[Federal Register Volume 61, Number 32 (Thursday, February 15, 1996)]
[Rules and Regulations]
[Pages 5949-5955]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 96-3382]
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DEPARTMENT OF TRANSPORTATION
National Highway Traffic Safety Administration
49 CFR Part 571
[Docket No. 92-29; Notice 10]
RIN 2127-AF96
Federal Motor Vehicle Safety Standards; Stability and Control of
Medium and Heavy Vehicles During Braking
AGENCY: National Highway Traffic Safety Administration (NHTSA), DOT.
ACTION: Final rule, petitions for reconsideration.
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SUMMARY: This document responds to petitions for reconsideration of
final rules that amended FMVSS No. 105, Hydraulic Brake Systems, and
FMVSS No. 121, Air Brake Systems, to require medium and heavy vehicles
to be equipped with an antilock brake system (ABS). In response to the
petitions, this document requires continuous power for trailer ABS
systems, in place of the dedicated power and separate ground previously
required, and delays the implementation date for the in-cab trailer
malfunction indicator by four years. It also extends by three years the
period in which exterior ABS failure indicators are required on
trailers.
DATES: Effective Dates: The amendments to 49 CFR 571.121 are effective
March 1, 1997.
Compliance Dates: Compliance with the amendments to paragraphs
S5.1.6.2(b) and S5.2.3.2 of 49 CFR 571.121 will be required on and
after March 1, 2001. Compliance with the amendments to paragraph
S5.1.6.3 for truck tractors will be required on and after March 1, 1997
and for single unit vehicles will be required on and after March 1,
1998. Compliance with the amendments to paragraph S5.2.3.2 will be
required on and after March 1, 2001. Compliance with the amendments to
S5.2.3.3 will be required on and after March 1, 1998.
Petitions for Reconsideration: Any petitions for reconsideration of
this rule must be received by NHTSA no later than April 1, 1996.
ADDRESSES: Petitions for reconsideration of this rule should refer to
the above referenced docket numbers and should be submitted to:
Administrator, National Highway Traffic Safety Administration, 400
Seventh Street, SW., Washington, DC 20590.
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, DC 20590 (202) 366-5278.
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, DC 20590 (202)
366-2992.
SUPPLEMENTARY INFORMATION:
I. Background.
II. Petitions for Reconsideration.
III. NHTSA's Decision and Analysis of Issues.
A. Agency's Decision.
B. Trailer Powering.
1. Background and Previous NHTSA Rulings.
2. Petitions for Reconsideration of December 1995 Final Rule
3. Agency's Decision
C. In-Cab Trailer Malfunction Indicators
D. External Trailer Malfunction Indicators
I. Background
Section 4012 of the Motor Carrier Act of 1991, a part of the
Intermodal Surface Transportation Efficiency Act (ISTEA) of 1991, P.L.
102-240, directed the Secretary of Transportation to initiate
rulemaking concerning methods for improving braking performance of new
commercial motor vehicles, including truck tractors, trailers, and
their dollies. Congress specifically directed that such a rulemaking
examine antilock systems, means of improving brake compatibility, and
methods of ensuring effectiveness of brake timing. The Act required
that the rulemaking be consistent with the Motor Carrier Safety Act of
1984 (49 U.S.C. Sec. 31136) and be carried out pursuant to, and in
accordance with, the National Traffic and Motor Vehicle Safety Act of
1966 (now recodified as 49 U.S.C. Sec. 30101 et seq. (Safety Act)).
On March 10, 1995 (60 FR 13216, 60 FR 13297), NHTSA issued final
rules that required medium and heavy vehicles 1 to be equipped
with an antilock brake system (ABS) to improve their directional
stability and control during braking. The March 1995 final rules also
reinstated stopping distance requirements for air-braked heavy vehicles
and established stopping distance requirements for hydraulic-braked
heavy vehicles.
\1\ Hereinafter referred to as ``heavy vehicles''
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In addition to the ABS requirement, the ABS final rule required
truck
[[Page 5950]]
tractors and other towing vehicles to supply dedicated, full time
electrical power to a trailer ABS and required truck tractors and other
towing vehicles to be equipped with two separate in-cab lamps: one
indicating malfunctions in the towing vehicle ABS and the other
indicating malfunctions in the ABS on one or more towed trailers and/or
dollies. The rule also required all trailers, including dollies,
produced during an eight-year transition period, to be equipped with an
external malfunction indicator. In response to petitions for
reconsideration of these requirements, NHTSA published a final rule on
December 13, 1995 (60 FR 63965) affirming its decision to require these
features.
