occupants in the real world. The sled test, first, excludes vehicle

factors that can significantly affect the level of protection received

in the real world and, second, is insufficiently representative of

potentially fatal real world crashes.

Unlike a full scale vehicle crash test, a sled test does not, and

cannot, measure the actual protection an occupant will receive in a

crash. The current sled test measures limited performance attributes of

the air bag, but cannot measure the performance provided by the vehicle

structure in combination with the air bags or even the full air bag

system by itself.

Among other shortcomings, the sled test does not evaluate the

actual timing of air bag deployment. Deployment timing is a critical

component of the safety afforded by an air bag. If the air bag deploys

too late, the occupant may already have struck the interior of the

vehicle before deployment begins.

Air bag timing is affected by parts of the air bag system which are

not tested during a sled test, i.e., the crash sensors and computer

crash algorithm. A barrier crash test evaluates the ability of sensors

to detect a crash and the ability of an algorithm to predict, on the

basis of initial sensing of the rate of increase in force levels,

whether crash forces will reach levels high enough to warrant

deployment. However, the sled test does not evaluate these critical

factors. The ability of an algorithm to correctly, and quickly, predict

serious crashes is critical. The signal for an air bag to deploy must

come very early in a crash, when the crash forces are just beginning to

be sensed by the air bag system. A delay in an air bag's deployment

could mean that the air bag deploys too late to provide any protection.

In a sled test, the air bag is artificially deployed at a predetermined

time. The time of deployment in a sled test is artificial and may

differ significantly from the time when the air bag would deploy during

an actual crash involving the same vehicle.

Second, the current generic sled pulse does not replicate the

actual crash pulse of a particular vehicle model, i.e., the specific

manner in which the front of the vehicle deforms during a crash,

thereby absorbing energy. The actual crash pulse of a vehicle is a

critical factor in occupant protection. A crash pulse affects the

timing of air bag deployment and the ability of an air bag to cushion

and protect an occupant. However, the current sled test does not use

the crash pulse of the vehicle being tested. In many cases, the crash

pulse used in the sled test is not even one approximately

representative of the test vehicle. The sled test uses the crash pulse

of a large passenger car for all vehicles, regardless of their type or

size. This crash pulse is appropriate for large passenger cars, but not

for light trucks and smaller cars since they typically have much

``stiffer'' crash pulses than that of the sled test. In the real world,

deceleration of light trucks and smaller cars, and their occupants,

occurs more quickly than is simulated by the sled test. Thus, the sled

test results may overstate the level of occupant protection that would

be provided by a vehicle and its air bag system in the real world. An

air bag that can open in a timely fashion and provide adequate

cushioning in a soft pulse crash may not be able to do so in a stiffer

pulse crash. This is because an occupant of a crashing vehicle moves

forward, relative to the vehicle, more quickly in stiffer pulse crash

than in a softer pulse crash.

Third, a sled test does not measure the potential for harm from

vehicle components that are pushed back into the occupant compartment

during a crash. Examples of components that may intrude into the

occupant compartment include the steering wheel, an A-pillar and the

toe-board. Since a sled test does not involve any kind of crash or

deformation of the vehicle, it implicitly assumes that such intrusion

does not occur in crashes. Thus, the sled test may indicate that a

vehicle provides good protection when, as a result of steering wheel or

other intrusion in a real world, the vehicle will actually provide poor

protection in a real world crash.

Fourth, the sled test does not measure how a vehicle performs in

angled crashes. It only tests vehicles in a perpendicular crash. In the

real world, frontal crashes occur at varying angles, resulting in

occupants moving toward the steering wheel and instrument panel in a

variety of trajectories. The specification of angled tests in

conjunction with the barrier test requirement ensures that a vehicle is

tested under these real world conditions.

As noted below in the appendix to this preamble, NHTSA received

several petitions for reconsideration concerning the sled test's sunset

date (subsequently superseded by the NHTSA Reauthorization Act of

1998). The

[[Page 49972]]

agency notes that its proposal to phase the option out as the

requirements for advanced air bags are phased in will provide

additional time for the vehicle manufacturers to redesign their air

bags to avoid causing harm and to provide improved protection for all

occupants, belted and unbelted. In the appendix, the agency provides

additional reasons supporting its proposal for terminating the sled

test option, including a discussion of the importance for safety of

maintaining effective unbelted frontal crash test requirements.

NHTSA is requesting comments on whether it should develop potential

alternative unbelted crash test requirements. The auto industry and

other parties have raised a number of objections to the existing

unbelted barrier test requirements. NHTSA is willing to consider

alternatives and to that end is placing a technical paper on this

subject in the docket. Among other things, the paper compares the

existing rigid barrier test to tests using a stationary deformable

barrier and a movable deformable barrier.

With respect to the current barrier test requirements, and as

discussed later in this notice in a section titled ``Injury Criteria,''

the agency is proposing to upgrade the standard's chest injury criteria

and to add neck injury criteria. NHTSA notes that, as part of

developing this proposal for advanced air bags, it considered the

latest available information concerning injury criteria for both the

existing 50th percentile adult male dummy and for each of the proposed

new dummies. The agency is placing in the public docket a technical

paper which explains the basis for each of the proposed injury criteria

and the proposed performance limits.

NHTSA is also proposing to include, for all crash tests specified

by Standard No. 208, certain vehicle integrity requirements. These

requirements would specify that vehicle doors may not open during the

crash test. For many years the agency has monitored whether doors open

during 30 mph frontal barrier crash tests. In the agency's experience,

doors remain closed in these crash tests. Since vehicles already can

and do comply with this requirement, this proposal would establish this

norm as a minimum level of safety. This requirement would support the

agency goal of mitigating the fatalities and serious injuries

attributable to complete and partial ejections.

This proposal would also specify that, after crash testing,

vehicles having a roof of rigid construction (i.e., vehicles other than

convertibles), must meet the following requirements. It must be

possible, without the use of tools, to open at least one door, if there

is one, per each row of seats. Further, where there is no such door, it

must be possible to move the seats or tilt their backrests as necessary

to allow the evacuation of all the occupants. This post crash door

opening check has always been a demonstration part of the agency's

compliance test procedure. The purpose is to demonstrate the potential

for entrapment. After each test, the technicians approach the vehicle

and try to open the vehicle doors. In the majority of these full

frontal crash tests conducted by the agency, the technicians are able

to open the vehicle doors without the use of tools. This process is

recorded on the test films. The agency is proposing to add this door

opening requirement to the regulation. NHTSA does not have any

information indicating that there would anything other than a minimal

cost impact associated with this proposed requirement, but requests

comments on this issue.

b. Safety of small teenagers and small adults. Another part of the

agency's proposal that is intended to enhance the benefits of air bags

is to require vehicles to meet performance requirements for 5th

percentile adult female dummies in the same tests long specified for

50th percentile adult male dummies.

Accordingly, the agency is proposing to require vehicles to meet

specified injury criteria, including criteria for the head, neck,

chest, and femurs, measured on 5th percentile adult female test dummies

during a rigid barrier crash test at any speed up to 48 km/h (30 mph)

and at the same range of angles applicable to the tests using 50th

percentile male dummies. Under the proposal, vehicles must meet the

criteria both with the dummies belted and unbelted.

