Federal Motor Vehicle Safety Standards; Occupant Crash Protection

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket No. 74-14; Notice 88]

RIN 2127-AE48

Federal Motor Vehicle Safety Standards; Occupant Crash Protection

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

ACTION: Notice of proposed rulemaking.

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SUMMARY: This notice proposes to require Type 2 safety belts either to

be integrated with the vehicle seat or to provide a means of

adjustability to improve the fit and increase the comfort of the belt

for a variety of different sized occupants. NHTSA believes that some

occupants who find their safety belts to be uncomfortable, either wear

their safety belts incorrectly or do not wear their safety belts. NHTSA

believes that improving safety belt fit will encourage the correct use

of safety belts and could have the potential to increase the overall

safety belt usage rate.

DATES: Comment Date: Comments on this notice must be received by NHTSA

not later than June 27, 1994.

Effective Date: If adopted, the proposed amendment would become

effective September 1, 1996.

ADDRESSES: Comments should refer to the docket and notice number set

forth in the heading of this notice and be submitted to: NHTSA Docket

Section, room 5109, 400 Seventh Street SW., Washington, DC 20590. The

NHTSA Docket Section is open to the public from 9:30 am to 4 pm Monday

through Friday.

FOR FURTHER INFORMATION CONTACT: Mr. Clarke Harper, Frontal Crash

Protection Division, Office of Vehicle Safety Standards, NRM-12, 400

Seventh Street SW., Washington, DC 20590. Mr. Harper can be reached by

telephone at (202) 366-4916.

SUPPLEMENTARY INFORMATION:

Background

Section 2503(4) of the ``Intermodal Surface Transportation

Efficiency Act of 1991'' requires the NHTSA to address the matter of

improved design for safety belts (Pub. L. 102-240). In response to this

statutory mandate, NHTSA issued an advance notice of proposed

rulemaking (ANPRM) on May 29, 1992 (57 FR 22687). The ANPRM listed

three rulemaking options and posed ten questions. The options included:

A. Take No Regulatory Action at This Time.

B. Adopt Detailed Regulatory Requirements to Ensure Proper Belt Fit.

C. Adopt a General Requirement that Safety Belts Adjust to Fit

Different Sized Occupants.

The ten questions asked for information on costs and benefits, and

for comments on the test procedure. The ANPRM also included a

discussion of the types of complaints the agency receives concerning

belt fit. Finally, the ANPRM explained that any proposal addressing

safety belt fit will encourage the correct use of safety belts and

could have the potential to increase safety belt use. Of those persons

who currently do not use safety belts because of improper fit, some

would respond to the improved fit by beginning to use their belts or by

wearing them more frequently.

Research

Since the ANPRM, the agency has conducted research on the issue of

safety belt fit. A detailed discussion of this research can be found in

a technical paper titled ``Improved Design for Safety Belts,'' a copy

of which has been placed in the docket for this rulemaking. For this

paper, the agency surveyed eight vehicles with non-adjustable shoulder

belts and seven vehicles with various types of adjustable shoulder

belts to determine how well the belts fit a family of dummies (the six-

year-old, the 5th percentile female, the 50th percentile male, and the

95th percentile male). The survey used the comfort zone described in

the ANPRM (Option B), modified as appropriate for the different sized

dummies.

In the vehicles with non-adjustable shoulder belts, the belt was

within the comfort zone 32.3 percent of the time for the six-year-old

dummy, 94.3 percent for the 5th percentile female, 51.2 percent for the

50th percentile male, and 57.1 percent for the 95th percentile male.

For the adult dummies, these results do not correlate with the pattern

of belt fit complaints received by the agency. The complaints are often

from shorter adults, suggesting that height may not be the only factor

that affects safety belt fit. For example, the agency observed that,

for two persons of the same height, the belt path was higher

(approaching the neck) on the person with a larger torso. The agency

also observed that belts tend to ride higher on the torso as the

relative position of the belt anchorage and seat are changed so that

the anchorage is farther to the rear in relation to the seat. This

movement of the belt occurs because the belt tends to seek the

straightest line path between its anchorages.

