[Federal Register Volume 63, Number 138 (Monday, July 20, 1998)]
[Proposed Rules]
[Pages 38797-38799]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-19154]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
Denial of Petition for Rulemaking; Federal Motor Vehicle Safety
Standards
AGENCY: National Highway Traffic Safety Administration (NHTSA),
Department of Transportation.
ACTION: Denial of petition for rulemaking.
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[[Page 38798]]
SUMMARY: This document denies Mr. John K. Roberts' petition to amend
Federal Motor Vehicle Safety Standard (FMVSS) No. 108, Lamps,
reflective devices, and associated equipment, to add requirements
regarding the maximum time for a stop lamp to reach 90 percent of its
required illumination. A requirement of this nature could be met using
currently-available technology such as light emitting diodes (LEDs),
neon lamps, hot filament systems, or shuttered systems. However, the
costs associated with such a requirement would be far in excess of its
benefits.
FOR FURTHER INFORMATION CONTACT: Mr. Chris Flanigan, Office of Safety
Performance Standards, NHTSA, 400 Seventh Street, SW, Washington, DC
20590. Mr. Flanigan's telephone number is: (202) 366-4918. His
facsimile number is (202) 366-4329.
SUPPLEMENTARY INFORMATION: By letter dated March 29, 1997, Mr. Roberts
petitioned the agency to amend FMVSS No. 108 to create a stop lamp
``rise time'' requirement. He suggested that the standard require stop
lamps to reach 90 percent of their presently-required intensity within
75 milliseconds (ms) following actuation. Conventional incandescent
lamps take about 250 ms to reach 90 percent of their required
intensity. In an emergency stop situation, this decrease in
illumination time would allow an extra fraction of a second
(approximately \1/6\th of a second), for a following driver's brake
actuation time.
Vehicle manufacturers could meet this requirement by using one of
four currently available technologies. LED and neon lamps, which are
both used on current vehicles, could meet the requirement as suggested
by Mr. Roberts. These types of lamp systems can illuminate to 90
percent of their required intensity in well under 75 ms. Another method
of meeting the suggested requirement would be to use a hot filament
incandescent lamp. For this type of system, a conventional incandescent
lamp would be constantly supplied with a low voltage which would not be
enough to illuminate the lamp, but would decrease the illumination
time. This is because the lamp is already supplied with a portion of
the energy required for illumination. Finally, a shuttered light system
could be used to comply. This type of system uses a centralized light
source and individually shuttered fiber optic bundles to distribute and
modulate the light sent to the stop lamps.
Mr. Roberts stated that Standard No. 108 should address the time
lag occurring between the actuation of stop lamps and their rise to
effective levels of intensity. He believes that the demands on a driver
are much greater today than when the standard was promulgated, and
therefore, this aspect of stop lamp systems should be regulated. He
cites several vehicle design trends which lead him to believe that
minimum stop lamp rise times are necessary. These include: enhanced
capability for some vehicles to decelerate abruptly due to improved
brakes, tires, and suspension systems; the use of lighter (and more
electrically resistive) vehicle wiring harnesses to improve vehicle
fuel economy; and increasingly overburdened vehicle electrical supply
systems. He states that a vehicle travels seven meters or nearly 1.5
car-lengths at typical highway speeds during a typical incandescent
lamp's 250 ms rise time.
Agency Position
Based on NHTSA's analyses, the requirement that Mr. Roberts
suggested would produce relatively minor benefits. A May 1993 DOT
report, ``Assessment of IVHS Countermeasures for Collision Avoidance:
Rear end Crashes,'' (DOT HS 807 995) found that both vehicles were
moving in only 25 percent of all rear-end crashes. Further, in only
four percent of these crashes was ``following too closely'' or
``tailgating'' cited as the principal cause. With respect to this one
percent of all rear-end crashes (four percent of 25 percent), Mr.
Roberts' suggestion would only provide a benefit if all the following
conditions were met simultaneously: (1) The following driver is
attentive enough to notice a \1/4\th second decrease in stop lamp
actuation time; (2) the following distance is so short that the
following driver cannot apply the brake fast enough to avoid the
collision; (3) the lead driver decelerates so rapidly that the
following driver cannot apply the brake fast enough to avoid a
collision, and; (4) the following driver applies the brake upon first
seeing the stop lamp without waiting for any additional clues such as
closing distance reduction, lead vehicle pitching, or tire squeal. Even
if all these factors occur, it seems unlikely that even one percent of
all rear end crashes would be eliminated or reduced in severity by such
a requirement.
While there would be some small level of benefits if Mr. Roberts'
suggestion were to be included in the standard, such benefits would be
greatly outweighed by the costs involved. LED, neon, and shuttered
light systems would cost manufacturers upwards of $30 per vehicle. The
least expensive of the four available technologies would be the hot
filament systems. These systems would cost the industry approximately
$15 per vehicle. To incorporate these systems, vehicles would need
extra wiring and circuitry to keep the filament of the incandescent
bulb powered to a level that is just below illumination. Based on an
annual U.S. production of 16,000,000 vehicles, the suggested
requirements would cost at least $240,000,000 per year to vehicle
manufacturers which would be passed on to the consumer. This cost does
not include manufacturer installation and other costs such as
manufacturer and dealer profits. The agency has found in the past that
these costs generally add about 50 percent onto the original equipment
cost. These additional factors thus would raise the cost to the
consumer further. Also, there would be an additional cost incurred by
the consumer due to the extra power required to keep the lamp filaments
constantly powered. This would lead to an increase in fuel consumption.
In order to confirm our belief that the benefits of fast rise brake
requirements would be small, NHTSA analyzed data to compare the crash
involvement of vehicles with LED and neon CHMSLs to similar vehicles
with conventional incandescent CHMSLs. Specifically, Maryland state
files were searched for model year 1994-1996 sport utility vehicles and
vans that were struck in the rear while slowing or stopping. These
types of vehicles were chosen because they had the highest percentage
of vehicles which had LED and neon CHMSLs and were fairly similar in
size. When comparing the crash involvement of LED and neon CHMSL
vehicles to the incandescent CHMSL vehicles, there was no statistical
difference found between designs. This may reflect the relatively small
percentage of the vehicle fleet now in service with LED and neon
CHMSLs, so that no statistically valid study may yet be conducted.
Alternatively, it may be that the effects of lesser rise times do not
show up in crash statistics. Whatever the case, the current data do not
show safety benefits on the road from this technology.
Although the agency does not have data at this time to support such
a requirement, it seems intuitive that there could be some value to a
stop lamp illuminating faster. Because there are potential benefits,
the agency will revisit this issue in the future when there are more
vehicles on the road with LED and neon stop lamps. Based on NHTSA's
examination of recent model year vehicles' CHMSLs, manufacturers are
moving towards using more LED and neon light sources for this
application.
[[Page 38799]]
Further, LEDs are beginning to be used as a light source for the main
stop lamps as well. When the population increases, perhaps this will
give the agency sufficient data to support proposing such a
requirement.
In accordance with 49 CFR part 552, this completes the agency's
review of the petition. The agency has concluded that there is no
reasonable possibility that the amendment requested by the petitioner
would be issued at the conclusion of a rulemaking proceeding.
Accordingly, it denies Mr. Roberts' petition.
Authority: 49 U.S.C. 30103, 30162; delegation of authority at 49
CFR 1.50 and 501.8.
Issued on: July 13, 1998.
L. Robert Shelton,
Associate Administrator for Safety Performance Standards.
[FR Doc. 98-19154 Filed 7-17-98; 8:45 am]
BILLING CODE 4910-59-P