Certain of the proposed injury criteria differ from those specified

or proposed for 50th percentile adult male dummies to reflect the

different injury risks faced by 5th percentile adult females. Dummy

seating positions are also adjusted to reflect 5th percentile adult

females. The agency is proposing that tests be conducted with the

dummies seated in a full forward position. While many 5th percentile

adult females can sit further back, the proposed test will ensure that

protection is provided in a more extreme position, but one where air

bags can still provide protection.

NHTSA is proposing to specify the use of the Hybrid III 5th

percentile adult female dummy. The Society of Automotive Engineers has

guided the development of this dummy, and that work is nearly complete.

Therefore, the motor vehicle industry is familiar with this dummy.

NHTSA has not, however, yet proposed to add this dummy to Part 572, the

agency's regulation containing specifications for the various dummies

it specifies in the Federal motor vehicle safety standards. The agency

expects to propose adding the Hybrid III 5th percentile adult female

dummy to Part 572 later this year.\19\a

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\19\a The proposed rule to add Hybrid III 5th

percentile adult female dummy to Part 572 published in the Federal

Register September 3, 1998.

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NHTSA is also proposing one additional barrier test requirement

using 5th percentile adult female dummies, an up to 40 km/h (25 mph)

offset deformable barrier test requirement, using restrained dummies.

Research conducted by Transport Canada has shown that one of the

causes of adverse effects of air bags is late deployment of some air

bags in crashes with a ``soft crash pulse.'' In order to reproduce the

softer, longer duration crash pulse, it selected the 40 percent offset

barrier. It conducted crash tests into the barrier at 8 km/h (5 mph)

increments up to 40 km/h (25 mph). These tests were conducted with a

5th percentile adult female belted dummy in a full-forward position, to

simulate short stature drivers and the high belt use pattern in Canada.

It found that at 40 km/h (25 mph), all the air bag systems of the

vehicles tested would deploy. It also found that even for a belted

driver, the deployment of the air bag frequently was so late that the

test dummy would be right on the steering wheel, a ``worst case''

condition. The test procedure was shown to be a good test for the head,

neck and chest loading on the dummy by the air bag.

NHTSA notes that the timing of air bag deployment is determined by

a vehicle's crash sensing system, including both the crash sensing

hardware and associated computer algorithm, i.e., the software. The

decision to deploy an air bag is necessarily predictive, that is, the

decision that a crash will be severe enough to warrant air bag

deployment must be made very early in the crash if the air bag is to

deploy in time to provide protection. The work done by Transport

Canada, as well as other research, has indicated that the crash sensing

systems of some vehicles need to be improved to better evaluate some

crash pulses.

The agency is proposing a 40 km/h (25 mph) offset deformable

barrier crash test requirement to help ensure that vehicle

manufacturers upgrade their crash sensing and software systems, as

necessary, to better address soft crash pulses. The proposed test is

essentially

[[Page 49973]]

the one that Transport Canada has been conducting for purposes of

research. Restrained 5th percentile adult female dummies would be

positioned in the same full forward position being proposed for the

rigid barrier test discussed above, and the same injury criteria limits

would apply. Since this is a relatively low energy test, it should be

very easy to meet the injury criteria limits so long as the air bag

deploys early in the crash event before the dummy moves very far

forward.

Based on the testing conducted by Transport Canada, the problem of

late deployments appears to be a problem with only some vehicles, at

least in the environment measured in this particular crash test. The

agency expects that the problem can be solved using a number of readily

available approaches. These include improving computer algorithms, and

adding crash sensors, e.g., using extra sensors mounted in the crush

zone of the vehicle to provide additional, and earlier, information to

use in the decision making algorithm. A longer term means of ensuring

that air bags deploy early in a crash would be to use anticipatory

crash sensors.

The agency is also proposing specifications for the deformable

barrier to be used in this test. The specifications for this barrier

would be included in Part 587.

2. Tests for Requirements To Minimize the Risk to Infants, Children and

Other Occupants From Injuries and Deaths Caused by Air Bags

The one fact that is common to all persons who are at risk from air

bags is that they are extremely close to the air bag at time of

deployment. Behavioral changes, such as ensuring that children ride in

the back seat and that all occupants are properly restrained, can

sharply reduce the number of persons who are in such positions.

However, to minimize or eliminate air bag risks for the remaining

persons who may be close to the air bag at time of deployment, one of

two things must be done: either air bag deployment must be suppressed,

or the air bag must be designed to deploy in such a manner that it does

not cause a significant risk of injury to persons in such positions.

All of the technologies to minimize or eliminate air bag risks follow

one of these approaches.

As NHTSA developed test requirements to minimize or eliminate air

bag risks, it needed to account for the fact that the persons who are

potentially at risk vary from infants to adults, and have different

potentials for injury. The agency therefore found it necessary to

develop requirements using a variety of test dummy sizes. Moreover,

since the agency wished to avoid requirements that are unnecessarily

design-restrictive, it was necessary to develop a variety of

manufacturer options that account for the kinds of effective

technological solutions that the agency knows are under development.

Each of the test requirements being proposed by the agency is

discussed below.

a. Safety of infants. Infants in rear facing child seats are at

significant risk from deploying air bags, since the rear facing

orientation of the child seat places their heads extremely close to the

air bag cover. This is why NHTSA emphasizes that rear facing infant

seats must never be placed in the front seat unless the air bag is

turned off.

In order to address the risks air bags pose to infants in rear

facing child seats, NHTSA is proposing two alternative test

requirements, the selection of which would be at the option of the

manufacturer. The two manufacturer options are: (1) test requirements

for an automatic air bag suppression feature or (2) test requirements

for low-risk deployment involving deployment of the air bag in the

presence of a 12-month old Crash Restraints Air Bag Interaction (CRABI)

dummy in a rear facing child restraint.

If the automatic suppression feature option were selected, the air

bag would need to be suppressed during several static tests using, in

the right front passenger seat, a 12 month old child dummy in a rear

facing infant seat, and also during rough road tests. The rear facing

infant seat would be placed in a variety of different positions during

the static tests. In order to ensure that the suppression feature does

not inappropriately suppress the air bag for small statured adults, the

air bag would need to be activated during several static tests using a

5th percentile adult female dummy in the right front passenger seat,

and also during rough road tests using that dummy.

The agency is proposing rough road tests to address the possibility

that some types of automatic suppression features, e.g., weight

sensors, might be ``fooled'' by occupant movement associated with

riding on rough roads. For example, depending on the design of the

sensor, occupant movement such as bouncing might cause the weight

sensor to read a higher weight or lower weight. The agency believes

that such devices should be designed so they do not turn on the air bag

in the presence of a small child who is bouncing as a result of riding

on a rough road, and so that they do not turn off the air bag in the

presence of a small-statured adult who is bouncing as a result of

riding on a rough road.

If the automatic suppression feature option were selected, a

manufacturer would be required to provide a telltale light on the

instrument panel which is illuminated whenever the passenger air bag is

deactivated and not illuminated whenever the passenger air bag is

activated. This telltale would advise vehicle occupants of the

operational status of the air bag. In addition, the agency would use

the telltale to determine, during the tests discussed above, whether

the air bag is appropriately activated or deactivated.

If the low risk deployment option were selected, a vehicle would be

required to meet specified injury criteria when the passenger air bag

is deployed in the presence of a 12 month old child dummy placed in a

rear facing infant seat. The agency is proposing injury criteria

appropriate for a 12 month old child. In the case of air bags with

multiple inflation levels, the injury criteria would need to be met for

all levels.

NHTSA notes that there are uncertainties associated with all of the

injury criteria proposed by this notice, especially those for children.

