Parts and Accessories Necessary for Safe Operation; General Amendments

Note: EPA no longer updates this information, but it may be useful as a reference or resource.

[Federal Register: August 15, 2005 (Volume 70, Number 156)]
[Rules and Regulations]
[Page 48007-48055]
From the Federal Register Online via GPO Access [wais.access.gpo.gov]
[DOCID:fr15au05-12]
[[Page 48008]]

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DEPARTMENT OF TRANSPORTATION
Federal Motor Carrier Safety Administration
49 CFR Parts 390, 392 and 393
[Docket No. FMCSA-1997-2364]
RIN 2126-AA61

AGENCY: Federal Motor Carrier Safety Administration (FMCSA), DOT.
ACTION: Final rule.

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SUMMARY: FMCSA amends part 393 of the Federal Motor Carrier Safety
Regulations (FMCSRs), Parts and Accessories Necessary for Safe
Operation. The amendments are intended to remove obsolete and redundant
regulations; respond to several petitions for rulemaking; provide
improved definitions of vehicle types, systems, and components; resolve
inconsistencies between part 393 and the National Highway Traffic
Safety Administration's Federal Motor Vehicle Safety Standards (49 CFR
part 571); and codify certain FMCSA regulatory guidance concerning the
requirements of part 393. Generally, the amendments do not involve the
establishment of new or more stringent requirements, but a
clarification of existing requirements. This action is intended to make
many sections more concise, easier to understand and more performance
oriented.

DATES: The rule is effective September 14, 2005. The publications
incorporated by reference in this final rule are approved by the
Director of the Office of the Federal Register as of September 14, 2005.

FOR FURTHER INFORMATION CONTACT: Mr. Jeffrey J. Van Ness, Vehicle and
Roadside Operations Division, Federal Motor Carrier Safety Administration,
202-366-0676, 400 Seventh Street, SW., Washington, DC 20590.

SUPPLEMENTARY INFORMATION:

Legal Basis for the Relemaking

This rulemaking is based on the authority of the Motor Carrier Act
of 1935 and the Motor Carrier Safety Act of 1984 (49 U.S.C. 31131 et seq.).
The Motor Carrier Act of 1935, as amended, provides that ``[t]he
Secretary of Transportation (Secretary) may prescribe requirements for:
(1) Qualifications and maximum hours-of-service of employees of, and
safety of operation and equipment of, a motor carrier; and (2)
qualifications and maximum hours-of-service of employees of, and
standards of equipment of, a private motor carrier, when needed to
promote safety of operation.'' (49 U.S.C. 31502(b)).
This final rule amends the Federal Motor Carrier Safety Regulations
(FMCSRs) to remove obsolete and redundant regulations; respond to
several petitions for rulemaking; provide improved definitions of
vehicle types, systems, and components; resolve inconsistencies between
part 393 and the National Highway Traffic Safety Administration's
Federal Motor Vehicle Safety Standards (49 CFR part 571); and codify
certain FMCSA regulatory guidance concerning the requirements of part
393. Generally, the amendments do not involve the establishment of new
or more stringent requirements, but a clarification of existing
requirements. This action is intended to make many sections more
concise, easier to understand and more performance oriented. The
adoption and enforcement of such rules is specifically authorized by
the Motor Carrier Act of 1935. This final rule rests squarely on that
authority.
The Motor Carrier Safety Act of 1984 provides concurrent authority
to regulate drivers, motor carriers, and vehicle equipment. It requires
the Secretary to ``prescribe regulations on commercial motor vehicle
safety.'' The regulations shall prescribe minimum safety standards for
commercial motor vehicles. At a minimum, the regulations shall ensure
that: (1) Commercial motor vehicles are maintained, equipped, loaded,
and operated safely; (2) the responsibilities imposed on operators of
commercial motor vehicles do not impair their ability to operate the
vehicles safely; (3) the physical condition of operators of commercial
motor vehicles is adequate to enable them to operate vehicles safely;
and (4) the operation of commercial motor vehicles does not have a
deleterious effect on the physical condition of the operators' (49
U.S.C. 31136(a)).
This final rule concerns parts and accessories necessary for the
safe operation of commercial motor vehicles. It is based primarily on
section 31136(a)(1) and (2), and secondarily on section 31136(a)(4).
This rulemaking would ensure CMVs are maintained, equipped, loaded, and
operated safely by requiring certain vehicle components, systems and
equipment to meet minimum standards such that the mechanical condition
of the vehicle is not likely to cause a crash or breakdown.
The final rule provides improved guidance concerning parts and
accessories to CMV drivers who are responsible for ensuring vehicles
are in safe and proper operating condition before each trip, and
reporting to their employers any defects or deficiencies observed by,
or reported to, the driver during the work day. By ensuring commercial
motor vehicles are in safe and proper working order, it is less likely
that the mechanical condition of the vehicle would cause a crash or
breakdown. Therefore, drivers' responsibilities for the operation of
their commercial motor vehicles do not, if fulfilled in accordance with
the regulations, impair their ability to operate vehicles safely.
Finally, the rulemaking would ensure the operation of CMVs does not
have a deleterious effect on the physical condition of the operators of
vehicles by requiring vehicle components and systems meet specific
performance requirements. Compliance with these requirements would help
to ensure that the mechanical condition of the vehicle is not likely to
cause a crash or breakdown.
Therefore, FMCSA considers the requirements of 49 U.S.C. 31136
(a)(1), (2) and (4) to be applicable to this rulemaking action. The
rulemaking would amend regulations concerning commercial vehicle
equipment, prescribe regulations applicable to the responsibilities
frequently imposed upon drivers to ensure their ability to operate
safely is not impaired, and help to prevent serious injuries to CMV
drivers that could result from improperly secured loads.
With regard to 49 U.S.C. 31136(a)(3), FMCSA does not believe this
provision concerning the physical condition of drivers is applicable to
this rulemaking because this rulemaking does not concern the
establishment of driver qualifications standards. This final rule
addresses safety requirements applicable to commercial motor vehicle
parts and accessories necessary for safe operation and does not include
issues related to the physical qualifications or physical capabilities
of drivers who must operate such vehicles.
However, before prescribing any such regulations, FMCSA must
consider the ``costs and benefits'' of any proposal (49 U.S.C.
31136(c)(2)(A)).
This final rule requires commercial motor vehicles to be
maintained, equipped and operated safely. It removes obsolete and
redundant regulations; responds to several petitions for rulemaking;
provides improved definitions of vehicle types, systems, and
components; resolves inconsistencies between part 393 and the National
Highway Traffic Safety Administration's Federal Motor Vehicle

[[Page 48009]]

Safety Standards (49 CFR part 571); and codifies certain FMCSA
regulatory guidance concerning the requirements of part 393. The
fundamental purpose of 49 CFR part 393 Parts and Accessories Necessary
for Safe Operation is to ensure that no employer shall operate a
commercial motor vehicle or cause or permit it to be operated, unless
it is equipped in accordance with the requirements and specifications
of this part. However, nothing contained in part 393 shall be construed
to prohibit the use of additional equipment and accessories, not
inconsistent with or prohibited by part 393, provided such equipment
and accessories do not decrease the safety of operation of the motor
vehicles on which they are used. Compliance with the rules concerning
parts and accessories is necessary to ensure vehicles are equipped with
the specified safety devices and equipment.

Background

On April 7, 1997, the Federal Highway Administration (FHWA)
published a notice of proposed rulemaking (NPRM) to amend part 393 (62
FR 18170). FHWA received numerous petitions for rulemaking and requests
for interpretation of the requirements of part 393 which raised the
need for amendments to clarify several provisions of the safety
regulations. In addition, the National Highway Traffic Safety
Administration (NHTSA), the Federal agency responsible for establishing
safety standards for the manufacture of motor vehicles and certain
motor vehicle equipment, made several amendments to its Federal Motor
Vehicle Safety Standards (FMVSSs) that necessitate amendments to the
FMCSRs in order to eliminate inconsistencies between part 393 and the
FMVSSs. Comments were requested by June 13, 1997.