In vehicles with adjustable shoulder belts, the belts were within

the comfort zone 33.3 percent of the time for the six-year-old dummy,

95 percent for the 5th percentile female, 85.7 percent for the 50th

percentile male, and 100 percent for the 95th percentile male. These

results show that currently available adjustable shoulder belt designs

do improve safety belt fit for adults. The significantly lower

percentage of both non-adjustable and adjustable belts within the

comfort zone for the six-year-old dummy suggests that additional means,

such as booster seats, are necessary for comfortable belt fit for such

persons. Booster seats will raise the proper fit to over 80 percent.

The agency also considered the effectiveness of integrating safety

belts into seats to provide the necessary comfort. During the research,

the agency was able to gain access to only a single vehicle equipped

with an integrated safety belt: The Mercedes Benz 500SL convertible.

This particular system also included an upper adjustable anchorage on

the seat. The survey of adult human subjects indicated the safety belt

did fit the range of adult occupants.

The vehicles with adjustable shoulder belts were also surveyed

using live test subjects having the approximate physical dimensions of

the six-year-old, 5th percentile female, 50th percentile male, and 95th

percentile male dummies. The six-year-old human test subject reported a

good fit 10.5 percent of the time, and the 50th percentile male test

subject 95.7 percent of the time, while the 5th percentile female and

95th percentile male test subjects reported a good fit 100 percent of

the time. These results also support the agency's conclusion that

adjustable shoulder belts can fit a wide range of adult occupants.

Comments on the ANPRM

The agency received 33 comments in response to the ANPRM. In

general, the commenting manufacturers did not support continuation of

this rulemaking, while commenting consumer advocates believed that the

agency should address the issue of belt fit. Commenters did not provide

any information on potential benefits other than anecdotal information

from consumer surveys.

A number of questions were raised concerning the test procedure for

Option B. Some commenters stated that it was not appropriate to test

the six-year-old dummy in the driver's seat. Other commenters stated

that the 95th percentile adult male dummy might not fit in some rear

seats. A number of comments were also received concerning the

positioning procedures for the dummies.

Commenters also raised questions concerning the test zone described

in the ANPRM. NHTSA reviewed the test zone as part of the research

described above and found that the shoulder zone was redundant and the

chest zone was mislocated on some dummies (e.g., the chest zone

intersected the neck of the six-year-old dummy). Therefore, for the

research, the sternum reference point and the width of the shoulder

zone were modified for each dummy, using the sitting height listed in

S7.1.3 of Standard No. 208 as a guide to adjust the measurement in

reference to the 50th percentile male dummy.

Some commenters expressed concern that attempts to improve seat

belt fit through providing means of adjustability could lead to

misadjustment of belts, which could, in turn, increase the potential

for injury. The agency conducted dynamic sled tests simulating a 48.3

km/h barrier impact using adjustable shoulder belts that were

improperly positioned. In some cases dummy measurements improved, while

in other cases measurements were worse. However, it should be stressed

that these results were based on an adjustable belt range of

approximately 16 centimeters, which is much greater than the adjustment

available in current vehicles or that is required by this proposal. At

this time, the agency does not have any information on the effect of an

adjustment in the 5 centimeter range on dummy measurements.

Proposal

After reviewing the comments and the research results, NHTSA has

tentatively concluded that belts which provide better fit, would, in

turn, promote increased belt usage. Accordingly, the agency is

proposing to require Type 2 safety belts either to be integrated with

the vehicle seat or provide a means of adjustability to improve the fit

and increase the comfort of the belt for a variety of different sized

occupants.

The agency has decided not to propose detailed requirements. First,

the detailed test procedure in the ANPRM would not provide an adequate

means of identifying improper fit on the wide variety of sizes and

shapes of vehicle occupants. As discussed above, the agency research

showed that the proposed test procedure, using test dummies, had a much

different result than the comfort levels reported by human subjects

during the research survey. The human adults were more comfortable with

the safety belt fit than the dummy fit indicated. Conversely, the human

child discomfort and misfit were much worse than the dummy fit

indicated.