Because experimental test data are generally not available from

children, it is necessary to estimate injury tolerances by other means,

e.g., by applying scaling methods to adult data. Particularly because

injury mechanisms may differ in some respects between adults and

children, there are necessarily some uncertainties associated with

injury criteria developed by these means.

NHTSA requests comments on how to take account of these

uncertainties in this rulemaking. For example, the agency is proposing

a HIC limit of 660 for the 12-month old CRABI dummy in a rear facing

child restraint. However, there are uncertainties as to how much risk

of injury is represented by this value. The agency requests commenters

to address the appropriateness of the proposed value, and on whether

the agency should permit a low risk deployment option or instead

require suppression for infants in rear facing child restraints.

With respect to that part of the proposed low risk deployment

option that would require injury criteria limits to be met for all

levels of a multi-level air bag, NHTSA notes that a child in a rear

facing infant seat would be extremely close to the passenger air bag in

any crash, regardless of crash severity. Moreover, based on discussions

with suppliers and vehicle manufacturers, the agency believes that the

development of technologies which

[[Page 49974]]

suppress the passenger air bag in the presence of a rear facing infant

seat is nearing completion. Thus, it appears reasonable to expect

advanced air bag designs to essentially eliminate risk of serious

injury or fatality resulting from air bag deployment to children in

rear facing infant seats. Of course, even with advanced air bags,

children in rear facing infant seats, like other children, will be

safer in the back seat.

Under both test procedures, manufacturers would be required to

assure compliance in tests using any child restraint capable of being

used in the rear facing position which was manufactured for sale in the

United States between two years and ten years prior to the date the

first vehicle of the model year carline of which the vehicle is a part

was first offered for sale to a consumer. This would ensure that

vehicle manufacturers take account of the variety of different rear

facing child restraints in use as they design their systems. The

restraints used for compliance testing could be unused or used;

however, if used, there could not be any visible damage prior to the

test. The agency requests comments on whether there are alternative

means of achieving this result, e.g., specifying use of several

representative devices.

NHTSA is proposing to specify use of the 12 month old CRABI dummy.

The motor vehicle industry is familiar with this dummy, and the agency

expects to propose adding it to Part 572 later this year.

b. Safety of 3-year-old children. Young children are at special

risk from air bags because, when unbelted, they are easily propelled

close to the air bag as a result of pre-crash braking. NHTSA strongly

recommends that young children ride in the back seat, which is a much

safer location whether or not a vehicle has air bags.

In order to address the risks air bags pose to young children who

do ride in the front seat, NHTSA is proposing requirements using both

3-year old and 6-year old child dummies. While there are both

similarities and overlap between the requirements using the different

dummies, the agency will discuss them separately (and cover them

separately in the proposed regulatory text) because a manufacturer

might choose to select different compliance options for the two

dummies.

As to 3-year-old child dummies, the agency is proposing four

alternative test requirements, the selection of which would be at the

option of the manufacturer. The four manufacturer options are: (1) test

requirements for an air bag suppression feature that suppresses the air

bag when a child is present, i.e., a weight or size sensor, (2) test

requirements for an air bag suppression feature that suppresses the air

bag when an occupant is out of position, (3) test requirements for low

risk deployment involving deployment of the air bag in the presence of

out-of-position 3-year old child dummies, and (4) full scale dynamic

out-of-position test requirements, which include pre-impact braking as

part of the test procedure.

NHTSA is proposing to specify use of the Hybrid III 3-year-old

child dummy. The motor vehicle industry is familiar with this dummy,

and the agency expects to propose adding it to Part 572 later this

year.

Requirements for an air bag suppression feature (weight or size

sensor) that suppresses the air bag when a child is present. These

requirements would mirror those being proposed with respect to a

suppression feature for infants in rear facing child seats. If this

option were selected, the air bag would need to be deactivated during

several static tests using, in the right front passenger seat, a 3-year

old child dummy, and also during rough road tests.

The child dummy would be placed in a variety of different positions

during the static tests. Because the effectiveness of such a feature

depends on the air bag being suppressed regardless of how a child may

be positioned, and given the ease of conducting such tests, the agency

is specifying a relatively large number of such positions. Some of the

positions specify placing the dummy in a forward-facing child seat or

booster seat.

In order to ensure that the suppression feature does not

inappropriately suppress the air bag for small statured adults, the air

bag would need to be activated during several static tests using a 5th

percentile adult female dummy in the right front passenger seat, and

also during rough road tests using that dummy. A manufacturer would

also be required to provide a telltale light on the instrument panel

which is illuminated whenever the passenger air bag is deactivated and

not illuminated whenever the passenger air bag is activated.

Test requirements for an air bag suppression feature that

suppresses the air bag when a child is out-of position. The agency

believes that a suppression feature that suppresses the air bag when an

occupant is out-of-position would need to be tested very differently

than one which suppresses the air bag whenever a child is present.

While various static and rough road tests can be used to determine

whether the latter type of suppression device is effective, they would

be of limited utility in testing a feature that suppresses the air bag

when an occupant is out of position. This is because one of the key

criteria in determining whether the latter type of suppression feature

is effective is whether it works quickly enough in a situation where an

occupant is propelled out of position as a result of pre-crash braking

(or other pre-crash maneuvers) before a crash. The agency has

accordingly developed separate test requirements for such devices.

If this option is selected by the vehicle manufacturer, the

manufacturer would be required to provide a telltale indicating whether

the air bag was activated or deactivated. Operation of the suppression

feature would be tested through the use of a moving test device which

would be guided toward the area in the vehicle where the air bag is

located.

This test device would begin its course of travel in a forward

direction toward a target area inside the vehicle. This target area,

the air bag suppression zone, consists of a portion of a circle

centered on the geometric center of the vehicle's air bag cover. The

function of the air bag suppression system would be tested through the

use of a headform propelled toward the air bag suppression zone at any

speed up to 11 km/h (7 mph)--equivalent to a typical speed that the

head of an occupant attains in pre-crash braking. When the test fixture

enters the area near the air bag--the air bag suppression zone--where

injuries are likely to occur if the air bag deploys, the telltale is

monitored to determine if the suppression feature has disabled the air

bag.

Apparatus that could be used to conduct this test would include a

pneumatically operated ram whose stroke is sufficient to propel a 165

mm (6.5 inch) headform from a point of origin to a point forward of the

automatic suppression plane of the test vehicle. Once activated, the

pneumatic ram will propel the headform toward the air bag at up to 11

km/h (7 mph). The test headform consists simply of a 165mm (6.5 inch)

outside diameter hemispherical shell. This headform is not instrumented

nor is it intended to impact with the interior of the vehicle.

Therefore, the agency is not specifying that it have a particular mass

in an effort to provide maximum flexibility in configuring a test

apparatus.

The automatic suppression plane of the vehicle, the point at which

the air bag suppression feature must be activated when the plane is

crossed by the headform, is located at that point rearward of the air

bag and forwardmost

[[Page 49975]]

of the center of gravity of the head of a seated occupant which the

manufacturer determines to be that point where, if the air bag is

deployed, a 3-year-old child dummy would meet specified injury

criteria.

NHTSA notes that the test procedure it is proposing for air bag

suppression features that suppress the air bag when an occupant is out-

of-position is similar to one developed by GM. The agency is placing a

copy of the GM procedure in the docket.

The agency requests comments as to whether the proposed test

procedure would accommodate air bag suppression systems under

development. In particular, the agency requests comments as to whether

these suppression systems would ``recognize'' the test device.

