[Federal Register Volume 61, Number 135 (Friday, July 12, 1996)]
[Proposed Rules]
[Pages 36698-36702]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-17750]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 93-94; Notice 3]
RIN 2127-AE47
Federal Motor Vehicle Safety Standards; Antilock Brake Systems
for Light Vehicles
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Advance notice of proposed rulemaking (ANPRM); Deferral of
rulemaking.
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SUMMARY: This document defers a rulemaking proceeding in which the
agency is considering whether to require light vehicles (those with a
gross vehicle weight rating (GVWR) equal to or less than 10,000 lbs.)
to be equipped with antilock braking systems (ABS). This rulemaking
proceeding was mandated by the National Highway Traffic Safety
Administration Authorization Act of 1991, which directed the agency to
consider the need for any additional brake performance standards for
passenger cars, including antilock brake standards. The agency believes
it would be inappropriate at this time to require ABS for light
vehicles for the following reasons: Most studies that have analyzed the
accident involvement experiences of ABS-equipped light vehicles have
found mixed patterns, with a reduction in accidents in some crash modes
and an increase in accidents in other crash modes; even without a
Federal requirement, a significant majority of light vehicles will be
voluntarily equipped with ABS; and requiring ABS on those light
vehicles that will not be equipped with ABS would result in significant
costs that, on balance, cannot be justified at this time.
FOR FURTHER INFORMATION CONTACT:
For non-legal issues: Mr. Robert M. Clarke, Office of Crash
Avoidance, National Highway Traffic Safety Administration, 400 Seventh
Street, SW., Washington, D.C. 20590 (202) 366-5278.
[[Page 36699]]
For legal issues: Mr. Marvin L. Shaw, NCC-20, Rulemaking Division,
Office of Chief Counsel, National Highway Traffic Safety
Administration, 400 Seventh Street, SW., Washington, D.C. 20590 (202)
366-2992.
SUPPLEMENTARY INFORMATION:
Table of Contents
I. Background
A. Advance Notice of Proposed Rulemaking and Comments to that
Notice
B. NHTSA Evaluation of the Performance of Light Vehicles
Equipped with ABS
C. Other Studies about the Effectiveness of Light Vehicle ABS
II. NHTSA's Decision to Defer Rulemaking
A. Studies Evaluating the Accident Involvement of Light Vehicle
ABS
B. Market Trends
C. Cost Implications
I. Background
A. Advance Notice of Proposed Rulemaking and Comments to That Notice
This rulemaking proceeding to consider the need for any additional
brake performance standards for passenger cars, including antilock
brake standards, was mandated by the National Highway Traffic Safety
Administration Authorization Act of 1991 (Public Law 102-240, December
18, 1991). On January 4, 1994, the National Highway Traffic Safety
Administration (NHTSA) issued an advance notice of proposed rulemaking
(ANPRM), soliciting comments about whether rulemaking was warranted to
require that all light vehicles (i.e., those with a gross vehicle
weight rating (GVWR) of 10,000 lbs. or less) be equipped with antilock
braking systems (ABS) (59 FR 281). The ANPRM also posed a number of
questions relative to the regulatory approaches that might be employed
if requirements were imposed; the types of performance tests that might
be used; varieties of ABSs that might be appropriate; and regulatory
implementation strategies and schedules that might be employed if
requirements were established.
NHTSA received over 140 comments in response to the docket, the
majority of which were from private citizens relating their experiences
with ABS-equipped light vehicles. Other commenters included vehicle
manufacturers (American Honda, BMW, Chrysler, Ford, General Motors,
Mazda, Mitsubishi, Nissan, Porche, Subaru of America, Toyota, and
Volkswagen) and brake manufacturers (AlliedSignal, ITT Teves of Germany
(ITT Teves), ITT Automotive, and ABS Tech Sciences). Other
organizations that commented included Advocates for Highway and Auto
Safety (Advocates), the American Automobile Association (AAA), the
Insurance Institute for Highway Safety (IIHS), the National School
Transportation Association (NSTA), and the American Coalition for
Traffic Safety.
Commenters expressed differing opinions about whether all light
vehicles should be equipped with ABS. Toyota, ITT Teves, AlliedSignal,
AAA, the NSTA, Edge Diagnosis Systems, and approximately 35 percent of
the private citizen respondents stated that light vehicles should be
required to be equipped with ABS. Nissan, Honda, Chrysler, Mitsubishi,
Ford, Subaru, Volkswagen, Mazda, and IIHS, and approximately 65 percent
of the private citizen respondents believed that equipping light
vehicles with ABS should remain an optional choice for consumers. GM
and BMW stated that they were not opposed to a requirement for ABS but
indicated that additional information should be obtained before the
agency made such a decision.