Next, the results of the agency's research lead to the conclusion

that currently available non-adjustable belts fit small adults better

than they fit large adults. This does not correlate well with the

complaints received by the agency. For these reasons, the agency does

not believe that the test procedure suggested in the ANPRM addresses

the cause of real-world fit problems. In addition, comments to the

ANPRM raised a number of unresolved questions concerning the test

procedure. These include a potentially uncomfortable location of the

test zone on human subjects, the need to develop positioning procedures

for the various dummies, and the need to develop and add specifications

for the 5th percentile female and 95th percentile male dummies in 49

CFR Part 572.

The agency has examined a number of different vehicles that provide

some means of adjusting the shoulder belt portion of the safety belt.

For example, Volvo offers a design in which the shoulder belt webbing

is fed through a slot in the pillar at different angles as increasing

amounts of webbing are spooled off the retractor. A number of

manufacturers offer a design in which the upper anchorage can be

manually moved vertically to a set number of positions. Mercedes Benz

offers similar designs which adjust automatically as either the seat or

head rest position is adjusted. Another design used to maintain proper

shoulder belt position is a design in which the inboard anchorage is

mounted on the seat and moves with the seat, while the outboard

anchorage is mounted on the vehicle chassis. Some manufacturers have

chosen to use both an upper adjustable anchorage and an inboard movable

anchorage on the same safety belt. NHTSA believes that all of these

designs offer good degrees of adjustment.

In addition, some manufacturers have safety belts integrated with

the seats. While the anchorages for these belts are not adjustable,

this type of belt appears to provide a good fit for a wide range of

occupants because the upper and lower anchorages maintain a constant

position relative to the seat and the occupant, regardless of the seat

adjustment. As a result of being on the seat, the upper anchorage is

typically farther forward relative to the occupant than is the upper

anchorage for belts that are neither adjustable nor integrated. As a

result, the belt does not ride as high as it attempts to seek the

straightest line between the anchorages. As discussed previously in

this notice, the agency's research noted this problem with belt

anchorages that were far behind the occupant. Therefore, NHTSA is

proposing that a Type 2 safety belt must either be equipped with an

adjustable anchorage or be integrated with the seat.

Some commenters stated that a general requirement that belts be

adjustable would not be effective because it would allow manufacturers

to call any design with any degree of movement an ``adjustable'' belt.

They could do this even if the amount of adjustability did not improve

safety belt fit for many occupants. NHTSA has observed some safety belt

designs that might be considered meeting a broad definition of

``adjustable'' (e.g., rotating D-rings), but which NHTSA believes do

not offer sufficient adjustment to ensure that the belts would fit a

wide range of occupants. Agency research found that on eight different

designs of upper adjustable anchorages, the overall anchorage travel

ranged from 5.8 centimeters to 10.1 centimeters. For inboard movable

anchorages, the anchorages all moved more than 19 centimeters, always

the entire distance of seat travel. Conversely, the rotating D-rings

provide no travel. Therefore, the value of five centimeters appears to

be a reasonable lower limit for anchorage adjustment. For this reason,

NHTSA is specifying that manufacturers installing a means of adjustment

must use designs that provide at least five centimeters of

adjustability. NHTSA believes that all of the effective designs

discussed above provide at least this amount of adjustment.

Most of the adjustable belts currently available are installed at

front seating positions. For the rear seats, NHTSA is aware of General

Motor's ``Child Rerouter.'' This design utilizes a clip through which

the shoulder belt can be routed to change the shoulder belt angle.

NHTSA is also aware of the integrated safety belt on the rear seat of

the Volvo 850 station wagon. Also, a few Mercedes Benz models (300S,

300SE) incorporate automatically adjusting shoulder anchorages in the

rear seat. NHTSA requests comments on various designs that may be used

to comply with the proposed requirements in the rear seats, the

practicability of these designs, and the costs of these designs. NHTSA

requests comments on the need for better belt fit for adults at rear

seating positions.