Extension of Comment Period

On June 12, 1997, FHWA published a notice in the Federal Register
to extend the comment period until July 28, 1997 (69 FR 32066). The
extension was in response to a request from the Motor Equipment
Manufacturers Association (MEMA) (62 FR 32066). MEMA requested the
extension in order to develop what it described as ``meaningful and
responsive comments'' to the proposed revisions of Sec. 393.25,
Requirements for lamps other than head lamps, Sec. 393.45, Brake
tubing and hose adequacy, and Sec. 393.46, Brake tubing and hose
connections. A copy of the MEMA request is included in the docket.

Publication of Final Rule on Sec. 393.60, Glazing in Specified Openings

On January 9, 1998, FHWA revised its requirements concerning
glazing materials, windshield condition, coloring and tinting of
windshields and windows, and obstruction to the driver's field of view
for commercial motor vehicles operated in interstate commerce (63 FR
1383). The revision was intended to remove obsolete regulatory
language, establish requirements that were more performance-based than
the previous rules, and respond to requests for waivers to allow the
use of windshield-mounted transponders. The agency had proposed
revising Sec. 393.60 as part of the April 14, 1997, NPRM. Upon review
of the docket comments and requests for waivers, the agency decided to
issue a final rule on glazing materials, windshields and windows and to
publish, at a later date, a final rule on the remaining issues covered
in the NPRM.

Public Meeting About the Proposed Changes to the Brake Hose Regulations

On March 24, 1998, FHWA held a public meeting to discuss
requirements for brake hoses used on commercial motor vehicles. An
announcement of the meeting was published in the Federal Register on
February 20, 1998 (63 FR 8606). Several brake hose manufacturers
submitted comments in response to the 1997 notice of proposed
rulemaking expressing opposition to the proposed changes to Sec. Sec.
393.45 and 393.46. They believe the proposed removal of references to
the Society of Automotive Engineers' (SAE) standards would have an
adverse impact on safety. Some of the brake hose manufacturers
contacted members of Congress to voice their concerns. As a result, the
agency received numerous calls from congressional staff and letters
from members of the House and Senate.
At the request of congressional staff, FHWA met with
representatives from several congressional offices on October 24, 1997,
to explain the proposed rulemaking and the roles of the FHWA and the
NHTSA. During this meeting FHWA offered to hold a public meeting
concerning brake hoses. The meeting was intended to initiate dialogue
between FHWA, NHTSA, manufacturers of brake hoses, brake hose
assemblies, and brake hose end fittings for use on commercial motor
vehicles, and interested parties concerning the adequacy of Federal
requirements for brake hoses and related components. Copies of
presentations made by the participants are included in the docket.
On October 30, 1998, three brake manufacturers, Elf Atochem North
America, Inc., Mark IV Industrial/Dayco Eastman, and Parker Hannifin
Corporation \1\ filed a joint petition for rulemaking with NHTSA. The
petitioners requested that certain requirements relating to brake
hoses, brake hose tubing, and brake hose end fittings that are
administered by FHWA be incorporated into FMVSS No. 106 (49 CFR
571.106). Specifically, the petitioners requested incorporation of the
requirements of 49 CFR 393.45 (Brake tubing and hose, adequacy) and 49
CFR 393.46 (Brake tubing and hose connections) into FMVSS No. 106. On
May 15, 2003, NHTSA published an NPRM proposing amendments to FMVSS No.
106 (68 FR 26384). On December 20, 2004 NHTSA published its final rule
amending FMVSS No. 106 (69 FR 76298).
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\1\ Since the petition was filed with NHTSA, Mark IV Industrial/
Dayco Eastman has been acquired by Parker Hannifin Corporation. Elf
Atochem North America, Inc. was integrated into Atofina Chemical,
Inc. The successor petitioning companies are referred to as Parker/Atofina.
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In consideration of NHTSA's revision of FMVSS No. 106, FMCSA
believes the issues raised by commenters responding to the proposed
revisions to 49 CFR 393.45 and 393.46 have been resolved through
NHTSA's rulemaking.

