Federal Motor Vehicle Safety Standards; Steering Control Rearward Displacement

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[NHTSA Docket No. 98-4027, Notice 1]

RIN 2127-AG01

Federal Motor Vehicle Safety Standards; Steering Control Rearward

Displacement

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

ACTION: Termination of rulemaking.

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SUMMARY: This document terminates a rulemaking proceeding in which the

agency proposed to exclude from its standard on steering control

rearward displacement air bag-equipped passenger cars and other light

vehicles certified as complying with the agency's occupant crash

protection standard based upon the frontal barrier crash test. The

agency proposed this exclusion because the engineering need to provide

a stable air bag platform in order to perform consistently during an

unrestrained dynamic crash test would ensure that vehicle manufacturers

design their vehicles so that there would be little steering control

rearward displacement. That necessity would obviate the need for

manufacturers to conduct another crash test just to certify steering

control rearward displacement performance.

However, since the proposal, the agency has temporarily allowed the

manufacturers to certify their vehicles to the occupant protection

standard based upon an unrestrained sled test and a restrained (or

belted) barrier test. The capability of the steering column to provide

a stable platform for the air bag is not tested in a sled test since no

structural deformation of the structure occurs nor does the restrained

occupant 30 mph barrier test adequately evaluate the platform stability

since the belted dummy does not significantly load the steering

assembly. NHTSA anticipates that nearly all manufacturers will certify

to the unrestrained occupant protection standard based on the less

rigorous sled test procedure. Therefore, the agency is terminating this

rulemaking.

FOR FURTHER INFORMATION CONTACT:

On technical matters: Mr. John Lee, in the Office of

Crashworthiness Standards, telephone: 202-366-4924, facsimile: 202-493-

2739, e-mail: [email protected].

On legal matters: Mr. Paul Atelsek, in the Office of the Chief

Counsel, telephone: 202-366-2992, e-mail: [email protected].

The mailing address is: National Highway Traffic Safety

Administration, 400 Seventh Street, SW, Washington, DC, 20590.

SUPPLEMENTARY INFORMATION:

I. Background

Pursuant to the March 4, 1995 directive, ``Regulatory Reinvention

Initiative,'' from the President to the heads of departments and

agencies, NHTSA undertook a review of all its regulations and

directives. During the course of this review, the agency identified

several regulations as potential candidates for rescission or

amendment. One of these regulations was Standard No. 204, Steering

Control Rearward Displacement. The agency concluded at that time that

requiring compliance with the standard appeared to be redundant for

certain vehicles, given the actions which were separately required to

be taken to comply with Standard No. 208, Occupant Crash Protection.

Standard No. 204 specifies a dynamic crash test to measure the

rearward displacement of a vehicle's steering column to ensure that the

driver is not ``speared'' by the column. The standard specifies that

the upper end of the steering column and shaft may not be displaced

horizontally rearward more than 5 inches (127 mm) in a 30-mile-per-hour

frontal barrier crash test. The standard applies to passenger cars and

other light vehicles.

Passenger cars and light vehicles are also required to pass a

dynamic test specified in Standard No. 208, Occupant crash protection.

For unrestrained occupants, Standard No. 208 requires either a frontal

impact crash test into a rigid barrier at 30 mph or a dynamic sled

test, with the performance measured by the impact forces on an

anthropomorphic test dummy rather than by the displacement of a vehicle

component. Air bags became mandatory in all passenger cars on September

1, 1997, and will be required in all light vehicles by September 1,

1998. Since March 19, 1997, it has been permissible to certify vehicles

on the basis of a sled test instead of a crash test. The agency

believes that the great majority of auto manufacturers are now

certifying vehicles using the sled test.

On November 16, 1995, the agency published a Notice of Proposed

Rulemaking, (60 FR 57565) proposing that vehicles be excluded from

having to comply with Standard No. 204 if these vehicles were certified

to comply with the frontal barrier crash test requirements of Standard

No. 208 by means of an air bag. The basis for the proposal was that the

engineering considerations that govern designing a vehicle with air

bags would ensure that the vehicle would have the same performance for

steering control rearward displacement as is currently required by

Standard No. 204. One of the most fundamental engineering

considerations when designing an air bag equipped vehicle is to provide

a secure platform for the air bag. The designer must know the relative

location of the air bag and the protected occupant during a crash

because, if the air bag platform were moving up or down, or backward or

forward during a crash, it could adversely affect air bag performance.