II. Petitions for Reconsideration of December 1995 Final Rule
NHTSA received petitions for reconsideration of the December 1995
amendments to the final rule from the American Trucking Associations
(ATA) which represents trucking fleets, the National Private Truck
Council (NPTC) which represents private trucking fleets, the Truck
Manufacturers Association (TMA) 2, the Truck Trailer Manufacturers
Association (TTMA) which represents trailer manufacturers, the Heavy
Duty Brake Manufacturers Council (HDBMC) 3 which represents heavy
duty brake component manufacturers, Midland-Grau, Kelsey-Hayes,
Rockwell WABCO, Vehicle Enhancement Systems (VES), AlliedSignal,
General Motors, Ford, and the Recreational Vehicle Industry Association
(RVIA).4
\2\ TMA member companies include Ford, Freightliner, General
Motors, Mack Trucks, Navistar International, PACCAR, and Volvo GM
Heavy Truck.
\3\ HDBMC member companies include Abex, AlliedSignal, Eaton,
Midland-Grau, Ferodo America, Haldex, Lucas, MGM Brakes, Motion
Control/Carlisle, Rockwell, Rockwell WABCO, and Spicer/Dana.
\4\ General Motors, Ford, Kelsey-Hayes, and the RVIA all address
amendments to FMVSS No. 105. In this notice, the agency is
responding to the issues relating to FMVSS No. 121. The agency will
address the petitions raising FMVSS No. 105 issues in a future
notice.
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As did the petitioners for reconsideration of the March 1995 final
rule, all petitioners for reconsideration of the December 1995 final
rule agreed with and supported NHTSA's decision and schedule requiring
all heavy vehicles to be equipped with ABS. ATA, TMA, and TTMA
reference what they refer to as the ATA/TMA/TTMA Industry Consensus
Position ABS Reconsideration petition,5 with which they have
stated their concurrence. The Industry Consensus Position states that
the agency should retain the current overall requirements and timing.
Similarly, TMA stated that its companies ``continue to support the
production, sale, and service of ABS within the specified time
frames.'' Nevertheless, the Industry Consensus Position and each of the
petitioners requested that the agency modify the requirements that
address trailer ABS power and the in-cab trailer malfunction indicator.
Specifically, the Industry Consensus Position is that the agency should
(1) delete the requirement for continuous, dedicated power 6 to
the trailer ABS and replace it with a requirement for continuous power
but no dedicated circuit (with backup power on the stoplamp circuit)
and delete the separate ABS ground requirement, and (2) delay the
effective date for an in-cab trailer warning light, but specify another
date that will accelerate the development of the specific means for
achieving the goal of having that warning light. The petitioners
supporting the Industry Consensus Position explained that the heavy
vehicle manufacturers and users are working together and are committed
to developing and deploying a satisfactory in-cab trailer warning light
within the extended time period requested.
\5\ Hereinafter referred to as ``Industry Consensus Position.''
\6\ The terms continuous power, dedicated power, and connector
are discussed in the next section.
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III. NHTSA's Decision and Analysis of Issues
As explained below, NHTSA has decided to amend FMVSS No. 121
consistent with the Industry Consensus Position and to replace the
requirement for dedicated power to trailer ABS with a requirement for
continuous power. Stoplamp power will continue to be required to
provide back-up power for the ABS. In addition, the agency has decided
to delete the requirement for a separate ABS ground and to allow a
common ground for ABS trailer powering. The agency has also decided to
delay the implemenation date for the in-cab trailer malfunction
indicator until March 1, 2001.
A. Trailer Powering
1. Background and Previous NHTSA Rulings
A trailer's antilock brake system may receive its electrical power
in one of the following ways: (1) intermittent power through the
stoplamp circuit, (2) continuous power through a circuit that is shared
and provides power to more than one electrical component or which is
used to transmit one or more signals, or (3) continuous, dedicated
power through a circuit whose sole function is to provide power to the
trailer ABS. With stoplamp powering, electrical power to the ABS is
only supplied when the brake pedal is applied and the stop lamp switch
is activated. As a result, the trailer ABS must share power with
stoplamp bulbs, which decreases the voltage available for powering the
trailer ABS. With continuous powering, electrical power to the trailer
ABS is present at all times, but other devices could be powered off the
same circuit and multiplexed 7 communication signals could be
carried on the circuit. With dedicated powering, electrical power to
the trailer ABS is present at all times, but no other device can be
powered off this circuit and communications signals cannot be carried
on the circuit.