Discussion of Comments Received in Response to the April 14, 1997, NPRM

The agency received 36 comments in response to the NPRM. The
commenters were: Air Ride Control, Inc.; Amerex Corporation; the
American Trucking Associations (ATA) (two submissions to the docket);
Burns Consulting Associates; Colorado Department of Public Safety;
Commercial Vehicle Safety Alliance (CVSA) (two submissions to the
docket); Robert J. Crail, a transportation engineering consultant; W.
E. Currie, a consulting engineer; Dana Corporation, Boston Weatherhead
Division; Electronic Controls Company; Elf Atochem North America, Inc.;
Georgia Public Service Commission; Grote Industries, Inc.; H[uuml]ls
America, Inc.; Lufkin Trailers; Mark IV Industrial--Dayco Eastman; The
Commonwealth of Massachusetts, Department of Public Utilities; National
Association of State Fire Marshals; National Association of Trailer
Manufacturers; National Automobile Dealers Association; National
Automobile Transporters Association; National Propane Gas Association;
Oklahoma Highway Patrol; Parker Hannifin Corporation (two submissions
to the docket); Rockwell International Corporation (the automotive
division of

[[Page 48010]]

Rockwell is now Meritor Automotive); Star Headlight and Lantern
Company, Inc.; Transportation Safety Equipment Institute; Truck
Manufacturers Association; Truck Trailer Manufacturers Association; UBE
Industries (America), Inc.; Donald H. Verhoff; and, Wells Cargo, Inc.
Of the comments received, 10 focused on the issue of the agency's
proposal to remove references to certain SAE brake hose standards and
recommended practices. Because this issue is being addressed through a
separate rulemaking by NHTSA, FMCSA will not provide a discussion of
brake hose manufacturing standards.
With regard to the remaining comments, the majority of the
commenters supported the proposed amendments. Several, however,
suggested minor enhancements or modifications to the specific wording
proposed by the agency, or changes in terminology. For example, a
transportation engineering consultant suggested we use ``upper beam''
and ``lower beam'' when describing headlight terminology. Along similar
lines, AMERIX Corporation, a fire extinguisher manufacturer, advised us
that the type 4B:C extinguisher referenced in the proposed amendments
to Sec. 393.95 is no longer manufactured.
The National Association of State Fire Marshals (NASFM) argued that
this rulemaking does nothing to address their 1995 petition to amend
the FMCSRs to require fire extinguishers on all lightweight vehicles
(under 10,000 pounds gross vehicle weight rating (GVWR)), operated in
interstate commerce. A copy of the petition was attached. The Agency
previously explained to NASFM that generally, the FMCSRs are not
applicable to lightweight vehicles and that the reference to
lightweight vehicles under 49 CFR 393.95 was an error. The term was
supposed to have been removed when the agency incorporated the
statutory definition of CMV from the Motor Carrier Act of 1984. Fire
extinguishers are required on all power units subject to the FMCSRs,
including vehicles designed or used to transport 9 to 15 passengers
(including the driver), for direct compensation, if the vehicle is
driven more than 75 air miles beyond the driver's normal work reporting
location. This rulemaking was never intended to address this issue.

Amendments to 49 CFR Parts 390, 392 and 393: Section-by-Section
Discussion of the Amendments