As discussed previously in this notice, NHTSA's research shows that

this requirement alone will not be sufficient to address belt fit

problems of small children. The agency believes that the need exists

for the use of belt-positioning child booster seats or another means of

achieving a good fit, adjustability of the safety belt alone is not

sufficient. The agency has recently published an NPRM, also mandated by

the ``Intermodal Surface Transportation Efficiency Act of 1991,'' to

address issues related to belt-positioning child booster seats (58 FR

46928; September 3, 1993). The NPRM proposed to amend Standard No. 213,

``Child Restraint Systems,'' to permit the manufacture and sale of

belt-positioning seats by removing the impediments in the current

standard to the production of these seats. The proposal included a test

procedure and labeling/informational requirements. The comments

received on that notice are currently being evaluated by the agency.

NHTSA also requests comments on the regulatory language proposed in

this notice. Are there any safety belt designs that adjust to fit a

wide range of occupants but which might not be considered as complying

with this proposal? Is there any design that could fall within the

language of the proposal but which a commenter believes should not be

allowed because it does not fit a sufficiently wide variety of

occupants? NHTSA requests that commenters address both why a design

does (or doesn't) comply with the proposed requirements and why the

design should (or shouldn't) be allowed.

NHTSA discussed in the ANPRM the increased number of complaints

concerning safety belt fit in recent years. The agency stated improving

safety belt fit should increase belt usage and that increased usage

would, in turn, yield safety benefits. At the same time, the agency

noted that there might be adverse safety consequences if belts were not

adjusted by each successive user to provide the appropriate fit. NHTSA

asked whether it was possible to quantify the benefits of a rule on

improved safety belt fit, and specifically whether any relevant studies

or other data were available. The agency did not receive any data or

analysis regarding the issue of benefits.

Accordingly, NHTSA again asks commenters to address this issue.

Would the rule lead to an increase in belt usage? Would the rule result

in a reduction in belt misuse? For example, would it reduce the

instances in which occupants place the shoulder belt portion of a lap/

shoulder belt behind their backs or under their arms? What would be the

net effect of the rule on safety? What relevant studies and data exist?

For example, do vehicle manufacturers have any information showing a

decrease in complaints about safety belt fit after vehicle models have

been equipped with adjustable shoulder belts?

NHTSA believes that occupants need to have information available on

the proper use of belt adjustment devices. However, NHTSA also believes

that the new labeling requirements for air bags should be the focus for

information in the vehicle. Therefore, NHTSA is not proposing a

requirement to label vehicles but is proposing instead to require

information instructions on proper use in the owner's manual for

vehicles with manually adjustable belts. Because the occupant does not

have to take any action to ensure proper fit, devices which provide

automatic adjustment, including integrated seats, would not need such

instructions. In addition, NHTSA is not proposing specific language for

this requirement as NHTSA believes that manufacturers are in the best

position to determine the best means of providing this information.

If adopted, the agency proposes to make this amendment effective

September 1, 1996. NHTSA believes many vehicles, currently or in the

near future, will comply with this safety belt comfort and fit

requirement to satisfy consumer demand. Additionally, this date is

concurrent with the beginning of the required phase-in of manual safety

belts and air bags. Manufacturers will be able to take advantage of the

redesign process necessary for the air bag requirement to also make any

design changes necessary to comply with this safety belt fit

requirement. Considering these two factors, the agency believes that

two years leadtime would be sufficient.

Rulemaking Analyses and Notices

Executive Order 12866 and DOT Regulatory Policies and Procedures

NHTSA has considered the impact of this rulemaking action under

E.O. 12866 and the Department of Transportation's regulatory policies

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

``Regulatory Planning and Review.'' This action has been determined to

be ``significant'' under the Department of Transportation's regulatory

policies and procedures. NHTSA estimates that the annual economic

impact of this proposed rule would be between $69 and $92 million. The

range reflects cost estimates from NHTSA and the manufacturers,

respectively, and baseline use of technologies as of model year 1992

vehicles. The cost estimates assume adjustable upper anchorages will be

used in the front seat of 4-door vehicles and other vehicles with B-

pillars close to the front seat occupant (e.g., pickups and vans), and

seat-frame-mounted anchorages for the front seat of 2-door vehicles.

Child rerouters are assumed to be used in the rear seats of all

vehicles with rear seating positions. If all occupants that currently

wear their belt incorrectly wore their belt correctly, an estimated 33

lives could be saved and 833 moderate to critical injuries could be

reduced annually.

