Federal Motor Vehicle Safety Standards; Head Impact Protection

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571 and 572

[Docket No. 92-28; Notice 6]

RIN 2127-AG07

Federal Motor Vehicle Safety Standards; Head Impact Protection

AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.

ACTION: Advance Notice of Proposed Rulemaking.

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

SUMMARY: This document grants four petitions to commence rulemaking to

amend upper interior head protection requirements to accommodate

vehicles equipped with a dynamic head protection device which is

activated in a side impact (e.g., a side air bag). This document

requests information on various issues NHTSA must evaluate before

issuing a notice of proposed rulemaking for these petitions.

DATES: Comments must be received by April 22, 1996.

ADDRESSES: All comments must refer to the docket and notice number set

forth above and be submitted (preferably in 10 copies) to the Docket

Section, National Highway Traffic Safety Administration, Room 5109, 400

Seventh Street S.W., Washington, DC 20590.

FOR FURTHER INFORMATION CONTACT: The following persons at the National

Highway Traffic Safety Administration, 400 Seventh Street, S.W.,

Washington, D.C. 20590:

For non-legal issues:

Dr. William Fan, Office of Vehicle Safety Standards, NPS-14,

telephone (202) 366-4922, facsimile (202) 366-4329, electronic mail

``[email protected]''.

For legal issues:

Mary Versailles, Office of the Chief Counsel, NCC-20, telephone

(202) 366-2992, facsimile (202) 366-3820, electronic mail

``[email protected]''.

SUPPLEMENTARY INFORMATION: On August 18, 1995, NHTSA published a final

rule amending Standard No. 201, Occupant Protection in Interior Impact,

to require passenger cars, trucks, buses and multipurpose passenger

vehicles with a gross vehicle weight rating (GVWR) of less than 10,000

pounds to incorporate measures to prevent or reduce injury when a

vehicle occupant's head strikes upper interior components during a

crash. The covered components include pillars, side rails, headers, and

the roof. The amendments add procedures and performance requirements

for a new in-vehicle component test (60 FR 43031). The period for

submittal of petitions for reconsideration closed September 19, 1995.

NHTSA received nine petitions for reconsideration of the final

rule. Four of those petitions (BMW, Mercedes-Benz, Volkswagen, and

Volvo) asked for a variety of changes to the final rule if a vehicle is

equipped with a dynamic head protection countermeasure which is

activated in a crash (i.e., a side air bag, hereafter referred to as

dynamic systems). In addition, four manufacturers (BMW, Ford, Mercedes-

Benz, and Volvo) requested meetings with the agency to discuss the

impact of the final rule on dynamic systems. The petitions requested a

variety of changes to the rule, including:

A complete exclusion of any vehicle equipped with a

dynamic system,

An exclusion of targets protected by a dynamic system,

For targets protected by a dynamic system, a reduction of

the free motion headform (FMH) impact speed from 15 miles per hour

(mph) to 12 mph when tested without the dynamic system activated,

The inclusion of a dynamic test in the standard, and

Testing with the dynamic system activated.

Because these issues are outside the scope of the rulemaking that

led to the August 18 final rule, it is not a proper subject for a

petition for reconsideration. Therefore, the agency is treating the

Mercedes-Benz petition, and the related portions of the BMW, Volkswagen

and Volvo petitions as petitions for rulemaking, and is granting those

petitions. Before publishing a notice of proposed rulemaking, the

agency wishes to conduct some evaluations. To assist the agency in

conducting these evaluations, this notice requests comments on the

issues identified above.

[[Page 9137]]

Performance Evaluation

Currently, Standard No. 201 requires that a vehicle's instrument

panel meet the Standard when impacted at a relative velocity of 15

miles per hour, with one exception. The exception is for vehicles that

meet the occupant protection requirements of S5.1 of Standard No. 208,

``Occupant Crash Protection,'' by means of an inflatable restraint.

Those vehicles need only meet the performance requirement when impacted

at a relative velocity of 12 miles per hour.

The agency notes that while this exception appears to be similar to

one of the changes requested by the petitions, there is an important

distinction. The existing exception is premised upon the existence of a

dynamic performance test that provides an objective evaluation of the

protection provided by the inflatable restraint. That test provides

assurance that the inflatable restraint provides protection that is a

suitable substitute for the protection otherwise afforded by the

Standard. However, the exception sought by the petitioners is not

necessarily premised on the existence of such a test for evaluating the

performance of dynamic systems. NHTSA believes that before it considers

any changes in the requirements of the August 18 final rule, it should

have a method of testing dynamic systems for a minimum level of

performance. Since such a method does not now exist, one must be

developed. Either there must be a single testing method appropriate for

evaluating the performance of the wide range of dynamic systems under

development, or there must be a variety of test methods that, together,

are sufficient for testing all systems and ensuring that they provide

equivalent protection.