Part 390, Subpart A--General Applicability and Definitions

Section 390.5--Definition of Driveaway-Towaway Operation
Parts 393 and 396 of the FMCSRs include several exceptions for
driveaway-towaway operations. Currently, a driveaway-towaway operation
is defined as one in which a motor vehicle constitutes the commodity
being transported and one or more set of wheels of the vehicle being
transported are on the surface of the roadway during transportation.
The driveaway-towaway exceptions are intended to address situations in
which compliance with some of the vehicle regulations is not
practicable because of the circumstances surrounding the delivery or
transportation of the vehicle. Examples of driveaway-towaway operations
include the delivery of a newly manufactured commercial motor vehicle
from a manufacturer to a dealership, the delivery of a new or used
motor vehicle from the dealership to the purchaser, or certain
movements of vehicles to a repair or maintenance facility. Among the
provisions of parts 393 and 396 which do not apply to driveaway-towaway
operations are the requirements for lamps and reflectors, brakes,
driver vehicle inspection reports, maintenance records, and periodic
inspection.
The concept of providing exceptions for such operations dates back
to the former Interstate Commerce Commission's (ICC) May 27, 1939,
Order under Ex-Parte No. MC-2 (14 M.C.C. 669, at 679). A driveaway-
towaway operation was originally defined by the ICC as ``any operation
in which a single motor vehicle or combination of motor vehicles, new
or used, constitutes the commodity being transported and in which the
motive power of any such motor vehicles is utilized.'' In 1952, the ICC
revised the definition to read ``any operation in which any motor
vehicle or motor vehicles, new or used, constitute the commodity being
transported, when one or more set of wheels of any such motor vehicle
or motor vehicles are on the roadway during the course of
transportation; whether or not any such motor vehicle furnishes the
motive power.'' (17 FR 4422, 4423, May 15, 1952).
The current definition of a driveaway-towaway operation was
published on May 19, 1988 (53 FR 18052). FMCSA continues to believe the
definition does not provide sufficient guidance in identifying the
specific types of vehicle operations covered. Therefore, FMCSA revises
the definition of driveaway-towaway operation to limit the use of the
various exceptions to situations in which motor vehicles are being
transported: (1) Between vehicle manufacturer's facilities, (2) between
a vehicle manufacturer and a dealership or a purchaser, (3) between a
dealership, or other entity selling or leasing the vehicle, and a
purchaser or lessee, (4) to a motor carrier's terminal or repair
facility for the repair of disabling damage (as defined in Sec. 390.5)
following a crash, (5) to a motor carrier's terminal or repair facility
for repairs associated with the failure of a vehicle component or
system, or (6) by means of a saddle-mount or tow-bar. In addition, the
driveaway-towaway exceptions are applicable only in those cases where
the motor vehicles are not transporting cargo or passengers. The
revision is intended to reduce confusion and it is responsive to
commenters who requested that the definition include movements of
vehicles between manufacturers' facilities, and the towing of vehicles
after a breakdown.

Part 392, Subpart D--Use of Lighted Lamps and Reflectors

Section 392.33--Obscured Lamps or Reflector
FMCSA amends Sec. 392.33 to include an exception for the
obstruction of trailer conspicuity treatments on the front end
protection device. The NHTSA requires trailer manufacturers to apply
retroreflective sheeting to the front end protection devices or
headerboards of trailers manufactured on or after December 1, 1993 (49
CFR 571.108, S5.7.1.4, entitled location). Because the headerboard is
located at the front of flatbed trailers, the cargo may, depending upon
its height, obstruct the conspicuity material located on the
headerboard. FMCSA recognizes that this temporary obstruction of the
reflective material cannot be avoided in many cases and does not
believe that it is appropriate to penalize motor carriers if this occurs.

Part 393, Subpart A--General

Section 393.1--Scope of the Rules of This Part
FMCSA is revising Sec. 393.1 to clarify the applicability of the
requirements of part 393. Although Sec. 390.3 explains the
applicability of the FMCSRs, and Sec. 390.5 defines the term
``commercial motor vehicle,'' many private motor carriers of property
and private motor carriers of passengers do not understand

[[Page 48011]]

