[Federal Register Volume 62, Number 207 (Monday, October 27, 1997)]
[Proposed Rules]
[Pages 55562-55563]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 97-28417]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 96-41, Notice 02]
RIN AG-38
Federal Motor Vehicle Safety Standards; Lamps, Reflective Devices
and Associated Equipment
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Request for comments; reopening of comment period.
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SUMMARY: This document reopens the comment period for a request for
comments published December 13, 1996, regarding the potential value of
several auxiliary signal lamps in addition to those required by Federal
Motor Vehicle Safety Standard No. 108. One of the commenters provided
NHTSA with a field study of the effectiveness of an ``advance brake
warning system'' (ABWS), one of the auxiliary signal lamps on which
comments were requested. NHTSA believes that this field study is a
significant piece of evidence in reaching any decision about the merits
of ABWS. However, this study only became available just before the
comment period closed. Accordingly, the only commenters that addressed
this field study were the two commenters who filed late comments, as
well as the commenter that provided the field study.
The purpose of this document is to make the public aware of the
field study and to invite comments and analysis of the field study. To
facilitate such comments and analysis from the public, NHTSA is noting
some questions and issues the agency has identified in its review and
analysis of the field study. The comment period is reopened for an
additional 30 days.
DATES: Comments must be received by NHTSA no later than November 26,
1997.
ADDRESSES: Comments should refer to Docket No. 96-41, Notice 2, and be
submitted to: Docket Section, Room 5109, 400 Seventh Street SW.,
Washington, DC 20590 (Docket hours are 9:30 am to 4:00 pm Monday
through Friday).
FOR FURTHER INFORMATION CONTACT: For technical issues: Richard Van
Iderstine, Office of Crash Avoidance Standards, NPS-21, telephone (202)
366-5280, FAX (202) 366-4329.
For legal issues: Taylor Vinson, Office of Chief Counsel, NCC-20,
telephone (202) 366-5263, FAX (202) 366-3820.
Both may be reached by mail at the National Highway Traffic Safety
Administration, 400 Seventh Street, SW., Washington, DC 20590. Comments
should be sent to the Docket Section at the address given above, not
sent or FAXed to these people.
SUPPLEMENTARY INFORMATION: On December 13, 1996, at 61 FR 65510, NHTSA
published a request for comments on whether NHTSA should permit several
types of auxiliary signal lamps in addition to those required by
Federal Motor Vehicle Safety Standard No. 108, Lamps, Reflective
Devices and Associated Equipment (49 CFR 571.108). The agency noted in
this request for comments that these lighting ideas had been submitted
without any data showing that the concepts would produce real safety
benefits on the public roads.
One of the signal lamp ideas on which the agency sought public
comment was an Advance Brake Warning System (ABWS). At present,
vehicles' stop lamps are activated when the driver applies the brakes.
ABWS lights the stop lamps sooner in hard braking than in normal
braking, with the intent of giving following drivers earlier warning.
ABWS does this by activating the stop lamps when a driver rapidly
removes his or her foot from the accelerator pedal, on the assumption
that these rapid removals indicate an intention to apply the brakes.
The 90-day comment period in which the public was invited to
respond to this request for comments closed on March 13, 1997. NHTSA
has received 27 comments in response to this request for comments. In
one of those comments, Baran Advanced Technology Ltd. (Baran), one of
the companies seeking to market ABWS in the United States, provided
NHTSA with a field study conducted in Israel of the crash experience of
vehicles equipped with ABWS. Baran's comment is available to the public
from NHTSA's public docket and has been filed as 96-041-N01-014. This
field study differentiates ABWS from the other signal lamp ideas
discussed in the request for comments, for which there are still no
studies or other data suggesting their effectiveness.
This field study became available only during the last week of the
90-day comment period. Because of this, only three of the 27 comments
addressed this Israeli field study--the commenter that submitted the
study and two organizations that filed comments well after the comment
closing date. Because this field study is important in evaluating the
merits of ABWS, the agency wants to make the public aware of this field
study and ask for public review and comment on the study to help NHTSA
assess the merits of ABWS.
NHTSA has reviewed and analyzed the Israeli field study. The agency
would like to summarize its understanding of the study and identify
some areas in which public comment and additional information might be
helpful. The field study of ABWS involved 764 Israeli government
vehicles tracked over a two-year period. Half the vehicles were
equipped with ABWS, the other half were not. The control group (those
vehicles that did not have ABWS) were matched to the ABWS-equipped
vehicles. That is, each vehicle in the control group was the same make,
model, and model year as a vehicle in the ABWS group.
These 764 vehicles were in a total of 881 crashes, 78 of which were
crashes in which the government vehicle was struck from the rear. Of
these 78 rear-end crashes, 37 occurred in the vehicle fleet equipped
with ABWS, while 41 crashes occurred in the control group. After
adjusting for the distance driven by three particular vehicles, the
study's authors concluded that the rear-end crash involvement rate of
the ABWS equipped vehicles was 17.6 percent less than that of the
control vehicles. In addition, these 78 crashes were then sorted into
``relevant,'' defined in the report as ``crashes in which the
government vehicle was struck from behind while braking or immediately
after braking,'' and ``irrelevant,'' defined in the report as ``crashes
in which the government vehicle was already stopped for a while, or the
driver reported that (s)he decelerated or braked gradually rather than
abruptly, and/or the driver of the striking vehicle testified that he
failed to pay attention to the stopping or stopped vehicle ahead.'' Of
the 78 rear-end crashes, 26 were classified as ``relevant'' and the
other 52 were deemed ``irrelevant.'' The study concluded that the crash
involvement rate of the ABWS-equipped vehicles in relevant rear end
crashes was 64 percent less than that of the control group.