Commenters supporting a requirement that light vehicles be equipped
with ABS offered the following reasons:
Equipping light vehicles with ABS would increase vehicle
safety and enhance correct brake usage.
Equipping light vehicles with ABS would improve lateral
stability and steerability, and enhance braking performance.
A requirement would eliminate an indefinite transition
period for light vehicles to ABS. They believed that a protracted
transition period would create the possibility of increased risks to
drivers, especially for those who operate light vehicles with and
without ABS brake systems.
Additionally, 31 private citizens commented about their positive
experience with ABS-equipped light vehicles, such as near-miss crashes.
Commenters opposing a requirement that light vehicles be equipped
with ABS offered the following reasons:
Consumer demand for advanced safety systems including ABS
is sufficient to encourage manufacturers to offer the systems.
Equipping light vehicles with ABS should not be required
until data conclusively demonstrate that ABS-equipped light vehicles
are involved in fewer and less severe crashes.
The costs associated with requiring that all light
vehicles be equipped with ABS would increase the costs associated with
purchasing new light vehicles. This added cost might discourage
potential buyers of new light vehicles from purchasing other, optional
improved safety features of new vehicles.
Not all consumers need their light vehicles to be equipped
with ABS, based on either their driving habits or the types of roads
and/or road conditions they typically encounter.
Twenty-four private citizens submitted comments citing unfavorable
experiences with their ABS-equipped light vehicles. These incidents
typically involved braking on surfaces with low coefficients of
friction. It appears that the drivers incorrectly assumed the ABS would
help them stop in shorter distances. These commenters cited additional
reasons why they think ABS on light vehicles should remain optional,
including concerns that:
A requirement would add significant costs, thereby
lowering the affordability of less expensive vehicles. This would
create an incentive for consumers to keep their older, potentially less
safe, vehicles longer.
Insurance industry studies showing no reductions in the
number of insurance claims or costs per claim for ABS-equipped light
vehicles, compared to non-ABS-equipped light vehicles, do not support a
requirement for ABS on such vehicles.
Repairs of ABS on light vehicles could be expensive which
could result in some consumers deciding not to repair these systems.
There are too few instances where equipping a light
vehicle with ABS would be useful.
The brake pedal pulsation and system noise, evident when
some systems activate, could frighten or distract drivers.
Average drivers lack the skill to capitalize on the main
benefit of ABS, the ability to execute aggressive crash-avoidance
steering maneuvers.
B. NHTSA Evaluations of the Performance of Light Vehicles Equipped With
ABS
The January 1994 ANPRM referenced test track evaluations of ABS-
equipped light vehicles,1 including a December 1991 report which
describes tests conducted on ten light vehicles to evaluate the
improvement in braking performance and vehicle stability and control
resulting from ABS. The test program's purpose was to show the degree
to which an ABS improves a light vehicle's braking performance. Among
the principal findings in the
[[Page 36700]]
report were that each ABS, and especially all-wheel systems, improved
the light vehicle's lateral stability during panic braking, and that
the all-wheel systems shortened stopping distances on most hard paved
surfaces, with improvements of between 25 to 50 percent on wet
surfaces.
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\1\ Hiltner, Arehart, and Radlinski, ``Light Vehicle ABS
Performance Evaluation,'' DOT HS 807 813, December 1991; and ``Light
Vehicle ABS Performance Evaluation--Phase II,'' DOT HS 807 924, May
1992.
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A May 1992 report described tests conducted on eight light vehicles
to evaluate how the ABS influenced vehicle stopping distance and
lateral stability and control on various surfaces. Among the report's
principle findings were that seven of the eight vehicles were under
complete directional control during the tests with ABS ``on,'' and that
ABSs improved stopping performance on all surfaces, except for stops on
dry gravel surfaces.
In 1994, NHTSA issued a third report evaluating ABS
performance.2 On February 9, 1995, NHTSA published a notice
requesting comments about this report. (60 FR 7814). The report
evaluated the accident rates of ABS-equipped cars currently on the road
and compared them to the accident rates of similar cars without ABS.
The principal findings of and conclusions of this report were that (1)
ABS reduced the involvements of passenger cars in multi-vehicle crashes
on wet roads by 14 percent and reduced those involving fatalities by 24
percent, (2) ABS had little effect on multi-vehicle crashes on dry
roads, (3) ABS reduced the risk of fatal collisions with pedestrians by
27 percent in ABS equipped passenger cars, (4) run-off-road crashes
(e.g., rollovers, side and front impacts with fixed objects) increased
by 19 percent for nonfatal crashes and 28 percent for fatal crashes,
and (5) the overall, net effect of light vehicle ABS on both fatal and
nonfatal accidents was close to zero.