the applicability of the provisions in part 393 when a lightweight
vehicle is used to tow a trailer in interstate commerce. With the
exception of vehicles designed or used to transport 9 to 15 passengers
(including the driver), for direct compensation, more than 75 air miles
beyond the driver's normal work reporting location, and vehicles
transporting certain quantities of hazardous materials, vehicles with a
GVWR below 4,536 kg (10,001 pounds) or designed to transport less than
16 passengers are not subject to the FMCSRs when operated singly in
interstate commerce. However, when a small vehicle is coupled to a
trailer, the gross combination weight rating (GCWR) often exceeds 4,536
kg (10,001 pounds), making the combination subject to the FMCSRs.
Part 393 cross-references several Federal Motor Vehicle Safety
Standards which distinguish between vehicles above and below 4,536 kg
(10,001 pounds) and passenger vehicles designed to transport fewer than
16 passengers. This rulemaking includes numerous proposals to clarify
the cross-references to the FMVSS so that carriers and inspectors can
readily locate the applicable paragraphs within the FMVSSs. The
amendment to Sec. 393.1 is consistent with that goal.
Section 393.5--Definitions
FMCSA is amending Sec. 393.5 by adding definitions of air brake
system, air-over-hydraulic brake subsystem, auxiliary driving lamp,
boat trailer, brake power assist unit, brake power unit, electric brake
system, emergency brake, front fog lamp, hydraulic brake system,
intermodal shipping (cargo) containers, multi-piece windshield, split
service brake system, tow bar, trailer kingpin, vacuum brake system,
and windshield. In addition, the definitions for chassis, clearance
lamp, container chassis, heater, heavy hauler trailer, parking brake
system, side marker lamps (intermediate), and side marker lamps are
revised. The definition of bus is being removed from Sec. 393.5 in
favor of the definition found in Sec. 390.5.
The definitions of brake systems and components make the brake
requirements under subpart C of part 393 easier to understand and enforce.
The definitions of an air brake system and an air-over-hydraulic
brake subsystem are based upon NHTSA's July 18, 1995, final rule on
FMVSS No. 121 (60 FR 36741). The NHTSA amended FMVSS No. 121 to include
a definition of an air-over-hydraulic brake subsystem and to make it
clear that vehicles equipped with such systems are classified as air
braked vehicles. In initially issuing FMVSS No. 121, NHTSA stated that
``it should be noted that the term `air brake system' as defined in the
standard applies to the brake configuration commonly referred to as
`air-over-hydraulic,' in which failure of either medium can result in
complete loss of braking ability.'' (36 FR 3817, February 27, 1971).
Because NHTSA has considered air-over-hydraulic brake systems subject
to FMVSS No. 121 for more than 20 years, FMCSA's adoption of NHTSA's
definitions are not likely to affect the applicability of the brake
requirements under part 393.
The amended definition of a boat trailer is the same as that
contained in 49 CFR Sec. 571.3. The NHTSA defines boat trailer as ``a
trailer designed with cradle-type mountings to transport a boat and
configured to permit launching of the boat from the rear of the
trailer.'' FMCSA includes this definition because Sec. 393.11 includes
requirements for lamps and reflectors on boat trailers.
FMCSA is replacing its definition of ``emergency brake system''
with NHTSA's definition for ``emergency brake.'' This change ensures
consistency between FMCSA's brake regulations covering motor carriers
and NHTSA's regulations covering manufacturers.
The agency is adopting NHTSA's FMVSS No. 105 definition of a split
service brake system and includes it under Sec. 393.5 to improve the
clarity of the hydraulic brake system requirements under subpart C of
part 393.
Definitions of an electric brake system and a vacuum brake system
are added to Sec. 393.5 to support other revisions to the brake system
requirements of part 393. Because there are no FMVSSs which cover
electric and vacuum brake systems, many of the brake requirements under
part 393 are de facto manufacturing standards. To better identify the
applicable requirements, however, the revisions to subpart C
specifically reference electric and vacuum brakes. These definitions
prevent confusion or misunderstandings on the part of motor carriers
and enforcement officials.
With regard to the definition of a chassis, the agency is deleting
the current reference to a ``truck or trailer'' in favor of the term
``commercial motor vehicle,'' which includes trucks, truck tractors,
trailers, buses and converter dollies. This is especially necessary
since the definition of a truck in Sec. 390.5 explicitly excludes
truck tractors.
The definition of a clearance lamp is being replaced with one that
appeared in the Society of Automotive Engineers' definition (Glossary
of Automotive Terms, SP-750, February 1988). Although the SAE
publication is now out-of-print, the Agency continues to believe the
SAE definition provides a better description of the location and
function of the clearance lamps than the current definition in Sec.
393.5.
As for the definition of a heater, FMCSA is amending the reference
to paragraph (1) [the number ``one''] of Sec. 177.834 with a reference
to paragraph (l) [the letter ``l']. The reference to paragraph (1) [the
number ``1''] was a typographical error.
A definition of a trailer kingpin is being added to cover non-
driveaway-towaway operations. Currently, the definition of a saddle-
mount includes a description of a ``king-pin.'' However, this
definition does not appear to be appropriate for the trailer kingpin
nor is the definition the same as that in the SAE's Truck & Bus
Industry Glossary, SP-732, February 1988. Although the SAE publication
is now out-of-print, FMCSA continues to believe the SAE's definition
will ensure that definitions in part 393 are consistent with industry
definitions.
To clarify the applicability of parking brake requirements, the
agency is amending the definition of a parking brake system in Sec.
393.5 to replace the term ``vehicle'' with ``motor vehicle,'' which is
defined in Sec. 390.5.
The agency is amending the definitions of ``side marker lamp
(intermediate)'' and ``side marker lamp'' to include motor vehicles
other than trailers. Currently, both terms are defined only in the
context of trailers. However, side marker lamps are required on almost
all motor vehicles and intermediate side marker lamps are required on
almost all motor vehicles more than 914.4 centimeters (cm) (30 feet) in
length. Therefore, FMCSA is revising the definitions to include trucks,
truck-tractors, and buses and to make both definitions consistent with
the requirements under Sec. 393.11 relating to side marker lamps and
FMVSS No. 108, NHTSA's requirements for lamps and reflective devices.
On November 23, 1990, NHTSA amended its definition of a heavy
hauler trailer to specifically exclude container chassis trailers (55
FR 48850). To maintain consistency between the definitions used by the
FMCSA and NHTSA, FMCSA is amending its definition of a heavy hauler
trailer to exclude container chassis trailers as well.