Additional questions concerning this proposed test procedure are

included in a section titled ``Questions'' later in this notice.

Static tests involving deployment of the air bag in the presence of

out-of-position 3-year old child dummies. If the low risk deployment

option were selected, a vehicle would be required to meet specified

injury criteria when the passenger air bag is deployed in the presence

of out-of-position 3-year-old child dummies. Because this test is

relatively difficult to run (it requires deployment of an air bag), the

agency is proposing that it be conducted at two positions which tend to

be ``worst case'' positions in terms of injury risk. The agency is also

proposing more detailed positioning procedures for these two tests than

for many of those proposed for the static suppression tests, since

injury measures may vary considerably with position. The agency is

proposing injury criteria appropriate for a 3-year-old child.

In the case of air bags with multiple inflation levels, the injury

criteria would need to be met only for the levels that would be

deployed in lower severity crashes, e.g., crashes of 32 km/h (20 mph)

or below. The agency notes that while an infant in a rear facing child

seat would always be extremely close to the passenger air bag, this is

not true for older children. An older child would most likely be

extremely close to the air bag in lower severity crashes, following

pre-crash braking. Of the 46 older children NHTSA has confirmed as

having been killed by a passenger air bag, 38, or 83 percent, were in

crashes with a delta V of 24 km/h (15 mph) or below, and all were in

crashes with a delta V of 32 km/h (20 mph) or below.

NHTSA requests comments concerning the threshold below which air

bag deployment levels should be required to meet injury criteria and

above which the injury criteria would not apply. The agency also

requests comments concerning test procedures.

Full scale dynamic out-of-position test requirements, which include

pre-impact braking as part of the test procedure. Under this option, a

vehicle would be required to meet injury criteria in a rigid barrier

crash test that included pre-impact braking as part of the test

procedure, using an unrestrained 3-year-old child dummy.

Pre-crash braking would be simulated by a vehicle, initially

accelerated to the predetermined pretest speed, that is retarded by

application of a suitable pre-crash deceleration prior to contact with

the rigid barrier. The agency believes that a 24 km/h (15 mph) impact

speed with the rigid barrier would generate the crash pulse necessary

to evaluate occupant crash protection to the out-of-position occupant.

Further details on this alternative test procedure are set forth in the

proposed regulatory text (see proposed S29 and S30 for Standard No.

208).

The agency is requesting comments on what impact speed should be

specified, as well as on other aspects of the test procedure for this

requirement, including dummy seating procedures. Depending on the

comments, the agency may modify the test speeds, dummy seating

procedures, or other aspects of the test procedure for the final rule.

c. Safety of 6-year-old children. These test requirements would

include the same basic tests and options as specified for 3-year old

child dummies, except that 6-year-old child dummies would be used in

place of 3-year old child dummies. The agency believes it is necessary

to specify requirements for 6-year-old child dummies as well as 3-year-

old child dummies because a device that worked for one might not work

for the other. For example, an automatic suppression feature that

suppressed air bag deployment in the presence of a 3-year-old child

dummy, based on information about size and/or weight, might not

suppress air bag deployment in the presence of the larger, heavier 6-

year-old child dummy.

The agency notes that, with respect to requirements for an air bag

suppression feature (weight or size sensor) that suppresses the air bag

when a child is present, some of the positions specified for the 3-

year-old child dummy would not apply to the 6-year-old child dummy.

This is because the 6-year-old child dummy is too large to be placed in

those positions.

NHTSA is proposing to specify use of the Hybrid III 6-year-old

child dummy. The Society of Automotive Engineers has guided the

development of this dummy, and recently completed that work. Therefore,

the motor vehicle industry is familiar with this dummy. The agency

published an NPRM in the Federal Register (63 FR 35171) to add the

Hybrid III 6-year-old child dummy to Part 572 on June 29, 1998.

d. Safety of small teenage and adult drivers. Out-of-position

drivers are at risk from air bags if they are extremely close to the

air bag at time of deployment. While any driver could potentially

become out of position, small statured drivers are more likely to

become out of position because they sit closer to the steering wheel

than larger drivers.

In order to address the risks air bags pose to out-of-position

drivers, NHTSA is proposing requirements using 5th percentile adult

female dummies. The agency is proposing three alternative test

requirements, the selection of which would be at the option of the

manufacturer.

The manufacturer options are similar to those using 3-year-old and

6-year-old child dummies, with one significant exception. Since air

bags provide safety benefits to small statured female drivers, it is

obviously not appropriate to permit manufacturers to suppress air bag

deployment under all conditions in the presence of such occupants.

Therefore, this type of suppression feature would not be permitted for

5th percentile adult female dummies.

The three manufacturer options being proposed by the agency are:

(1) test requirements for an air bag suppression feature that

suppresses the driver air bag when the driver is out of position, (2)

test requirements for low risk deployment involving deployment of the

air bag in the presence of out-of-position 5th percentile adult female

dummies, and (3) full scale dynamic out-of-position test requirements,

which include pre-impact braking as part of the test procedure.

Again, the manufacturer options which the agency is proposing

largely mirror the similar ones being proposed for 3-year-old and 6-

year old child dummies. The test procedures are adjusted to reflect the

driver, rather than the right front passenger position, and the

different dummy. The proposed injury criteria are the same as being

proposed for other tests using the 5th percentile adult female dummy.

The agency also notes that the option specifying test requirements

for an air bag suppression feature that suppresses the driver air bag

when an occupant is out of position would include both static tests and

tests using a moving test device. The static tests are needed to,

[[Page 49976]]

among other things, ensure that the driver air bag is not

inappropriately deactivated because the driver's arms are near the air

bag. Further details on this alternative test procedure are set forth

in the proposed regulatory text (see proposed S25.2, S27 and S28 for

Standard No. 208).

The agency also notes that the proposed full scale dynamic out-of-

position test requirements, which include pre-impact braking as part of

the test procedure, represent a surrogate for a variety of crash

situations where the driver might be essentially against the steering

wheel, in addition to directly addressing situations involving pre-

crash braking. These other situations include ones where small-statured

persons drive in a position where they are extremely close to the air

bag all of the time.

C. Injury Criteria

NHTSA is proposing injury criteria and performance limits that it

believes are appropriate for each size dummy. The agency is placing in

the public docket a technical paper which explains the basis for each

of the proposed injury criteria, and for the proposed performance

limits. The title of the paper is ``Development of Improved Injury

Criteria for the Assessment of Advanced Automotive Restraint Systems.''

Standard No. 208 currently specifies five injury criteria for the

Hybrid III 50th percentile adult male dummy in barrier crash tests: (1)

dummy containment--all portions of the dummy must be contained in the

vehicle passenger compartment throughout the test, (2) HIC (Head Injury

Criterion) must not exceed 1,000, (3) chest acceleration must not

exceed 60 g's, (4) chest deflection must not exceed 76 mm (3 inches),

and (5) upper leg forces must not exceed 2250 pounds.

Under today's proposal, NHTSA would generally apply these and

certain additional injury criteria to all of the dummies covered by the

proposal. However, the criteria would be adjusted to maintain

consistency with respect to the injury risks faced by different size

occupants. Also, with respect to some types of injuries, the agency is

considering alternative injury criteria.