\7\ Multiplexing is defined by the Society of Automotive
Engineers's (SAE's) Multiplex Subcommittee as ``The process of
combining several messages for transmission over the same signal
path.''
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Trailers do not typically have their own electrical power source.
Thus, an electrical connector is needed to provide electrical current
between a tractor and a trailer. At present, the most common electrical
connector used for this purpose in the United States is the SAE J560
plug/receptacle, which was developed in the 1950s and has been in
widespread use ever since. This connector has seven pins, providing
seven electrical paths: Pin one is used as a common ground for the
other six positive power pins; pin two is used to power clearance and
side marker lamps; pin three is used to power the left hand turn
signal; pin four is used to power the stoplamp; pin five is used to
power the right hand turn signal and hazard signal; pin six is used to
power the taillamp, marker lamps, and license plate lamps; and pin
seven is an auxiliary circuit that is not currently used in most
vehicle combinations. In the past, it has been common practice to power
trailer ABSs exclusively from pin 4, the stoplamp circuit. This
involves sharing power with the stoplamp bulbs which are only activated
when the brakes are applied.
In a fleet study 8 that NHTSA conducted to support the current
ABS rulemaking, the agency evaluated other ABS powering approaches,
including a single 13-pin connector, a separate six-pin connector, and
another separate connector known as the International
[[Page 5951]]
Standards Organization (``ISO'') connector. These other powering
approaches used dedicated electrical circuits, including separate,
fully dedicated positive and ground wires, to power the trailer ABS.
8 ``An In-Service Evaluation of the Performance,
Reliability, Maintainability, and Durability of Antilock Braking
Systems for Semitrailers,'' U.S. Department of Transportation/ NHTSA
Report No. DOT HS 808 059, October 1993
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In the March 1995 final rule, NHTSA decided to require dedicated
powering for trailer ABSs and to require that towing vehicles have a
corresponding separate circuit. (60 FR 13248-13250) The agency
explained that this requirement provides the most dependable source of
electrical power from the tractor to ensure the functioning of the
trailer's ABS.
In petitions for reconsideration of the March 1995 final rule,
American Automobile Manufacturers Association (AAMA), Midland-Grau, and
TTMA requested that NHTSA interpret the requirement for dedicated power
so that the ABS powering circuit need not be exclusively used for ABS.
AAMA and Midland-Grau requested the agency to allow other uses for this
circuit, such as powering interior van trailer lights and multiplex
signaling. ATA reasserted its concern that the requirement for a
separate circuit would be costly and would create operational problems,
because it would result in the use of a second tractor/trailer
electrical connector, which would be used only infrequently, until the
number of tractors and trailers with ABS increased, to the point where
a high percentage of vehicles in combination would be ABS equipped. ATA
stated a strong preference for a requirement that would allow the
continued use of the SAE J560 connector. In a September 6, 1995 letter,
ATA requested that the agency interpret the requirement for a separate
electrical circuit in such a way as to allow the continued use of the
SAE J560 connector.
In the December 1995 final rule responding to petitions for
reconsideration, NHTSA denied the petitioners' request to permit other
uses for the separate ABS circuit. Based on information available at
that time, NHTSA concluded that it was necessary for the ABS on towed
vehicles to receive full-time power through a dedicated circuit to
reduce the possibility of the ABS being inoperative due to lack of
power. The agency found no basis in the publicly available data on
which to alter its view that the dedicated circuit was necessary.
2. Petitions for Reconsideration of December 1995 Final Rule
In response to the December 1995 final rule, each petitioner
supported the Industry Consensus Position to permit continuous powering
to the trailer ABS. TMA stated that new information and industry
commitments support a decision to delete the dedicated powering
requirement and replace it with a continuous powering requirement. TMA,
Midland-Grau, ATA, AlliedSignal, HDBMC, and VES supplied data which
indicated that adequate levels of electrical power could be supplied to
trailer ABSs on non-dedicated circuits. Midland-Grau strongly supported
the continuous powering requirement with the stoplamp circuit as a back
up, provided that the ABS circuit could be used to power warning and
other monitoring systems. ATA supported the Industry Consensus
Position. That organization continues to believe that intermittent
powering through the stoplamp circuit provides adequate electrical
energy to power the trailer ABS, citing its analysis of additional data
and industry commitments to upgrade tractor electrical systems.
Nevertheless, ATA agreed to a requirement for continuous power instead
of stoplamp power, if the trailer ABS power supply circuit could be
used for other purposes.