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\2\ Kahane, C. Preliminary Evaluation of the Effectiveness of
Antilock Brake Systems for Passenger Cars (DOT Rep. No HS 808 206).
Washington, DC: National Highway Traffic Safety Administration.
(1994)
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NHTSA received comments about this study from Volkswagen, the
American Automobile Manufactures Association (AAMA), the National
Automobile Dealers Association (NADA), General Motors, and Advocates.
The commenters generally believed that the NHTSA study should not be
considered definitive until additional studies and analysis have been
conducted. Volkswagen, NADA, GM, Toyota, and Advocates supported
NHTSA's efforts to conduct additional research and to educate the
driving public on the advantages and limitations of ABS. GM, Toyota,
and NADA agreed with several hypotheses presented by NHTSA to explain
why ABS, which clearly improves vehicle performance in controlled
maneuvers, appeared to have minimal effect in reducing overall crash
rates. In contrast, Advocates disagreed with the agency's risk
compensation and driver error hypotheses as possible explanations for
why ABS-equipped cars have more run-off-the-road crashes. Advocates
also stated that these findings indicate that vehicle platforms need to
be redesigned to prevent rollover crashes, since ABS often will not
prevent such crashes.
C. Other Studies About the Effectiveness of Light Vehicle ABS
In addition to NHTSA's efforts, several other organizations have
evaluated the effectiveness of light vehicle ABS. Studies conducted by
the Insurance Institute for Highway Safety (IIHS), which compared
insurance claims for 1991 and 1992 model year cars with and without
ABS, showed no reduction in claims for cars equipped with ABS.3
Another study 4 based its conclusions on the same set of data
collected by HLDI, yielding similar findings.
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\3\ Highway Loss Data Institute. Collision and Property Damage
Liability Losses of Passenger Cars With and Without Antilock Brakes.
(Research Report HLDI A41). Arlington, VA (1994, January).
4 Insurance Institute for Highway Safety. (1994,
January). ``Antilocks May Not Make the Difference That Many
Expected.; What Antilocks Can Do, What They Cannot Do.'' Status
Report, 29(2), 1-5, Arlington, VA
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Another study 5 by Evans demonstrated that, although benefits
associated with ABS-equipped light vehicles may not be seen in general,
ABS does have a positive effect in reducing certain types of accidents,
while possibly being associated with increases in others.
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\5\ Evans, L. (1995). ABS and Relative Crash Risk Under
Different Roadway, Weather, and Other Conditions. SAE Paper 950353.
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A recent study by Lau and Padmanaban (1996), reported more
favorable results; namely, that ABS-equipped light vehicles were
experiencing lower overall crash involvement rates.6 However, the
study reported no measurable difference in the rate of involvements in
fatal crashes between light vehicles with and without ABS. The agency
notes that the difference in the finding relative to overall crash
involvement rates, compared to other studies that found no significant
change in crash involvement rates, is primarily the result of different
assumptions about which populations of vehicles were appropriate to
include in the comparison.
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\6\ Lau, E., and Padmanaban, J., Accident Experience of
Passenger Vehicles with Four-Wheel Antilock Braking Systems, Failure
Analysis Associates, Inc., Menlo Park, CA, January 1996.
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II. NHTSA's Decision to Defer Rulemaking
After reviewing the available information, NHTSA has decided to
defer indefinitely its decision about whether to require equipping
light vehicles with antilock braking systems until a later date. The
agency believes it would be inappropriate to currently mandate such a
requirement for the following reasons: (1) most studies that have
analyzed the accident involvement experiences of ABS-equipped light
vehicles have found mixed patterns, with a reduction in accidents in
some crash modes but an increase in accidents in other crash modes, (2)
even without a Federal requirement, a significant majority of light
vehicles will be voluntarily equipped with ABS, (3) and requiring ABS
on those light vehicles that will not be equipped with ABS would result
in significant costs that, on balance, cannot be justified at this
time.