For chest injury, NHTSA is considering two alternatives. Under the

first, or primary, alternative, the agency would add a new criterion,

Combined Thoracic Index (CTI), which was recently developed by the

agency. New analyses of cadaver test data using a variety of restraint

system combinations indicate that thoracic injury prediction can be

improved by considering a linear combination of chest deflection and

chest acceleration rather than solely by considering the criteria

independently. CTI links the combined effect of both parameters with

the risk of injury.

In proposing to add CTI, the agency has considered whether to

adjust the existing limits on chest deflection and/or chest

acceleration. In the absence of the existing injury criteria, the

proposed CTI limit (CTI = 1) would permit (for the Hybrid III 50th

percentile adult male dummy) chest deflection to exceed 76 mm (3

inches) when acceleration is very low, and acceleration to exceed 60

g's when chest deflection is very low.

NHTSA notes that, in the case of chest deflection, the current 76

mm (3 inch) limit is very close to the limit capable of being measured

by the Hybrid III 50th percentile adult male dummy. Therefore, it does

not appear to be possible to adjust this parameter in a meaningful way.

In the case of chest acceleration, the agency notes that it does not

have any cadaver data concerning injury risk associated with very low

deflection and chest acceleration above 60 g's. The agency requests

comments on this issue. NHTSA is especially interested in data and/or

analyses concerning the risk of injury associated with low deflection

and high acceleration.

As the second alternative for chest injury, the agency would simply

continue to maintain separate limits on chest acceleration and chest

deflection.

NHTSA is also proposing to add neck injury criteria. The agency

notes that it added neck injury criteria as part of the temporary sled

test alternative, although the standard does not otherwise specify neck

injury criteria. The neck injury criteria for the sled test alternative

include separate limits on flexion, extension, tension, compression and

shear.

NHTSA has recently developed an improved neck injury criterion,

called Nij. The agency believes that a disadvantage associated with

specifying separate limits for flexion, extension, tension,

compression, and shear is that it does not account for the

superposition of loads and moments, and the additive effects on injury

risk. The agency developed Nij to take account of these effects.

NHTSA is considering two alternatives with respect to neck injury

criteria. Under the first, or primary alternative, the agency would add

Nij to Standard No. 208. In terms of performance limits, the agency is

requesting comments on Nij=1.4 and on Nij=1. As discussed in the

technical paper concerning injury criteria, Nij=1 reflects certain

critical values developed using biomechanical data. However, based on

concerns about practicability, particularly with respect to tests

specifying use of the 5th percentile adult female dummy, as well as

concerns about correlations between biomechanical data and real-world

crash data, the agency believes that Nij=1.4 might be a more

appropriate performance limit. NHTSA requests comments on this issue.

As an alternative to Nij, NHTSA is also requesting comments on

establishing separate limits on flexion, extension, tension,

compression and shear, i.e., the approach adopted for the sled test

alternative. The proposed regulatory text includes this second

alternative as well as Nij.

As indicated earlier in this section, NHTSA is generally proposing

to apply the same injury criteria to all of the dummies covered by

today's proposal, adjusted to maintain consistency with respect to the

injury risks faced by different size occupants. There are, however,

some exceptions to this. The agency is not proposing to apply the dummy

containment injury criterion to the 12 month old CRABI dummy since that

criterion does not appear to be relevant to the low risk deployment

test using that dummy. The agency is not proposing chest deflection or

CTI requirements for the 12 month old CRABI dummy because that dummy

does not measure chest deflection. (As indicated above, chest

deflection is needed to calculate CTI.)

The agency requests comments on the proposed injury criteria, on

how they are calculated, and on the proposed performance limits. To

help facilitate focused comments, the agency is including specific

values for each performance limit in the proposed regulatory text.

However, NHTSA is considering a range of limits above and below each

specified value. Depending on the public comments, the agency may adopt

for the final rule values higher or lower than the ones included in the

proposed regulatory text. The agency requests commenters to address

what values should be selected for the final rule, their rationale for

their recommendation, and the implications of adopting lower or higher

values than those specified in the proposed regulatory text.

D. Dummy Recognition

The agency has explained many times that, in developing crash test

dummies for regulatory and research purposes, it seeks to ensure

insofar as possible that the measurements obtained on the dummy for

measuring injury risk are the same as would be obtained on a human

[[Page 49977]]

being. In other words, the dummy is used as a surrogate for determining

how a human being would fare in a particular crash situation.

As the agency proposes to specify the use of dummies and an out-of-

position occupant simulator to test suppression devices, it is

similarly necessary to ensure that the test results using these devices

will be as close as possible to those that would occur when a human

being is present. NHTSA notes, however, that test dummy compatibility

with air bag occupant presence and range sensors is not possible in all

cases using the currently available dummies. Some technologies, e.g.,

ultrasonic and active infrared, can be used to recognize human beings

but may not recognize current dummies or the out-of-position occupant

simulator.

NHTSA notes that it is monitoring research, funded by General

Motors, by the Johns Hopkins University Applied Physics Laboratory that

specifically investigates and addresses this subject. The project

objectives compare the characteristic output signals generated by both

human subjects and test dummies, in response to current and projected

air bag sensors of the following general types: ultrasonic/acoustic,

active infrared, passive infrared, capacitive, and electric field.

However, this is a longer-range research project, and is not expected

to be completed by the time of the final rule.

Specialized dummy treatments may be required to enable the test

dummy and out-of-position occupant simulator to properly interface with

the full range of projected sensor technologies. However, it is

possible that relatively straightforward surface treatments or clothing

selection may suffice for compatibility with ultrasonic and active

infrared sensor types.

The agency requests comments on this issue.

E. Lead Time and Proposed Effective Date

NHTSA has sought information by a variety of means to help it

determine when the vehicle manufacturers can provide advanced air bag

systems to consumers. This is known as lead time. Vehicle lead time is

a complex issue, especially when it involves technology and designs

that are still under development.

In three different formal actions, the agency has gathered

information concerning lead time. First, the agency held a public

meeting on advanced air bags on February 11 and 12, 1997, in Washington

D.C. The proceedings of that meeting are included in Docket NHTSA-97-

2814. Next, and as discussed earlier in this notice, JPL conducted, at

NHTSA's request, a survey of the automotive industry and independent

analysis concerning the readiness of the advanced air bag technologies.

Finally, the agency contracted Management Engineering Associates (MEA),

an engineering management consulting company, to conduct a feasibility

study on advanced air bag technologies.

These three sources of information indicated the same basic time

schedules: currently available technological solutions such as seat

sensors, seat belt buckle sensors, dual-stage inflators and advanced

air bag fold patterns, can be and will be in production between model

year 1999 and model year 2002. More sophisticated systems such as

dynamic occupant position sensing systems and pre-crash sensors, will

be available after September 1, 2001.

NHTSA has also held numerous meetings with the vehicle

manufacturers and suppliers during the past two years. The companies

have shared confidential information with the agency about their

ongoing development efforts and future product plans.

The agency notes that lead time for technology still under

development typically depends on two things: initial development to

demonstrate that a concept is feasible, and then further development to

apply the technology to a specific vehicle design. These typically

involve efforts both by suppliers and by vehicle manufacturers. In this

field of technology, it appears that much of the innovative development

is being borne by the component suppliers, based on performance

specifications defined by the vehicle manufacturers. First the systems

are designed, tested and produced in limited quantities by the

component manufacturers. Next these systems are turned over to the

vehicle manufacturers. The vehicle manufacturers then conduct prototype

design verifications, conduct production level equipment verification

and finally complete production and include the systems in their new

vehicles. MEA estimates the vehicle manufacturers' cycle could take an

average of 36 months.