All petitioners opposed the requirement for dedicated powering with
a separate ground. TMA, ATA, Midland-Grau, AlliedSignal, and HDBMC
stated that the separate ground requirement, which is an integral part
of dedicated powering, requires the use of diodes in the trailer ABS's
electrical control unit (ECU) which reduce the voltage available for
trailer ABS. They further stated that requiring two grounds could
create ``ground loop circuits,'' which may create unexpected voltage
differences between various electrical systems on vehicles. This may
result in electrical shorting and the possibility of electrical fires.
In support of their petitions, the petitioners provided new
information relating to the voltage requirements of the new generation
of ECUs, the amperage requirements of new modulators, and the voltage
losses associated with dedicated power circuits. The petitions also
stated that the petitioners are committed to meeting new voluntary
powering standards and to completing the development of a new
generation of electronic communications systems.
3. Agency's Decision
The agency's decisions are based on the new information provided in
the public record by the petitioners, as described above and discussed
more fully below. Based on this information, as well as recent studies
9 by the agency, NHTSA has decided to amend FMVSS No. 121
consistent with the Industry Consensus Position and to replace the
requirement for dedicated power to the trailer ABS with a requirement
for continuous power. Stoplamp power will continue to be required to
provide back-up power for the trailer ABS. In addition, the agency has
decided to delete the requirement for a separate ABS ground and to
allow a common ground for ABS trailer powering. The agency emphasizes
that continuous power rather than intermittent power through the
stoplamp circuit is needed as a primary powering source to ensure the
safe operation and reliability of trailer ABS and to provide the
capability to signal a continuous warning of a trailer ABS malfunction
to the cabs of towing units.
\9\ Winkler, C.B., Bogard, S.E., Bowen, M.A., Ganduri, S.M., and
Lindquist, D.J. ``An Operational Field Test of Long Combination
Vehicles Using ABS and C-Dollies'', University of Michigan
Transportation Research Institute Report No. 95-45-2, under USDOT/
NHTSA Contract No. DTNH22-92-D-07003, November 1995
Flick, M. A., ``NHTSA's Heavy Duty Vehicles Brake Research
Program Report Number 10--Evaluation of Trailer Antilock Braking
Systems Electrical Powering'', USDOT Report No. HS 808 249, March
1995.
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With respect to the safe operation of trailer ABS, an agency report
10 indicated that a problem can occur if power is interrupted to a
trailer ABS while it is cycling. Specifically, under lightly loaded or
empty trailer operating conditions on low coefficient of friction
surfaces, if a brake application that activates the ABS is fully
released and then fully applied again, the resulting interruption of
electrical current through the stoplamp circuit can cause the
reactivated ABS ECU to misinterpret the wheel speed signals it is
receiving. The ECU could interpret the signals as meaning that the
vehicle is stopped and thereupon allow the brakes to be fully applied.
This would result in locked trailer wheels. Notwithstanding the fact
that this type of brake application might occur infrequently in real-
world operating conditions, this possibility underlines the importance
of continuous powering as the primary method of powering trailer ABS,
and indicates that the stoplamp circuit should not be relied on as more
than a back-up to primary continuous powering. Data submitted by
Midland-Grau support the agency's position.
\10\ USDOT Report No. HS 808 249, March 1995.
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With respect to the reliability of trailer ABS, NHTSA's decisions
in earlier rulemakings focused on ensuring that the trailer ABS
received adequate voltage. In the March 1995 final rule,
[[Page 5952]]
the agency specified a requirement for a dedicated trailer ABS power
circuit as the best means to ensure adequate voltage levels (i.e., 9-10
volts) for trailer ABSs. The agency believed that a separate ground
wire was also needed to ensure sufficient capacity to provide a return
path for electrical current that would not be subject to excessive
voltage drops because the ground wire carried too much current. This
belief rested on data from the agency's fleet studies.
On the basis of this new information in the petitions for
reconsideration, NHTSA has determined that a continuous, but non-
dedicated, source of power and a shared ground will provide sufficient
power to the trailer ABS. The HDBMC petition stated that all current
versions of trailer ABSs function at levels as low as 8.5 volts, and
that ABS modulators have now been designed to draw a maximum of 3 amps.
The agency agrees with the HDBMC petition that the information
previously available indicating that trailer ABSs require 9-10 volts to
remain functional, and that ABS modulators draw 2-6 amps of current,
has been superceded. This information about the lower power needs of
new ABS systems indicates that a dedicated power source and a separate
ground wire are not necessary for ABS power.
