Federal Motor Vehicle Safety Standards; Occupant Crash Protection |
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Topics: National Highway Traffic Safety Administration, Federal Motor Vehicle Safety Standards
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Barry Felrice
Federal Register
April 26, 1994
[Federal Register: April 26, 1994]
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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