NHTSA is aware of two categories of dynamic systems that are under

consideration by the manufacturers. The first category is dynamically

deployed padding. The dynamically deployed padding would provide

improved protection for head impacts with the upper interior components

already covered by the final rule. However, the dynamically deployed

padding is anticipated to provide protection in higher severity impacts

than that provided by the static padding which would otherwise be

utilized to meet the requirements of the final rule. The second

category includes dynamically deployed air bags or other inflatable

devices such as BMW's Inflatable Tubular Structure. This technology

provides head protection for impacts with various vehicle upper

interior components. It also potentially affords protection for side

impacts with external objects such as trees and poles or the front high

hooded areas of a colliding vehicle.

Since the dynamic systems may have the potential to provide

improved head protection beyond that provided by the final rule, the

agency is considering rulemaking to allow them. However, as noted

above, the agency believes that test procedures must be developed to

evaluate the dynamic systems in order to assure that the protection

afforded by the dynamic systems is a suitable substitute for that

provided by the final rule.

A number of test procedures have been suggested. These include:

Procedures for Dynamically Deployed Padding

For targets protected by dynamically deployed padding, impact the

targets with the FMH at 12 mph, prior to the deployment of the padding.

The targets would be located using the existing procedures. Impact

these same target locations again, this time at 20 mph, after

deployment of the padding. The higher speed for testing the deployed

padding is intended to assure that increased head protection is

provided by the advanced technology. (For an explanation of the 20 mph

test speed, see the questions below regarding benefits.) Conduct crash

tests at 15-20 mph to ensure that sensors activate the deployment of

the advanced padding under those conditions.

Procedures for Dynamically Deployed Air Bags and Other Inflatable

Devices

(1) For targets protected by an air bag or other inflatable device,

conduct FMH impacts at 12 mph. The advanced systems are not deployed

for these tests. All other targets are tested at 15 mph.

(2) Conduct a side impact crash test of the vehicle into a 250 mm

diameter rigid pole at 30 kph. The vertical centerline of the pole is

aligned with the center of gravity of the dummy's head. The dummy's

seat is positioned forward of the mid-seating location such that the

dummy's head is sufficiently within the front window opening that the

striking pole will not contact the B-pillar.

(3) Conduct a side impact crash test at 50 kph using the ISO 10997

moving deformable barrier (MDB) fitted with a rigid face whose top edge

is not less than 1250 mm above the ground. The dummy's seat is

positioned forward of the mid-seating location such that the dummy's

head is sufficiently within the front window opening that the striking

MDB can make direct head contact. The second and third test procedures

for the ``dynamically deployed air bags and other inflatable devices''

were presented by the U.S. delegation to the ISO/TC 22/SC 10/WG 3 in

its draft technical report, Document N100, ``Road Vehicles--Test

Procedures of Evaluating Various Occupant Interactions with Deploying

Side Impact Air Bags.''

To assist the agency in developing possible ways of evaluating

performance, the agency requests answers to the following questions:

1. What test procedures could be used to measure the performance of

a dynamic system?

2. What performance criteria would assure that advanced systems,

when deployed, provide protection equivalent to that provided by

countermeasures that meet the requirements of the final rule?

3. Are there other test methods appropriate for dynamic systems

using full scale crash tests and an anthropomorphic test device?

4. If the agency were to propose a lower impact speed for targets

protected by a dynamic system, are there components of the dynamic

system which are not protected by the system but which could not meet

the upper interior requirements at the current impact speed (15 mph)?

Benefits

The majority of dynamic systems known to NHTSA would offer occupant

protection only in side impacts. The final rule was intended to provide

head impact protection in frontal, side, and rollover crashes. Before

deciding whether to propose amendments to accommodate vehicles with

dynamic systems, NHTSA wishes to explore the nature and extent of any

tradeoffs. To do this, it must compare the benefits provided by these

dynamic systems with the benefits afforded by the final rule. Excluding

targets or reducing the impact speed for targets would reduce the

benefits for those targets in crashes which do not cause the dynamic

system to deploy. Conversely, the dynamic systems may offer increased

benefits when they do deploy. To assist the agency in evaluating the

relative benefits of possible proposals, the agency requests answers to

the following questions:

5. What effect would reducing test speeds have on injuries in non-

deployment crashes?