The agency agrees with petitioners that the addition of a separate
ground wire would necessitate adding diodes to the trailer ECU powering
circuitry to prevent inadvertent ground loops that may result in
electrical short circuits or electrical fires. These added diodes would
result in a 0.7 volt decrease to the trailer ECU, an outcome
inconsistent with ensuring adequate power levels.
Based on the above considerations, NHTSA has decided to modify
sections 5.1.6.3 and 5.5.2 to require continuous power to trailer ABSs,
to permit the circuit to be shared with other devices and to allow
trailer ABS powering circuits to share a common ground with other
electrical powering circuits.
Powering electrical devices other than the trailer ABS from the ABS
power circuit has the potential to compromise the circuit's ability to
power the trailer ABS. A recently completed study on long combination-
unit vehicles (LCVs) 11 highlights the need to design all the
elements of tractor/trailer electrical system to ensure adequate
electrical power levels. Among other things, that study considered
whether sufficient voltage could be supplied to the rear trailers and
dollies of multiple trailer combinations (especially triple trailer
combinations) on the same circuit. The study found that even with
special wiring and well maintained connectors, it was necessary for the
electrical systems of tractors to supply 13.3 volts and for the ABS on
dollies and trailers to operate on no more than 9.0 volts in order to
ensure that sufficient electrical power could be supplied. Some of the
tractors in the test program were not able to consistently provide the
13.3 volts of electrical power through the stoplamp circuit, and some
of the ABSs needed more than 9.0 volts. In some cases, trailing unit
ABSs ceased functioning. Accordingly, a manufacturer can ensure
adequate powering for trailer ABSs by providing adequately sized
electrical wiring in both towing and towed units, by providing towing
units with heavy duty electrical charging systems, and by employing low
voltage demand lighting systems.
\11\ University of Michigan Transportation Research Institute
Report No. 95-45-2, under USDOT/NHTSA Contract No. DTNH22-92-D-
07003, November 1995
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The agency agrees with Midland-Grau's position that the only other
devices which should share this circuit are warning, monitoring, or
other signaling/communications devices. Additional uses that would not
likely pose problems are low power demand components or devices which
are powered when the vehicle is stopped or in reverse, conditions in
which the ABS would not be in use. However, the agency has decided not
to specify the devices that may share the use of the trailer ABS power
circuit. The agency is confident heavy vehicle manufacturers and users
recognize the need for appropriate restrictions and notes that industry
is working, through various SAE and other technical committees, to
establish performance standards for electrical systems that power
tractor and trailer ABS systems. These anticipated industry standards
are expected to include objective performance test procedures,
measurement criteria, and, in some cases, target performance levels.
Several of the petitioners specifically referenced SAE J2272, Truck
Tractor Power Output for Trailer ABS, and its TMC equivalent, RP137,
Antilock Electrical Supply for Tractors Through the SAE J560 Connector,
and indicated that they were committed to designing and using products
that meet these specifications. TTMA stated that it was developing a
comparable companion standard for trailer electrical systems.
NHTSA will monitor these efforts to develop consensus industry
standards and the commitment made by heavy vehicle manufacturers and
users to meet these voluntary standards. Efforts to develop consensus
on this topic have been under way since 1988, when WABCO submitted a
petition on trailer ABS powering schemes (53 FR 39751, October 12,
1988). The agency anticipates that this powering issue can be resolved
without further delays in the implementation schedule for the trailer
powering and in-cab indicator requirements.
After evaluating these voluntary standards, NHTSA may consider
further rulemaking to amend FMVSS No. 121 to require minimum voltage
levels at the tractor or to limit the use of the ABS power circuit if
such requirements appear necessary to ensure the adequacy of power to
the trailer ABS. Such a rulemaking action would be consistent with the
President's Regulatory Reinvention Initiative which encourages
regulatory agencies, when appropriate, to adopt voluntary standards
established and followed by the private sector.
B. Trailer Malfunction Indicators
FMVSS No. 101, Controls and Displays, sets forth requirements for
the location, identification, and illumination of motor vehicle
controls and displays. Table 2(a) of the standard lists various
telltales that are required in a motor vehicle to advise the driver of
the status of a variety of vehicle systems. For air brake equipped
trucks, these include telltales for brake system air pressure and for
ABS malfunction in the truck.