The suppliers and vehicle manufacturers have, however, been working

on various advanced technologies for several years. Thus, to a large

degree, lead time is dependent on where the suppliers and vehicle

manufacturers are currently in their development and implementation

efforts. As discussed earlier in this notice, NHTSA believes that

different suppliers and vehicle manufacturers are at different stages

with respect to designing advanced air bags, and also face different

constraints and challenges, e.g., different states-of-the-art of their

current air bag systems, engineering resources, number of vehicles for

which air bags need to be redesigned, etc. NHTSA believes that these

differing situations can best be accommodated by phasing in

requirements for advanced air bags.

Taking account of all available information, including but not

limited to the wide variety of available technologies that can be used

to improve air bags (and thereby meet the proposed requirements) and

information concerning where the different suppliers and vehicle

manufacturers are in developing and implementing available

technologies, the agency is proposing to phase in the new requirements

in accordance with the following implementation schedule:

25 percent of each manufacturer's light vehicles manufactured

during the production year beginning September 1, 2002;

40 percent of each manufacturer's light vehicles manufactured

during the production year beginning September 1, 2003;

70 percent of each manufacturer's light vehicles manufactured

during the production year beginning September 1, 2004;

All vehicles manufactured on or after September 1, 2005.

The agency is proposing a separate alternative to address the

special problems faced by limited line manufacturers in complying with

phase-ins. The agency notes that a phase-in generally permits vehicle

manufacturers flexibility with respect to which vehicles they choose to

initially redesign to comply with new requirements. However, if a

manufacturer produces a very limited number of lines, e.g., one or two,

a phase-in would not provide such flexibility.

NHTSA is accordingly proposing to permit manufacturers which

produce two or fewer carlines the option of omitting the first year of

the phase-in if they achieve full compliance effective September 1,

2003. The agency is proposing to limit this alternative to

manufacturers which produce two or fewer carlines in light of the

statutory requirement concerning when the phase-in is to begin. Without

such a limitation, it would technically be possible for the industry as

a whole to delay introducing any advanced air bags for a year. However,

the agency doubts

[[Page 49978]]

that any full-line vehicle manufacturers would want to take advantage

of the alternative, given the need to achieve full compliance by

September 1, 2003.

As with previous phase-ins, the agency is proposing to exclude

vehicles manufactured in two or more stages and altered vehicles from

the phase-in requirements. These vehicles would be subject to the

advanced air bag requirements effective September 1, 2005. They would,

of course, be subject to Standard No. 208's existing requirements

before and throughout the phase-in.

Also as with previous phase-ins, NHTSA is proposing reporting

requirements to accompany the phase-in. The agency is proposing to

include the reporting requirements in 49 CFR Part 585, which currently

specifies automatic restraint phase-in reporting requirements. Since

the phase-ins currently addressed by Part 585 are complete, effective

September 1, 1998, the agency is proposing to replace the existing

language with regulatory text addressing the phase-in of Standard No.

208's requirements for advanced air bags.

NHTSA believes that the proposed phase-in addresses two potential

concerns. First, the agency believes that it would not be possible for

manufacturers which produce large numbers of models of passenger cars

and lights trucks to simultaneously design and implement advanced air

bags in all of their vehicles at once. All manufacturers have limited

engineering resources, and the same resources are often used for

different models. The proposed phase-in will address this concern.

Second, NHTSA wishes to see advanced air bags implemented

expeditiously, but wants to encourage the vehicle manufacturers to

adopt the best designs possible. The agency believes the proposed

phase-in balances these competing concerns.

The new air bag designs having the potential to offer the greatest

safety benefits, e.g. designs that would tailor inflation based on the

widest variety of relevant information including dynamic occupant

proximity, also have the longest lead times. If an effective date were

too early, it might force manufacturers working on such advanced

designs to drop those plans and adopt designs with shorter lead times.

At the same time, the agency recognizes that relatively simple

solutions, with shorter lead times, can be used to solve current

problems with air bags. The agency therefore does not want endless

quests for the ``perfect'' air bag to unnecessarily delay solving the

current problems.

An issue which is closely related to lead time for advanced air

bags is the time when amendments providing temporary reductions in

Standard No. 208's performance requirements should expire. The

amendment permitting manufacturers to provide manual on-off switches

for air bags in vehicles without rear seats or with rear seats too

small to accommodate a rear facing infant seat is scheduled to expire

on September 1, 2000. The amendment providing a generic sled test

alternative to Standard No. 208's unbelted barrier test requirements

originally had an expiration date of September 1, 2001, although, as

discussed earlier in this notice, this date has been superseded by the

NHTSA Reauthorization Act of 1998.

The agency received petitions objecting to the expiration dates for

these temporary amendments. In an appendix to this notice, NHTSA is

denying the petition concerning on-off switches to the extent that it

requests making the switch amendment permanent. However, the agency is

granting it to the extent that it is proposing phase out the switch

amendment as the upgraded requirements are phased in. The petitions

concerning the sled test option were mooted by the NHTSA

Reauthorization Act. As in the case of the switch amendment, the agency

is proposing to phase out the sled test option as the new requirements

are phased in.

During the proposed phase-in, the temporary amendments (sled test

alternative and OEM manual on-off switches for certain vehicles) would

not be available for vehicles certified to the upgraded requirements,

but would be available for other vehicles under the same conditions as

they are currently available. Thus, as manufacturers developed advanced

air bags, they would need to ensure that vehicles equipped with these

devices meet all of Standard No. 208's longstanding performance

requirements as well as the new ones being proposed today.

F. Selection of Options

NHTSA notes that, where a safety standard provides manufacturers

more than one compliance option, the agency needs to know which option

has been selected in order to conduct a compliance test. Moreover,

based on previous experience with enforcing standards that include

compliance options, the agency is aware that a manufacturer confronted

with an apparent noncompliance for the option it has selected (based on

a compliance test) may respond by arguing that its vehicles comply with

a different option for which the agency has not conducted a compliance

test. This response creates obvious difficulties for the agency in

managing its available resources for carrying out its enforcement

responsibilities, e.g., the possible need to conduct multiple

compliance tests (possibly involving full-scale vehicle crash tests)

for first one compliance option, then another, to determine whether

there is a noncompliance.

To address this problem, the agency is proposing to require that

where manufacturer options are specified, the manufacturer must select

the option by the time it certifies the vehicle and may not thereafter

select a different option for the vehicle. This will mean that failure

to comply with the selected option will constitute a noncompliance with

the standard regardless of whether a vehicle complies with another

option.

Similarly, for manufacturers which select the option for an

automatic suppression feature that suppresses the air bag when an

occupant is out of position, the agency is proposing to require that

the manufacturer must select the passenger side automatic suppression

plane and the driver side automatic suppression plane by the time it

certifies the vehicle, and may not thereafter select different planes.

This is to avoid situations where the agency conducts compliance tests

using the automatic suppression planes selected by the manufacturer and

is later told, after a test indicates an apparent noncompliance, that

the vehicle may comply for different automatic suppression planes.

G. Availability of Retrofit Manual On-Off Switches

As discussed earlier in this notice, on November 11, 1997, NHTSA

published in the Federal Register (62 FR 62406) a final rule exempting,

under certain conditions, motor vehicle dealers and repair businesses

from the ``make inoperative'' prohibition in 49 U.S.C. Sec. 30122 by

allowing them to install retrofit manual on-off switches for air bags

in vehicles owned by people whose request for a switch is approved by

NHTSA. The final rule is set forth as Part 595, Retrofit On-Off

Switches for Air Bags.