Regulatory Flexibility Act

NHTSA has also considered the impacts of this notice under the

Regulatory Flexibility Act. I hereby certify that this proposed rule

would not have a significant economic impact on a substantial number of

small businesses. Few, if any, of the vehicle manufacturers qualify as

small entities. To the extent that any affected parties would qualify

as small businesses, the economic impacts associated with this proposal

would not be significant, as explained above.

Paperwork Reduction Act

In accordance with the Paperwork Reduction Act of 1980 (Pub. L. 96-

511), there are no requirements for information collection associated

with this proposed rule.

National Environmental Policy Act

NHTSA has also analyzed this proposed rule under the National

Environmental Policy Act and determined that it would not have a

significant impact on the quality of the human environment.

Executive Order 12612 (Federalism)

NHTSA has analyzed this proposal in accordance with the principles

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

proposed rule would not have sufficient federalism implications to

warrant the preparation of a Federalism Assessment.

Civil Justice Reform

This notice does not have any retroactive effect. Under section

103(d) of the National Traffic and Motor Vehicle Safety Act (Safety

Act; 15 U.S.C. 1392(d)), whenever a Federal motor vehicle safety

standard is in effect, a State may not adopt or maintain a safety

standard applicable to the same aspect of performance which is not

identical to the Federal standard, except to the extent that the State

requirement imposes a higher level of performance and applies only to

vehicles procured for the State's use. Section 105 of the Safety Act

(15 U.S.C. 1394) sets forth a procedure for judicial review of final

rules establishing, amending or revoking Federal motor vehicle safety

standards. That section does not require submission of a petition for

reconsideration or other administrative proceedings before parties may

file suit in court.

Submission of Comments

Interested persons are invited to submit comments on the proposal.

It is requested but not required that 10 copies be submitted.

All comments must not exceed 15 pages in length. (49 CFR 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 for the proposal 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 received too

late for consideration in regard to the final rule will be considered

as suggestions for further rulemaking action. Comments on the proposal

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.

List of Subjects in 49 CFR Part 571

Imports, Motor vehicle safety, Motor vehicles.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

In consideration of the foregoing, it is proposed that 49 CFR Part

571 be amended as follows:

1. The authority citation for part 571 of title 49 would continue

to read as follows:

Authority: 15 U.S.C. 1392, 1401, 1403, 1407, delegation of

authority at 49 CFR 1.50.

2. Section 571.208 would be amended by designating existing S7.1.2

and S7.1.3 as S7.1.3 and S7.1.4 and adding a new S7.1.2 to read as

follows:

Sec. 571.208 Standard No. 208, Occupant Crash Protection

* * * * *

S7.1.2 Except as provided in S7.1.2.1 and S7.1.2.2, for each Type

2 seat belt assembly which is required by Standard No. 208 (49 CFR

571.208), the upper anchorage, or the lower anchorage nearest the

intersection of the torso belt and the lap belt, shall include a

movable component which provides a minimum of two adjustment positions.

The distance between the geometric center of the movable component at

the two extreme adjustment positions shall be not less than five

centimeters, measured linearly. If the component must be moved

manually, information shall be provided in the owner's manual to

explain how to adjust the seat belt and warn that misadjustment could

reduce the effectiveness of the safety belt in a crash.

S7.1.2.1 An integrated Type 2 seat belt assembly is not required

to comply with the requirements of S7.1.2. A Type 2 seat belt assembly

is considered an integrated assembly if the seat frame is part of each

of the seat belt assembly anchorages, as defined in S3 of Standard No.

210 (49 CFR 571.210).

S7.1.2.2 As an alternative to meeting the requirement of S7.1.2, a

Type 2 seat belt assembly shall provide a means of automatically moving

the webbing in relation to either the upper anchorage, or the lower

anchorage nearest the intersection of the torso belt and the lap belt.

The distance between the midpoint of the webbing at the contact point

of the webbing and the anchorage at the extreme adjustment positions

shall be not less than five centimeters, measured linearly.

* * * * *

Issued on: April 21, 1994.

Barry Felrice,

Associate Administrator for Rulemaking.

[FR Doc. 94-10056 Filed 4-25-94; 8:45 am]

BILLING CODE 4910-59-P