In the March 1995 final rule, NHTSA required lamps in the cab of
truck tractors to indicate any malfunction with the ABS of any towed
vehicles. (60 FR 13244, 13245) The agency also required trailers to
supply trailer ABS malfunction signals to the tractor. The agency
explained that it is essential that a driver be notified about an ABS
malfunction in the trailer, so that the problem can be corrected. The
agency cited results from the ABS fleet study which indicated that
drivers are more likely to observe a tractor in-cab indication of a
trailer ABS malfunction than they are a trailer-mounted lamp. The study
also noted that some trailer ABS malfunctions were present for a long
time, and not reported, because the drivers did not notice that the
trailer-mounted malfunction lamps were activated. Based on these
findings, the agency decided that it was necessary to require an in-cab
trailer ABS malfunction warning light to adequately ensure that such
malfunctions would be detected and corrected.
In response to the March 1995 final rule, ATA petitioned the agency
to delete the requirement for in-cab indication of trailer ABS
malfunctions.
[[Page 5953]]
It argued that such a requirement was unnecessary and would needlessly
complicate the electrical system of the tractor and the electrical
connector arrangement between tractors and trailers.
In the December 1995 final rule, NHTSA denied ATA's request to
delete the in-cab malfunction lamp for the trailer ABS. In explaining
that the in-cab trailer malfunction lamp is necessary, the agency
referenced a study that showed that an in-cab malfunction lamp is a
more effective means of making the driver aware of an ABS malfunction,
compared with an external malfunction lamp on the trailer.12 NHTSA
also disagreed with ATA's statement that the requirement for two
malfunction indicators unreasonably complicates the electrical systems
in combination vehicles, based on comments by brake and vehicle
manufacturers stating that it was appropriate to have an indicator in
the towing unit cab.
\12\ ``An In-Service Evaluation of the Performance, Reliability,
Maintainability, and Durability of Antilock Braking Systems for
Semitrailers,'' U.S. Department of Transportation/NHTSA Report No.
DOT HS 808 059, October 1993.
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In response to the December 1995 final rule, the Industry Consensus
Position stated that ultimately it is essential to provide drivers an
in-cab indication of a trailer(s) ABS malfunction, but that requiring
the in-cab indicator by 1997 would likely impede the implementation of
a new high speed data transmission protocol SAE J1939 that is now being
developed by the SAE. This new protocol is expected to become the
recognized method for providing signaling capability between tractors
and trailers for a wide variety and number of devices and systems,
including trailer ABS malfunction indications. The Industry Consensus
Position is that delaying the implementation date of the in-cab
malfunction warning requirement for trailer ABS malfunctions to March
1, 2001, would provide sufficient time to fully develop the SAE J1939
protocol and would thus preclude the need for a two-step implementation
process.
Based on information provided in the petitions, NHTSA has decided
to grant the requested delay for the trailer in-cab malfunction
indicator. By delaying the requirement, the agency will enable the
manufacturers to move directly and promptly to in-cab failure
indicators that will use the new SAE protocol, thereby saving the cost
of installing indicators based on current technology. The delay will
also avoid the compatibility problems between new and old tractors and
trailers in the field and the associated costs and potential
maintenance problems associated with such a transition. The petitions
indicate a strong commitment to develop an SAE J1939-based final
solution. The agency anticipates that heavy vehicle manufacturers and
users will be able to develop and implement SAE J1939 and that further
delays in the implementation of this requirement will neither be
requested nor necessary.
NHTSA further notes that the external trailer indicator will still
advise a driver about a trailer ABS malfunction during this interim
period, when an in-cab indicator is not required. Notwithstanding the
need to rely on the external trailer indicator during this interim
period, NHTSA continues to view the in-cab trailer ABS malfunction
indicator as the best method for informing a driver of a trailer ABS
malfunction, based on the data and other information referenced in the
final rule.
C. External Trailer Malfunction Indicator
In previous notices, NHTSA emphasized the interrelationship between
the in-cab trailer malfunction indicator and the external trailer
malfunction indicator. In the September 28, 1993, notice of proposed
rulemaking (60 FR 13221, September 28, 1993) which led to the March
1995 final rule, the agency stated that the eight-year period for the
interim external trailer requirement was intended to represent the
average lifespan of a truck tractor and that
The external lamp would not be necessary on new trailers
manufactured after the end of that period because by that time, a
significant majority of tractors in the heavy vehicle fleet, which
would be responsible for the vast majority of miles driven by
tractors, would be manufactured in compliance with the requirement
for an in-cab lamp capable of receiving a malfunction signal from a
trailer.
In the final rule, the agency reiterated this view, although it
talked in terms of ``ABS and non-ABS equipped tractors'' as a shorthand
for tractors equipped with ABS malfunction indicators.