In a separate rulemaking, NHTSA decided to require that medium and
heavy vehicles be equipped with ABS (60 FR 13216, March 10, 1995). The
agency emphasizes that its decision not to require that light vehicles
be equipped with ABS is applicable only to light vehicles and not to
medium and heavy vehicles, and therefore should not be interpreted as
being inconsistent with this earlier decision. The two rulemakings are
readily distinguishable. The studies discussed in today's notice only
studied the accident involvement patterns of ABS on light vehicles;
they did not evaluate the accident involvement patterns of ABS on
medium or heavy vehicles. Tractor trailer combinations are more prone
to loss of stability and control including jackknifing, given that they
have an articulation point. ABS provides more potential benefits for
vehicles, such as medium and heavy ones, which have a greater disparity
between their lightly loaded and fully loaded weights. An out-of-
control medium or heavy vehicle (that can weigh 10,000 to 80,000
pounds) is more dangerous in collisions with other vehicles than an
out-of-control light vehicle.
A. Studies Evaluating the Accident Involvement of Light Vehicle ABS
NHTSA believes that the increased involvements in some crash modes
with ABS equipped light vehicles, especially single vehicle run-off-
road crashes, may be due to a lack of driver knowledge rather than the
performance attributes of ABS. This is consistent with track test
[[Page 36701]]
results, conducted by professional drivers, indicating that ABS-
equipped light vehicles have better stability and control than non-ABS
equipped light vehicles. NHTSA believes that the ability of an ABS-
equipped light vehicle to reduce crashes is linked closely to a
driver's ability to use its performance capabilities. The agency plans
to conduct further analyses to evaluate how driver behavior and
performance affect how well light vehicle ABS reduces crashes.
One possible explanation for the increase in single vehicle run-
off-road accidents may be due to driver steering behavior rather than
the functioning of a light vehicle's ABS.
NHTSA notes that typical panic steering in non-ABS light vehicles
is often characterized by a three-stage maneuver: (1) a large steering
input to avoid a collision with the obstacle; (2) a reverse steering
input to stop lateral deviation and correct for vehicle heading, and 3)
an attempt to regain vehicle control by returning to an appropriate
lane.7 ABS-equipped light vehicles allow drivers the opportunity
to maneuver around an obstacle, while keeping the vehicle under
control, but having such capability does not guarantee a potential
crash will be avoided.
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\7\ Weirwille, W.W., ``Driver Steering Performance,'' in
Automotive Engineering and Litigation, Volume 1, G.A. Peters and
B.J. Peters, Eds., New York, Garland Publishing Co., 1984
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NHTSA has considered certain hypotheses to explain why some drivers
of ABS-equipped light vehicles may leave the road: (1) Some drivers are
unaware of how ABS functions, (2) some drivers do not know how to react
properly to crash threats, and (3) some drivers may drive more
aggressively with ABS.
NHTSA believes that drivers of ABS-equipped light vehicles may
``pump'' their brake pedals in crash-imminent situations, thereby
defeating the purpose of the ABS. Also, when activated, some ABS
systems emit a chattering noise or cause the brake pedal to pulsate,
which could confuse drivers into thinking their brakes have failed.
Other drivers have reported their belief that the ABS-equipped light
vehicle is stopping poorly, because tires on such vehicles do not
squeal.
Some drivers may be oversteering their vehicles in an attempt to
avoid a crash threat, thereby causing the vehicles to lose control and
spin out. Other drivers may purposely steer off the road in crash-
imminent situations, either because they incorrectly see no other
option or because they decide this is their best option. Further, light
vehicle ABS performance in situations where drivers make evasive
maneuvers on loose surfaces such as gravel or grass could exacerbate
drivers' lack of skill when executing extreme braking and steering
maneuvers.
Some drivers may be driving more aggressively because they think
that their ABS equipped light vehicle can stop better. This has been
termed ``risk compensation'' or ``risk homeostasis.''
NHTSA is continuing its efforts to review crash data sets,
individual crash case histories, and other information to evaluate
these hypotheses. Also, the agency has established a sub-group of its
motor vehicle safety research advisory committee to specifically
address this problem. Meanwhile, conclusions regarding the
effectiveness of ABS-equipped light vehicles which are based on the
analysis of currently available accident databases should be viewed
with caution. Given increased driver knowledge and experience with ABS-
equipped light vehicles, the agency believes that the number of crashes
involving such vehicles may decline. In addition, more precise crash
database analysis techniques may shed additional light on these
questions.
B. Market Trends
As for the marketplace, NHTSA notes that there is a strong trend
among vehicle manufacturers to voluntarily equip light vehicles with
ABS in response to significant consumer demand for this technology.
As the data in Table 1 indicate, the percentage of new passenger
cars equipped with four-wheel antilock systems has grown from 3.7
percent in 1989 to 57 percent in 1995. Most manufacturers have publicly
indicated plans to offer ABS as either standard or optional equipment
on nearly all of their passenger car lines within the next three years.