6. What is the effectiveness of each dynamic system in reducing

fatalities and injuries? What percent reduction in the various injury

criteria (e.g., HIC) would result if these technologies were installed?

Would this reduction vary by delta-V? If so, specify the relationship

[[Page 9138]]

between delta-V and injury criteria reduction for the specific system.

7. Could the dynamic systems cause increases in neck injuries? If

so, what data are available to quantify this impact? What criteria can

be used to determine whether lateral neck motion is increasing or

causing injury?

8. Some advanced technologies appear to offer potential reductions

in the likelihood of ejection. What would the effectiveness of dynamic

systems be in reducing ejection in side or other impact modes or in a

subsequent collision?

9. The dynamic systems known to NHTSA will deploy and protect the

near-side occupant in a side impact. Will the dynamic system for the

far-side occupant deploy in a side impact or in rollovers to protect

against possible rebound effects or subsequent collision?

10. Do MY 1996 vehicles meet 12 mph test requirements? Do any MY

1996 vehicles meet 15 mph test requirements?

11. Should an impact speed higher than 15 mph be used in FMH

testing of the system in order to compensate for the loss in benefits

because the system does not deploy in rollover and frontal crashes? If

so, is 20 mph an appropriate impact speed?

12. Are there existing accident data analyses concerning head

injuries as a function of crash modes and target components?

Miscellaneous Questions

To allow NHTSA to become better acquainted with the dynamic systems

under development, the agency requests answers to the following

questions:

13. Are dynamic systems compatible with the B-pillar mounted

shoulder anchorage point? Are integrated restraint seats (IRS), which

have shoulder belt anchorages attached to the upper backseat, more

compatible with the dynamic systems?

14. How much would the dynamic systems add to the price and weight

of the vehicle?

15. What are the performance criteria for the sensor system

designs? What is the time interval necessary for full deployment of the

dynamic system?

16. If changes were made to the August 18 final rule, what is the

anticipated time frame for introduction of dynamic systems? Are any

dynamic systems being introduced prior to the requirements of the

August 18 final rule?

17. Will the systems be introduced as optional or standard

equipment?

Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

This rulemaking document was reviewed under E.O. 12866,

``Regulatory Planning and Review.'' Further, this action has been

determined to be ``significant'' under the Department of

Transportation's regulatory policies and procedures because of

anticipated public interest. Any anticipated rulemaking resulting from

this notice would provide manufacturers with an alternative to the

requirements in the August 18 final rule. A decision by a manufacturer

to avail itself of the alternative would entail use of technology

(i.e., dynamic systems) that may well be more costly than the padding

which could be used to comply with the final rule. The agency solicits

information from the manufacturers concerning those cost of those

dynamic systems.

Executive Order 12612 (Federalism)

NHTSA has analyzed this notice in accordance with the principles

and criteria contained in E.O. 12612, and has determined that it does

not have significant federalism implications to warrant the preparation

of a Federalism Assessment.

Submission of Comments

Interested persons are invited to submit comments. It is requested

but not required that 10 copies be submitted.

All comments must not exceed 15 pages in length. (49 CAR 553.21).

Necessary attachments may be appended to these submissions without

regard to the 15-page limit. This limitation is intended to encourage

commenters to detail their primary arguments in a concise fashion.

If a commenter wishes to submit certain information under a claim

of confidentiality, three copies of the complete submission, including

purportedly confidential business information, should be submitted to

the Chief Counsel, NHTSA, at the street address given above, and seven

copies from which the purportedly confidential information has been

deleted should be submitted to the Docket Section. A request for

confidentiality should be accompanied by a cover letter setting forth

the information specified in the agency's confidential business

information regulation. 49 CFR Part 512.

All comments received before the close of business on the comment

closing date indicated above will be considered, and will be available

for examination in the docket at the above address both before and

after that date. To the extent possible, comments filed after the

closing date will also be considered. Comments will be available for

inspection in the docket. The NHTSA will continue to file relevant

information as it becomes available in the docket after the closing

date, and it is recommended that interested persons continue to examine

the docket for new material.

Those persons desiring to be notified upon receipt of their

comments in the rules docket should enclose a self-addressed, stamped

postcard in the envelope with their comments. Upon receiving the

comments, the docket supervisor will return the postcard by mail.

(Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;

delegation of authority at 49 CFR 1.50)

Issued on March 1, 1996.

Barry Felrice,

Associate Administrator for Safety Performance Standards.

[FR Doc. 96-5292 Filed 3-6-96; 8:45 am]

BILLING CODE 4910-59-P