NHTSA's decision to delay the in-cab malfunction indicator for
trailer ABS from March 1, 1997 until March 1, 2001, will delay the
entry of tractors equipped with such indicators into the fleet. To
provide drivers of tractors without in-cab indicators with a warning of
trailer ABS failure, the agency has decided to extend the transition
period during which a trailer must be equipped with an external
malfunction indicator. The external indicators will be required from
March 1, 1998 until March 1, 2009, three years later than the date
established in the December 1995 final rule. Accordingly, a trailer
must still be equipped with an external ABS indicator during the time
period in which there is no in-cab trailer ABS malfunction indicator
requirement in effect as well as for an additional eight years after
the in-cab trailer malfunction indicator requirement takes effect. As
explained in previous notices, the additional eight-year transition
period represents the typical life cycle of tractors. Based on these
considerations, NHTSA has decided to amend S5.2.3.3 to require each
trailer (including a trailer converter dolly) manufactured on or after
March 1, 1998 and before March 1, 2009 to be equipped with an external
ABS malfunction indicator lamp.
IV. Rulemaking Analyses and Notices
A. Executive Order 12866 and DOT Regulatory Policies and Procedures
This notice has not been reviewed under Executive Order 12866.
NHTSA has considered the impacts of this rulemaking action and
determined that it is not ``significant'' within the meaning of the
Department of Transportation's regulatory policies and procedures. In
connection with the March 1995 final rules, the agency prepared a Final
Economic Assessment (FEA) describing the economic and other effects of
this rulemaking action. Summary discussions of those effects were
provided in the ABS final rule. For persons wishing to examine the full
analysis, a copy is in the docket.
The amendments in this final rule do not make those effects any
more stringent, and in some respects make it easier for a manufacturer
to comply with them. Specifically, by eliminating the requirement for
the dedicated ABS circuit and delaying the trailer in-cab malfunction
indicator by four years, tractor and trailer manufacturers will be able
to develop new methods of communicating trailer ABS information to the
tractor. Thus, for these four years, tractor manufacturers will not
have to provide a trailer in-cab malfunction indicator. After this four
year period, truck and trailer manufacturers will incur some additional
cost associated with ABS communications. This cost will depend on the
communication technique employed, i.e., multiplexing, Radio Frequency
(RF) signaling, or a separate circuit.
B. Regulatory Flexibility Act
NHTSA has also considered the effects of both this final rule or
the original final rule under the Regulatory Flexibility Act. I hereby
certify that it will not have a significant economic impact on a
substantial number of small
[[Page 5954]]
entities. Accordingly, the agency has not prepared a final regulatory
flexibility analysis.
NHTSA concluded that the March 1995 final rule had no significant
impact on a substantial number of small entities. Thus, the revised
final rule, which temporarily reduces costs associated with the March
1995 final rule, will not have a significant economic impact on a
substantial number of small entities.
C. National Environmental Policy Act
NHTSA has analyzed this rulemaking action for the purposes of the
National Environmental Policy Act. The agency has determined that
implementation of this action will not have any significant impact on
the quality of the human environment.
D. Executive Order 12612 (Federalism)
NHTSA has analyzed this action under the principles and criteria in
Executive Order 12612. The agency has determined that this notice does
not have sufficient Federalism implications to warrant the preparation
of a Federalism Assessment. No State laws will be affected.
E. Civil Justice Reform
This final rule does not have any retroactive effect. Under 49
U.S.C. 30103, 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. 49 U.S.C. 30161 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.
List of Subjects in 49 CFR Part 571
Imports, Motor vehicle safety, Motor vehicles, Rubber and rubber
products, Tires.
In consideration of the foregoing, the agency is amending Standard
No. 121, Air Brake Systems, in title 49 of the Code of Federal
Regulations at part 571 as follows:
PART 571--[AMENDED]
1. The authority citation for part 571 continues to read as
follows:
Authority: 49 U.S.C. 322, 30111, 30115, 30117, and 30166,
delegation of authority at 49 CFR 1.50.
2. Section 571.121 is amended by revising S5.1.6.2(b), S5.1.6.3,
S5.2.3.2, S5.2.3.3 and S5.5.2 to read as follows:
Sec. 571.121 Standard No. 121; Air brake systems.
* * * * *
S5.1.6.2 Antilock malfunction signal.
* * *
(b) Each truck tractor manufactured on or after March 1, 2001, and
each single unit vehicle manufactured on or after March 1, 2001, that
is equipped to tow another air-braked vehicle, shall be equipped with
an electrical circuit that is capable of transmitting a malfunction
signal from the antilock brake system(s) on one or more towed
vehicle(s) (e.g., trailer(s) and dolly(ies)) to the trailer ABS
malfunction lamp in the cab of the towing vehicle, and shall have the
means for connection of this electrical circuit to the towed vehicle.