[[Page 55563]]
NHTSA has some concerns about how closely the ABWS group matched
the control group. The Israeli study mentions that vehicle attributes
(make, model, and year) were matched precisely in the ABWS group and
the control group. However, no mention is made of important vehicle use
patterns, such as the driving environment and the typical driver. It
appears that vehicle use patterns were not considered, since no mention
was made in the study of any correlation in these areas.
The report of the Israeli study also presents apparently
conflicting data regarding one important matching vehicle attribute,
the presence of a center high-mounted stop lamp (CHMSL). The report of
the Israeli study states on page 11 that the CHMSL became mandatory in
Israel ``at the end of 1994, for all 1995 passenger vehicles'' and that
``94 of the 764 vehicles had CHMSL.'' However, on page 6, the report
indicates that 153 vehicles were 1995 and 1996 model years. NHTSA would
like to learn from the authors of the report how to explain this
apparent inconsistency.
NHTSA also notes that the analysis of the results appears unusual.
The data collected in the field study showed that there were 417
crashes for the ABWS-equipped vehicles and 464 crashes for the control
group, or 9 percent fewer crashes for the ABWS group. This 9 percent
reduction in crashes for the ABWS-equipped vehicles was found for:
All crashes
Rear-end crashes, and
Crashes other than rear-end crashes
In other words, the ABWS-equipped vehicles in this field study were
just as likely to avoid a frontal or side crash as they were to avoid a
rear crash. Since ABWS would not be visible to the driver of the other
vehicle in a frontal or side crash, there is no apparent reason to
believe that ABWS would have any effect on those types of crashes.
Thus, the data from this study do not appear to show any significant
positive effect for ABWS. However, this simple analysis, which would be
a conventional starting point for many analysts, was not reported in
the study. NHTSA would like to learn why the authors of the report on
the Israeli field study did not include this analysis in the report.
The agency is also interested in commenters' views on how much weight
and significance should be given to the fact that the simplest use of
the data does not indicate any significant effect for ABWS in rear-end
crashes relative to all other types of crashes.
Before making its analyses of ABWS effectiveness, the study
normalized the exposure of the ABWS-equipped vehicles and the control
group of vehicles using just the total miles traveled and time in
service of the vehicles that had experienced rear impacts. Again, the
standard analytical approach is to normalize using the total travel of
the subject groups (all ABWS-equipped vehicles and all the control
group vehicles), which avoids introducing any biases in the results.
The agency is concerned that normalizing only for vehicles in rear-end
crashes may give an unwarranted increase in the observed effectiveness
of ABWS. NHTSA would like to learn why the authors of the study chose
not to use the standard approach and why they believe their alternative
approach avoids any biases. In addition, the agency would like
commenters' views on this technique.
Further, as noted in the study, there was a large difference in the
``relevant'' rear-end crashes for the two groups--18 relevant rear-end
crashes for the control group, but only eight relevant rear-end crashes
for the ABWS group. However, the total rear-end crashes reported were
substantially identical--41 for the control group and 37 for the ABWS
group. The difference of four crashes in this sample size is not
statistically significant. Thus, one interpretation of the data is that
ABWS shifts rear-end crashes from the relevant to the irrelevant
classification without reducing significantly the number of rear-end
crashes. NHTSA would like comments on the appropriate interpretation of
the data.
As part of the public review of the Israeli field study, NHTSA
would like to repeat its previous statements that there are positive
benefits from the current standardization of vehicle signaling systems.
The current signal from stop lamps is a uniform, unambiguous signal
that the driver of the vehicle has applied the brakes. However, the
agency has also indicated that it is conceptually possible that using a
different action to activate stop lamps or having stop lamps send
different signals might offer net safety gains. NHTSA will consider
amending Federal Motor Vehicle Safety Standard No. 108 if it is shown
that a change from the current standardized vehicle signaling systems
would yield a net safety benefit. The agency would like commenters to
address expressly whether the Israeli field study is sufficiently
definitive about net positive safety effects of ABWS that permitting
ABWS can be said to enhance safety even if it detracts from
standardization of vehicle signaling systems.
On September 9, 1997, Baran also submitted an article published in
the journal Human Factors that described a computer simulation study
performed to test the effectiveness of ABWS devices. The principal
author of this article is also the principal author of the report on
the Israeli field study of ABWS. In addition, Baran stated that the
Czech Republic now permits ABWS to be installed on vehicles operating
in that country.
NHTSA is reopening the comment period for an additional 30 days.
The agency would like commenters to focus on ABWS and the materials
that were not available for comment during the previous comment period,
most notably the Israeli field study of ABWS, but also the Human
Factors article. It is not necessary for commenters to resubmit views
and data provided in previous comments to Docket No. 96-41, Notice 1.
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166;
delegations of authority at 49 CFR 1.50 and 49 CFR 501.8
Issued on: October 22, 1997.
James R. Hackney,
Acting Associate Administrator for Safety Performance Standards.
[FR Doc. 97-28417 Filed 10-24-97; 8:45 am]
BILLING CODE 4910-59-P