Since the driver's air bag is located in the steering column, the

NPRM stated that the engineering measures necessary to provide a secure

air bag platform will also ensure that Standard No. 204's specified

performance for steering control rearward displacement is satisfied,

even if the standard were no longer applicable. In case the public knew

of some factors that NHTSA had not considered, NHTSA also asked for

comment on whether there was any possibility that the proposed Standard

No. 204 exclusion might result in an increase in injuries not protected

against by Standard No. 208. The NPRM stated that the proposed rule

would have minor, nonquantifiable cost savings. The public comment

period closed on January 16, 1997.

Subsequent to the issuance of the NPRM on Standard No. 204, on

March 19, 1997, in order to facilitate the

[[Page 38800]]

depowering of air bags, the agency temporarily amended Standard 208 to

permit vehicle manufacturers to certify their vehicles using a sled

test procedure, rather than a crash test. In the sled test, there is no

possibility of steering column movement due to deformation of the

vehicle structure from crash forces, regardless of how good or bad the

steering column design. Although the standard still permits

manufacturers to certify their vehicles using the frontal barrier crash

test using an unrestrained test dummy, as specified in S5.1, as noted

above, essentially all manufacturers are now using the sled test for

Standard No. 208 certification. The standard still requires a belted

barrier test. Currently, the agency is in the midst of developing an

NPRM on improved air bags that may reinstate some form of barrier test

requirement.

II. Summary of Public Comments

The agency received six comments on the proposal to exclude air bag

equipped vehicles from Standard No. 204. Advocates for Highway and Auto

Safety (Advocates) and Mr. Lee F. Graser (an automobile

reconstructionist) were generally opposed to the proposal. The

Insurance Institute for Highway Safety (IIHS), the American Automobile

Manufacturers Association (AAMA), and two auto manufacturers,

Volkswagen and Mitsubishi, supported the proposal. The following is a

brief summary of these comments.

As noted above, two commenters disagreed with excluding these

vehicles from Standard No. 204. Mr. Lee F. Graser, President of LAS-KDS

Inc. (an automobile reconstructionist) commented that the current

standard was ``incredibly successful in removing the ``spear-like''

qualities from the steering column.'' He based his comment on 30 years

of experience in rebuilding automobiles damaged in a crash, and

examining thousands of wrecked automobiles. He agreed that vehicles

will continue to meet the crash test standards at 30 miles per hour,

but said that in more severe (i.e., higher speed) crashes, the

exclusion from the requirement will remove an important safety margin

and result in the reintroduction of a hazard eliminated long ago.

Advocates was concerned that the exclusion would exacerbate a

danger that it believes exists even with Standard No. 204 in place. Its

main concern was the ``dangers due to the proximate positioning of the

drivers to the steering wheel air bag modules.'' It noted that short

women and many older drivers must sit further forward than other

drivers to comfortably reach the steering wheel. In such cases, it

stated, the distance from the air bag to the driver's chest would be

6.5 to 4.5 inches. Drivers seated in this zone could be injured by the

deploying air bag. Advocates' apparent concern with this exclusion is

that, without Standard No. 204, the steering column would move

rearward, even closer to the driver, prior to air bag deployment. If

this occurred, there would be a very forceful impact of the air bag on

the driver (air bag deployment force would be greater on a driver

closer to the housing).

Advocates also argued that there was no supporting data for the

exclusion and therefore the agency's proposed action could be

considered capricious. Advocates commented that NHTSA has no data to

support the presumption that manufacturers will continue to maintain

compliance with Standard No. 204 if this exclusion is provided.

Advocates also suggested that NHTSA needs test data showing that

vehicles that do not comply with Standard No. 204 could still ensure

safety of small passengers and not increase the risk of exacerbating

trauma from steering wheels.

Finally, Advocates noted the request for comment that NHTSA had

issued on air bag-related injuries (NHTSA Docket 74-14, Notice 97, 60

FR 65554, November 9, 1995). Advocates stated that it could not

understand why the agency would complicate the understanding of this

complex injury issue by adding another major variable (i.e., a presumed

increase in steering wheel movement).

Four commenters agreed with excluding air bag equipped vehicles

from Standard No. 204. Mitsubishi concurred without substantive

comment. Volkswagen concurred and commented that the exclusion would

save it testing costs of about $20,000 plus the cost of the vehicle for

each car line because an extra crash test was required by Standard No.

204. It stated that the savings might be as much as $700,000 on a new

car line, because a prototype vehicle would have to be used in the

testing.

Volkswagen also noted that a proposal to make a similar exclusion

from the ECE version of this standard is under discussion in Europe,

implying that NHTSA should adopt the proposal in the interest of

harmonization.