The purpose of the exemption is to preserve the benefits of air

bags while reducing the risk of serious or fatal injury that current

air bags pose to identifiable groups of people. In issuing that final

rule, NHTSA explained that although vehicle manufacturers are beginning

to replace current air bags

[[Page 49979]]

with new air bags having some advanced attributes, i.e., attributes

that will automatically minimize or avoid the risks created by current

air bags, an interim solution is needed now for those groups of people

at risk from current air bags in existing vehicles.

Just as NHTSA is proposing to phase out the temporary amendments to

Standard No. 208 as the upgraded requirements are phased in, the agency

is also proposing to phase out the availability of this exemption.

Under the proposal, retrofit on-off switches would not be available for

vehicles which have been certified to the advanced air bag requirements

being proposed in today's notice.

NHTSA requests comments, however, on whether retrofit on-off

switches should continue to be available under eligibility criteria

revised to be appropriately reflective of the capabilities of advanced

air bag technology. The agency observes that if such switches were to

be available at all, the criteria would need to be much narrower since

the risks would be smaller than they are currently. For example, the

passenger side air bag in a vehicle with a weight sensor would not

deploy at all in the presence of young children. Therefore, there would

no safety reason to permit a retrofit passenger side on-off switch

because of a need for a young child to ride in the front seat. The

agency requests any commenters who advocate any continued availability

of retrofit on-off switches to discuss how the existing eligibility

criteria should be tailored to the specific technologies that would be

used in vehicles certified to the advanced air bag requirements being

proposed in today's notice.

H. Warning Labels

As indicated in an earlier section of this notice, on November 27,

1996, the agency published in the Federal Register (61 FR 60206) a

final rule which, among other things, amended Standard No. 208 to

require improved labeling on new vehicles to better ensure that drivers

and other occupants are aware of the dangers posed by passenger air

bags to children. These warning label requirements did not apply to

vehicles with passenger air bags meeting specified criteria. The agency

is similarly proposing that vehicles certified to the advanced air bag

requirements being proposed today would not be subject to those warning

label requirements. The agency requests comments, however, concerning

whether any of the existing labeling requirements should be retained

for vehicles with advanced air bags and/or whether any other labeling

requirements should be applied to these vehicles.

I. Questions

As discussed earlier in this notice, NHTSA has sought to develop

requirements that are as performance-oriented as possible, and to

include options for manufacturers that account for the kinds of

technologies and designs that may be used. It is the agency's intent to

permit the vehicle manufacturers to use any technology or design which

can solve the problem of adverse effects of air bags to out-of-position

occupants, so long as all of the standard's performance requirements

can be met.

To aid the agency in obtaining useful comments, NHTSA is setting

forth in this section a specific list of questions for commenters

relating to a number of issues including, among other things: (1)

whether the agency's overall proposal, and whether each of the proposed

manufacturer options, would achieve an appropriate level of safety, and

(2) whether additional manufacturer options or test procedures are

needed to accommodate some technologies or designs. NHTSA notes that

the vehicle manufacturers and air bag suppliers are in the best

position to evaluate whether the proposed manufacturer options and test

procedures are appropriate for the technologies and designs they have

under development. Depending on the comments, the agency may issue a

final rule providing some but not all of the proposed options, and/or

provide additional manufacturer options or test procedures to

accommodate some technologies or designs.

For easy reference, the questions are numbered consecutively. NHTSA

encourages commenters to provide specific responses to each question

for which they may have information or views. In addition, in order to

facilitate tabulating the comments by issue, the agency encourages

commenters to respond to the questions in sequence, and to identify the

number of each question to which they are responding.

NHTSA requests that commenters provide as specific and documented a

rationale as possible, including an analysis of safety consequences,

for any positions that are taken. Commenters with a technical

background are encouraged to provide scientific analysis of these

matters.

The list of questions does not purport to be an all inclusive list

of items or information which the public may have available and believe

is valuable in assessing the issues. Commenters are encouraged to

provide any other data that they believe are relevant.

1. Overall safety. Does the agency's overall proposal achieve an

appropriate level of safety with respect to risks from air bags for

out-of-position occupants?

a. Please address this question separately for the driver side and

for the passenger side.

b. If a commenter believes that the proposal does not ensure an

appropriate level of safety, please provide a detailed explanation of

why. Please also describe in detail what additional or alternative

requirements the agency should consider, and the kind of technologies,

designs and lead time that would be needed to meet those requirements.

2. Adequacy of each proposed manufacturer option. Does each

proposed manufacturer option ensure an appropriate level of safety with

respect to the specific problem it addresses? How do the different

options differ with respect to benefits and costs? If a commenter

believes that a particular option should be changed or deleted for the

final rule, please explain why. Also, please explain the consequences

of changing or deleting the option, e.g., would greater lead time be

needed to meet one of the remaining options?

3. Accommodation of all effective designs. Do the proposed

manufacturer options accommodate all designs under development that

would effectively address air bag-induced injuries and/or fatalities,

and designs that are expected to be under development in the

foreseeable future? More specifically, is there a need to either modify

or add test procedures to the proposed options to accommodate

particular technologies or designs, or to add additional options? If a

commenter believes there is such a need, please provide a detailed

explanation of why, both with respect to why the technology is not

accommodated by the proposed options and why the technology will ensure

an appropriate level of safety. Please also provide a detailed

recommendation concerning what specific regulatory text the agency

should adopt to accommodate the technology.

4. Possible unintended consequences. To what extent could the

advanced technologies the manufacturers might adopt result in

unintended adverse consequences? For example, could some occupants face

higher risks than now? How should the agency consider that possibility

in this rulemaking? Are there any additional or alternative

requirements the agency should adopt to prevent such consequences?

5. Likely manufacturer responses. How would vehicle manufacturers

likely respond to the proposed requirements, i.e., what technologies

and design changes would they actually

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adopt? (Vehicle manufacturers are asked to provide a specific response

to this question, with respect to their future product plans.)

6. Necessity of all proposed manufacturer options. Are any of the

proposed manufacturer options unnecessary because no manufacturer would

ever select the option?

7. Proposed test procedures--in general. NHTSA notes that some of

the proposed test procedures are new. The agency requests specific

comments on each of the proposed test procedures, including whether any

of them should be made more specific and whether any additional

conditions should be specified.

8. Proposed injury criteria. As discussed earlier in this notice,

NHTSA is placing a technical paper in the docket which discusses the

proposed injury criteria. The agency requests comments on each of the

proposed injury criteria, the proposed calculation methods, and the

proposed performance limits. The agency also requests comments on

alternatives to the proposed criteria. Among other things, NHTSA

requests commenters to address what risk levels are acceptable, what

factors should be considered in selecting performance limits for

different test requirements, and whether the same limits should be

established for all test requirements, e.g., out-of-position tests, low

speed tests, high speed tests. The agency also requests commenters to

address how it should take account of uncertainties relating to the

injury criteria, especially with respect to children.

9. Dummy recognition. a. How should the agency address the

suitability of test dummies and out-of-position occupant simulators

(e.g., headforms) for testing technologies (e.g., weight sensors) for

detecting the presence of occupants and technologies (e.g., infrared

and ultra sound) for sensing the distance of occupants from an air bag?