TABLE 1.--Percentage of Passenger Cars Sold in the U.S., Equipped with ABS \1\
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Domestic cars % Import cars %
4WABS 4WABS Total cars % ABS
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1989................................................... 3.7 13.6 6.5
1990................................................... 7.6 21.4 11.1
1991................................................... 14.1 26.0 17.1
1992................................................... 32.2 32.2 32.2
1993................................................... 42.3 37.0 41.2
1994................................................... 57.3 47.6 55.5
1995................................................... 57.1 ................. .................
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\1\ Source: Wards Automotive, 1990-1995.
Similar data for light trucks, as shown in Table 2, indicate even
stronger trends in this regard, with ABS installation rates growing to
84.3 percent by 1994.
Table 2.--Percentage of Light Trucks Sold in the U.S., Equipped With ABS \1\
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Import truck % Domestic truck % Domestic truck %
Model year ABS RWAL \2\ 4WABS Total truck % ABS
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1989................................ -- 59.5 -- --
1990................................ 10.2 77.3 2.1 71.4
1991................................ 41.5 77.1 6.2 77.8
1992................................ 51.6 71.5 11.4 80.1
1993................................ 67.9 52.2 31.9 83.0
1994................................ 66.6 53.0 32.4 84.3
[[Page 36702]]
1995................................ ................. 34.7 56.2
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\1\ Source: Wards Automotive, 1990-1995.
\2\ RWAL=Rear Wheel Antilock System.
Based on this information, NHTSA continues to believe that a
significant majority of the light vehicle fleet will be equipped with
ABS, regardless of whether there is a Federal mandate for such systems.
As a result, light vehicles will benefit from the stability and control
characteristics obtained by equipping such vehicles with ABS.
Accordingly, the agency's decision not to require light vehicles to be
equipped with ABS is based in part on the wide scale voluntary
installation of ABS.
C. Cost Implications
In the January 1994 ANPRM, NHTSA estimated that requiring all light
vehicles to be equipped with ABS would cost approximately $1.04 billion
annually to equip those vehicles that would not voluntarily be
equipped. That notice stated that this cost consists of ABS hardware
costs of $920 million, installation costs of about $80 million, and
increased fuel costs of about $40 million due to a small increase in
vehicle weight. The average retail price of an ABS system to the
consumer was estimated to be $450. This price was based on a cost study
of seven ABS systems entitled ``Evaluation of Costs of Antilock Brake
Systems'' and a markup factor of 1.51. The agency's cost estimate
assumed that all-wheel ABS would be required on all light vehicles. It
projected that all-wheel ABS would be voluntarily installed as standard
equipment in 85 percent of model year 1999 passenger cars. The
remaining 15 percent, or about 1.4 million vehicles, would be equipped
only as a result of this regulatory requirement. However, since the ABS
installation rate for 1995 model year domestic passenger vehicle cars,
as reported in Table 1, was little different from 1994, it appears that
this projected 85 percent voluntary installation rate by 1999 could be
somewhat optimistic. A voluntary installation rate of possibly as low
as 70 percent by 1999 could occur, in which case the remaining 30
percent, or about 2.8 million passenger cars, would be equipped only if
there were a regulatory requirement. Such a higher involuntary ABS
installation rate would increase the estimated annual cost of a
requirement for passenger cars from $710 million to $1,420 million. If
this were to occur, the estimated annual cost for all light vehicles
would increase to $1.75 billion.
The cost estimate also projected that all light trucks would be
voluntarily equipped with ABS by model year 1999/2000, 75 percent of
them having all-wheel systems. Thus, an additional 25 percent of new
light trucks or about 1.5 million vehicles, would be involuntarily
equipped with all-wheel ABS if the agency issued a final rule requiring
this. In this case, all- wheel ABS hardware and installation costs
would be about $200 more than those for rear-wheel systems.
NHTSA believes that the significant costs associated with
manufacturers having to equip approximately 4.3 million additional
vehicles with all-wheel ABS further justifies the agency's decision not
to require light vehicles to be equipped with all-wheel ABS at this
time. The studies discussed above do not support such a Federal
requirement at this time. NHTSA emphasizes that the costs and benefits
associated with light vehicle ABS contrasts sharply with the analyses
the agency conducted for medium and heavy ABS, which determined that
ABS was highly beneficial for such vehicles.
For the reasons set forth above, NHTSA has decided to defer this
rulemaking action indefinitely.
Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;
delegation of authority at 49 CFR 1.50 and 501.8.
Issued on: July 5, 1996.
Barry Felrice,
Associate Administrator for Safety Performance Standards.
[FR Doc. 96-17750 Filed 7-11-96; 8:45 am]
BILLING CODE 4910-59-P