The AAMA supported the proposal. The AAMA confirmed that for an air

bag equipped vehicle, the steering column location must remain

relatively stable during a Standard No. 208 barrier test to

consistently meet the test requirements. It provided an analysis of

NHTSA's own Standard No. 204 ``indicant'' test reports for member

companies: GM, Ford and Chrysler. The AAMA stated that the NHTSA

indicant test data showed that the displacement was zero in most cases

and well below the 5.0 inch (12.7 cm) limit in all cases. The AAMA also

pointed out that, in a 1981 evaluation of the standard, the agency

found that steering wheel rearward displacement was highly correlated

to the vehicle's change in velocity during the crash (Delta V). ``An

Evaluation of Federal Motor Vehicle Safety Standards for Passenger Car

Steering Assemblies'', Standard No. 203--``Impact Protection for the

Driver'', Standard No. 204 ``Rearward Column Displacement,'' January

1981, NHTSA Technical Report DOT HS 805 705. The agency evaluation

indicated that, in crashes with a Delta V of less than 15 mph, there

was virtually no rearward displacement. The AAMA did not provide any

data from the motor vehicle manufacturers. It agreed that the proposal

should be effective 30 days after the final rule.

The IIHS supported the proposed exclusion from Standard No. 204,

stating that the current dynamic test in Standard No. 208 with an

unbelted dummy is more than sufficient to limit excessive rearward

steering wheel displacement in a centric crash specified by Standard

No. 204. However, it was concerned that Standard No. 204's centric flat

barrier crash test is inadequate, because steering control rearward

displacement continues to be a problem in offset crashes. To support

this offset crash concern, IIHS cited data from offset crash tests of

16 vehicles that showed rearward displacements of up to 6.7 inches (17

cm). It also provided a summary of an actual fatal offset crash which

it believes might not have been fatal if the column had not moved

rearward by 7.5 inches (19 cm). IIHS urged NHTSA to continue work on

offset testing, and explore rulemaking on the subject.

III. Discussion of Issues

A. Don't Change a Standard That Works

Mr. Graser stated that Standard No. 204 has resulted in significant

improvement in occupant protection by removing the spear-like qualities

of the steering column. Advocates stated that there was no basis for

the agency's presumption that motor vehicle manufacturers will maintain

compliance after exclusion from Standard No. 204.

The agency agrees with Mr. Graser that designs that conform to

Standard No. 204 mitigate chest injuries. The standard did accomplish

its purpose,

[[Page 38801]]

according to the agency's analysis. In the agency's regulatory

evaluation of the benefits of its steering column regulations (Standard

Nos. 204 and 203, Impact Protection for the Driver From the Steering

Control System), NHTSA estimated that the two steering column standards

in tandem were cost-effective and prevented 1,300 fatalities and 23,000

nonfatal injuries per year when all automobiles complied. (Note that

the agency has already excluded from Standard No. 203 vehicles that

comply with Standard No. 208 using air bags because it concluded that

requiring compliance with Standard No. 203 was redundant (40 FR 17992,

April 24, 1975)). Therefore, Standard No. 204 did prompt some useful

changes in steering column design.

The NPRM was based on the assumption that manufacturers would have

to conduct a dynamic crash test with unbelted dummies for Standard No.

208, an assumption that is no longer valid.

Vehicle manufacturers must design a stable air bag platform to

ensure good, repeatable performance for the air bag in a crash. In

other words, steering columns must be designed to ensure the air bag

mounted in the steering wheel hub will remain in a constant position

relative to the driver during a crash. However, Standard No. 208's

unbelted performance requirements would adequately control steering

column movement only during a full-barrier crash test. Conversely, the

sled test does not ensure that the steering column will be adequately

designed. Additionally, the belted occupant 30 mph barrier test, which

is still required, does not adequately evaluate the air bag platform

stability since the belted dummy does not significantly load the

steering assembly.

B. Risk of Air Bag Injury to Small Occupants

In response to Advocates' concern about negative safety impacts on

smaller occupants, the agency notes that rearward displacement of the

steering column may not contribute to close proximity air bag

deployments because displacement and deployment may occur at different

times during a crash. To illustrate, in a standard barrier test the air

bag begins to deploy between 15 to 20 milliseconds after impact and is

completely deployed by 50 to 60 milliseconds after impact. In these

crash tests, steering column dynamic rearward displacement and steering

column collapse almost always occur after completion of air bag

deployment, starting at about 60 milliseconds. During a Standard No.

208 unbelted full barrier impact compliance test, this steering column-

occupant interaction is measured by the Hybrid III dummy. Therefore,

excessive rearward displacement of the steering column in unbelted full

barrier-type impacts would likely impact the dummy and cause a failure

of the Standard No. 208 test. However, due to the wide variety of crash

types in the real-world, the agency can see the potential for

situations where steering column movement and air bag deployment could

occur at the same time.