To what extent can the addition of simple surface treatments or

clothing selection be used to solve this problem?

b. If full resolution of this or any other potential test procedure

problems should necessitate the performance of longer range (multi-

year) research, what interim approaches should the agency use for

assessing performance? For example, one possible approach would be to

permit vehicle manufacturers to specify the attributes of their

suppression devices, e.g., the size of the suppression zone and to

require out-of-position-type test requirements to be met for those

conditions. If, for example, a manufacturer specified that the

suppression zone for a vehicle's passenger-side air bag extended five

inches from the centerpoint of the air bag cover, injury criteria

performance limits would need to be met for infant and child dummies

located anywhere outside that zone. Under such an interim approach, the

introduction of effective suppression devices would not be delayed by

potential problems related to completing the development of test

procedures. While such an approach would not test the performance of

the suppression device itself, vehicle manufacturers would have strong

incentives, e.g., product liability considerations, to design the

device so that it works properly under real world conditions. While the

agency is hopeful that any potential test problems can be resolved in a

timely manner before the final rule, it requests comments on adopting

this type of interim approach, and on other potential interim

approaches, should the need rise.

10. Seating procedure for 5th percentile adult female dummy. NHTSA

notes that the seating procedure for the 5th percentile adult female

dummy set forth in the proposed regulatory text is based on the

equipment and procedures in SAE J826, ``Devices for Use in Defining and

Measuring Vehicle Seating Accommodations.'' The seating procedure is

similar to that specified in Standard No. 208 for the Hybrid III 50th

percentile adult male dummy. However, the agency is proposing, with

respect to the SAE J826 equipment, certain adjustments in the lengths

of the lower leg and thigh (femur) segments to make it appropriate for

the 5th percentile adult female dummy. The agency is also aware that

the SAE Hybrid III 5th Percentile Dummy Seating Procedures Task Group

is developing specialized seating equipment to locate the 5th

percentile adult female dummy. This equipment was expected to become

available by mid-summer 1998, and the agency will place specifications

for the equipment in the docket. NHTSA recognizes that this new

equipment might be used as an alternative to that specified in the

proposed regulatory text. The agency seeks comments on this issue.

11. Rough road tests. Are the proposed requirements and test

procedures for the rough road tests appropriate? The agency is

especially interested in comments concerning proposed specifications

for road surface, speed, and distance of travel.

12. Telltales for automatic suppression. For vehicles which have

automatic suppression features, are there both pros and cons to

requiring telltale lights on the instrument panel to advise vehicle

occupants of the operational status of the air bag? Please address this

question separately for the driver position and the passenger position,

and for rear facing infant seats and older children. If the agency did

not require a telltale light, what procedure should it use in testing

for determining whether an air bag is activated or deactivated?

13. Proposed automatic suppression test. The agency observes that

the proposed automatic suppression test is new and may require further

refinement. NHTSA therefore requests comments on all aspects of the

proposed test procedure, including, but not limited to, the following

issues. Is the proposed 165mm (6.5 inch) outside diameter hemispheric

headform an appropriate simulator of an out-of-position occupant for

the purposes of assessing the performance of an air bag suppression

device? What other characteristics should the headform possess if the

proposed headform is not sufficient? Should the agency specify the

surface and other material of the headform? Will the hemispheric

headform be recognized as a vehicle occupant by each of the various

suppression systems under development? If not, are there changes in the

headform that would make it recognizable?

14. Proposed dynamic out-of-position test. NHTSA notes that the

proposed dynamic out-of-position test is newly developed. The agency

requests commenters to address the following issues.

(a) When the proposed dynamic out-of-position test procedure is

conducted for various vehicles, what are the likely trajectories of the

dummies? Does the procedure result in the dummy moving directly toward

a ``worst-case'' position in terms of potential air bag risk for each

vehicle? If not, should any changes be made in the test procedure,

e.g., changing initial dummy position? Please address this question

separately for the 3-year old child, 6-year old child, and 5th

percentile adult female dummies.

(b) The proposed seating procedures for the dummies specify the use

of low friction material between the dummies and the seat. The agency

has proposed to specify the use of certain readily available fabrics

that could be used for this purpose. Comments are requested on other

means of achieving a low friction condition, such as specifying a

coefficient of static or sliding friction and the conditions for which

the coefficients would apply. Specific values of a friction factor are

solicited, as appropriate.

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(c) Should the proposed dynamic out-of-position test be run at

different speeds or angles? NHTSA notes that if a 24 km/h (15 mph)

impact were specified, it is conceivable that manufacturers might be

able to certify to this requirement by raising their deployment

thresholds to, or slightly above, that level. The agency requests

comments on whether higher deployment thresholds alone could be used to

meet this test, and, if so, the safety implications of this type of

countermeasure.

(d) What are reasonable tolerances on final impact speed and

deceleration in order to ensure that a test is repeatable? Should a

specific methodology be adopted to ensure an appropriate degree of

repeatability?

15. Tests with child dummies. (a) NHTSA is proposing that tests

using infant dummies be conducted with any rear facing child restraint

which was manufactured for sale in the United States between two years

and ten years prior to the date the first vehicle of the model year

carline of which the vehicle is a part was first offered for sale to a

consumer. The agency is proposing the same approach, with respect to

forward-facing child seats and booster seats, for tests using older

child dummies. The agency requests comments on this approach. Is there

an effective alternative means of ensuring that vehicle manufacturers

take account of the variety of different child restraints in use as

they design their systems?

(b) NHTSA is proposing to specify use of the 12-month-old CRABI

dummy for tests using rear facing infant restraints. However, some rear

facing infant restraints may only be certified for use with smaller

infants, e.g., 9-month-olds. This raises the issue of whether the

proposed dummy could be placed into these child restraints. The agency

requests comments on how to address this issue.

(c) Some rear facing child seats are now produced for children

older than 12 months. Should the agency specify additional test

requirements to address this situation?

(d) Should the agency specify test requirements using car beds and,

if so, what specific requirements?

16. Older children. Standard No. 208 currently defines advanced air

bag to include, among other things, a passenger air bag that provides

an automatic means to ensure that the air bag does not deploy when a

child seat or child with a total mass of 30 kg (66 pounds) or less is

present on the front outboard passenger seat. That definition was

included because vehicles with such air bags are not required to have

certain warning labels.20 NHTSA notes that the part of the

definition referring to a child with a total mass of 30 kg (66 pounds)

or less was included to reflect the possible use of weight sensors. The

30 kg (66 pound) threshold was originally suggested by Mercedes-Benz

and corresponds to the weight of a 50th percentile 10-year-old and a

95th percentile 7-year-old. The agency stated that the threshold was

far enough below the weight of a 5th percentile adult female

(approximately 46 kg (101 pounds)) to avoid inadvertently deactivating

the air bag when a small adult is occupying the seat. In today's

proposal, the agency is not proposing a threshold as such but is

instead proposing tests using specified dummies. The heaviest child

dummy that would be used in testing a weight sensor intended to

suppress air bag deployment for children would be the Hybrid III 6-

year-old child dummy, which has a weight of approximately 24 kg (51.8

pounds). No Hybrid III child dummies are available that correspond a 9-

year-old or 10-year-old. A similar issue would exist with respect to a

sensor intended to suppress air bag deployment based on size, i.e., the

largest size child dummy tested would be the 6-year-old. The agency

requests comments on the potential gap between the size/weight of the

6-year-old child dummy and the largest/heaviest child for which

suppression might be appropriate (based on presence as opposed to being

out-of-position) and how the agency should deal with this issue. For

example, should the agency

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