Each such truck tractor and single unit vehicle shall also be equipped
with an indicator lamp, separate from the lamp required in S5.1.6.2(a),
mounted in front of and in clear view of the driver, which is activated
whenever the malfunction signal circuit described above receives a
signal indicating an ABS malfunction on one or more towed vehicle(s).
The indicator lamp shall remain activated as long as an ABS malfunction
signal from one or more towed vehicle(s) is present, whenever the
ignition (start) switch is in the ``on'' (run) position, whether or not
the engine is running. The indicator lamp shall also be activated as a
check of lamp function whenever the ignition is turned to the ``on'' or
``run'' position. The indicator lamp shall be deactivated at the end of
the check of lamp function unless a trailer ABS malfunction signal is
present.
* * * * *
S5.1.6.3 Antilock power circuit for towed vehicles. Each truck
tractor manufactured on or after March 1, 1997, and each single unit
vehicle manufactured on or after March 1, 1998, that is equipped to tow
another air-braked vehicle shall be equipped with one or more
electrical circuits that provide continuous power to the antilock
system on the towed vehicle or vehicles whenever the ignition (start)
switch is in the ``on'' (run) position. Such a circuit shall be
adequate to enable the antilock system on each towed vehicle to be
fully operable.
* * * * *
S5.2.3.2 Antilock malfunction signal. Each trailer (including a
trailer converter dolly) manufactured on or after March 1, 2001, that
is equipped with an antilock brake system shall be equipped with an
electrical circuit that is capable of signaling a malfunction in the
trailer's antilock brake system, and shall have the means for
connection of this antilock brake system malfunction signal circuit to
the towing vehicle. The electrical circuit need not be separate or
dedicated exclusively to this malfunction signaling function. The
signal shall be present whenever there is a malfunction that affects
the generation or transmission of response or control signals in the
trailer's antilock brake system. The signal shall remain present as
long as the malfunction exists, whenever power is supplied to the
antilock brake system. Each message about the existence of such a
malfunction shall be stored in the antilock brake system whenever power
is no longer supplied to the system, and the malfunction signal shall
be automatically reactivated whenever power is again supplied to the
trailer's antilock brake system. In addition, each trailer manufactured
on or after March 1, 2001, that is designed to tow another air-brake
equipped trailer shall be capable of transmitting a malfunction signal
from the antilock brake system(s) of additional trailers it tows to the
vehicle towing it.
* * * * *
S5.2.3.3 Antilock malfunction indicator. In addition to the
requirements of S5.2.3.2, each trailer (including a trailer converter
dolly) manufactured on or after March 1, 1998, and before March 1,
2009, shall be equipped with an external indicator lamp that is
activated whenever there is a malfunction that affects the generation
or transmission of response or control signals in the trailer's
antilock brake system. The indicator lamp shall remain activated as
long as such a malfunction exists, whenever power is supplied to the
antilock brake system. Each message about the existence of such a
malfunction shall be stored in the antilock brake system whenever power
is no longer supplied to the system, and the malfunction signal shall
be automatically reactivated when power is again supplied to the
trailer's antilock brake system. The indicator lamp shall also be
activated as a check of lamp function whenever power is supplied to the
antilock brake system and the vehicle is stationary. The indicator lamp
shall be deactivated at the end of the check of lamp function unless
there is a malfunction or a message about a malfunction that existed
when power
[[Page 5955]]
was last supplied to the antilock brake system.
* * * * *
S5.5.2 Antilock system power--trailers. On a trailer (including a
trailer converter dolly) manufactured on or after March 1, 1998 that is
equipped with an antilock system that requires electrical power for
operation, the power shall be obtained from the towing vehicle through
one or more electrical circuits which provide continuous power whenever
the powered vehicle's ignition (start) switch is in the ``on'' (run)
position. The antilock system shall automatically receive power from
the stoplamp circuit, if the primary circuit or circuits are not
functioning. Each trailer (including a trailer converter dolly)
manufactured on or after March 1, 1998 that is equipped to tow another
air-braked vehicle shall be equipped with one or more circuits which
provide continuous power to the antilock system on the vehicle(s) it
tows. Such circuits shall be adequate to enable the antilock system on
each towed vehicle to be fully operable.
* * * * *
Issued on: February 12, 1996.
Ricardo Martinez,
Administrator.
[FR Doc. 96-3382 Filed 2-13-96; 8:45 am]
BILLING CODE 4910-59-P