C. Supporting Data

In response to Advocates' complaint that NHTSA has no data to

justify this proposed exclusion, NHTSA based its NPRM on an engineering

analysis of the steering column design requirements implied or

necessitated by the then-existing Standard No. 208 full-barrier impact

requirements.

Moreover, it would have been impossible to generate the test data

on non-compliant vehicles that Advocates says is necessary. Evidence

indicates that all vehicle designs comply with Standard No. 204, so

there are no non-complying vehicles to test. NHTSA reviewed the results

of Standard No. 204 compliance tests before publishing the NPRM. The

results of that review are in the docket. In that review, the agency

found that in the last 28 years, there have been three cases worthy of

further investigation, but no actual non-compliances. No air bag-

equipped vehicle has failed this test.

The agency reviewed its 1996 calendar year information requests to

vehicle manufacturers, which resulted in the submission of 36 reports

of Standard No. 204 compliance tests. This 1996 sample includes 25

passenger cars and 11 light trucks. A summary of the steering column

rearward displacement data from these manufacturer reports has been

placed in the docket. The average value of the maximum dynamic

horizontal deflection was 42 millimeters (1.6 inches). The range of

horizontal deflections ranged from 0 mm (0 in.) to 99 mm (3.9 in.).

However, history may not be a guide when the assumptions are

changed. NHTSA agrees with Advocates that there is no evidence that

sled-tested and belted-barrier-tested vehicles will continue to comply

with Standard No. 204.

D. Cost

The agency believes the cost savings that Volkswagen suggested

would result from excluding vehicles from Standard No. 204

certification are overly optimistic. Vehicle manufacturers would

probably ``piggyback'' tests on a prototype, i.e., the single test of a

prototype vehicle could include indicant tests of Standard Nos. 204,

208, 212, and 301. Therefore, computer modeling and piggyback testing

would significantly reduce this cost burden, especially during the

vehicle developmental phase.

E. Offset Testing Program

In response to IIHS' urging that NHTSA pursue offset testing, the

agency notes that an offset testing program is part of the Standard No.

208 Upgrade program, one of the elements in NHTSA's Strategic Execution

Plan. Additionally, on January 2, 1998, the Center for Auto Safety

(CAS) submitted a petition for rulemaking, requesting the addition of

an offset test requirement within Standard No. 208.

The agency's FY 1997 and FY 1998 appropriations included funding to

work on establishing a frontal offset crash protection safety standard.

NHTSA will analyze the steering column behavior in offset crashes as

part of this effort. The issues raised by IIHS and CAS, of whether to

include a steering column displacement restriction within the

requirements of an offset test standard, will be included in the offset

program decision-making process.

IV. Agency Decision

In the final rule (March 19, 1997; 62 FR 12960) enhancing

manufacturers' abilities to depower air bags, NHTSA decided to allow

the sled test as a temporary measure given the need to provide

manufacturers with maximum flexibility to respond rapidly to the risk

posed by air bag activation in low speed crashes. In the final rule's

preamble, NHTSA discussed the disadvantages of the sled test as an

indicator of real world performance, including the fact that the sled

test does not evaluate ``the steering column's energy absorbing

characteristics and load bearing capability.'' (62 FR at 12966). Sled

testing effectively removes the measurement of the stability of the

steering column as a factor affecting measured levels of occupant

protection performance. NHTSA has never proposed to exclude from

Standard No. 204 vehicles whose certification of compliance with

Standard No. 208 was based upon the sled test or the belted barrier

test.

NHTSA understands that almost all the vehicle manufacturers are now

certifying compliance with Standard No. 208 based on the sled test,

instead of the unbelted frontal barrier test. Further, the

manufacturers have

[[Page 38802]]

indicated that they will continue to rely on the sled test option while

it remains available.

The March 19, 1997, final rule provided that the sled test option

would expire on September 1, 2001. Several petitions for

reconsideration have been filed requesting the agency to extend that

date or to make the option permanent. NHTSA is currently considering

those petitions. In addition, as part of its advanced air bag

rulemaking, the agency is considering the possibility of requiring some

form of barrier test.

Based on these understandings, NHTSA is terminating rulemaking to

exclude from Standard No. 204 vehicles that comply with Standard No.

208. Given that the vehicle manufacturers are expected to rely on the

sled test (to meet Standard No. 208 requirements) for the next several

years, there is no need during that period for an exclusion from

Standard No. 204 for vehicles certified to Standard No. 208 based on

the barrier test. If circumstances change in the future, the agency

will consider appropriate action at that time.

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

delegations of authority at 49 CFR 1.50 and 501.8)

Issued on: July 14, 1998.

L. Robert Shelton,

Associate Administrator for Safety Performance Standards.

[FR Doc. 98-19217 Filed 7-17-98; 8:45 am]

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