[[Page 48012]]

Subpart B--Lighting Devices, Reflectors, and Electrical Equipment

FMCSA revises the title of subpart B to read ``Lamps, Reflective
Devices, and Electrical Wiring.'' The new title is more consistent with
the title of FMVSS No. 108, entitled ``Lamps, reflective devices, and
associated equipment.'' The new title would reference electrical wiring
instead of associated equipment because subpart B includes electrical
wiring requirements for several vehicle systems in addition to the
lamps required by FMVSS No. 108.
Section 393.9--Lamps Operable
FMCSA amends Sec. 393.9 to codify regulatory guidance concerning
the use of lamps which are not required by Sec. 393.11 and FMVSS No.
108, and to address obstruction of lamps. Section 393.9 requires that
lamps be capable of being operated at all times. FMCSA has issued
regulatory guidance indicating that Sec. 393.9 is only applicable to
those lamps which are required by the FMCSRs. Therefore, if a motor
carrier installs additional lamps which are found to be inoperable, for
whatever reason, the carrier should not be considered in violation of
Sec. 393.9. FMCSA amends Sec. 393.9 to codify this regulatory guidance.
Section 393.11--Lighting Devices and Reflectors
FMCSA revises the title of Sec. 393.11 to read ``Lamps and
reflective devices'' to maintain consistency between the title for
subpart B and Sec. 393.11. The FMCSA is also amending Sec. 393.11 to
require that commercial motor vehicles manufactured on or after
December 25, 1968, meet the requirements of FMVSS No. 108 in effect at
the time of manufacture, or any subsequent requirements under FMVSS No.
108. Currently, Sec. 393.11 only requires that vehicles manufactured
on or after March 7, 1989, meet the requirements of FMVSS No. 108.
Vehicles manufactured prior to March 7 may meet either FMVSS No. 108 or
the requirements of part 393 in effect on the date of manufacture.
Because NHTSA's FMVSS No. 108 became effective on December 25,
1968, manufacturers have been required to meet these requirements since
that date. FMCSA's reference to March 7, 1989, under Sec. 393.11 is
therefore inappropriate. Vehicles manufactured between December 25,
1968, and March 7, 1989, were originally manufactured to meet FMVSS No.
108, and motor carriers who have maintained lamps and reflectors in the
required locations for these older vehicles would not be affected by
the revision.
In addition, FMCSA revises Sec. 393.11 to provide better guidance
on the requirements for trailers, and to correct several omissions in
Table 1 of that section. The paragraph preceding Table 1 does not
present a clear statement of the requirements for lamps and reflectors.
On December 10, 1992, NHTSA published a final rule requiring that
trailers manufactured on or after December 1, 1993, which have an
overall width of 2,032 mm (80 inches) or more and a GVWR of more than
4,536 kg (10,000 pounds), be equipped on the sides and rear with a
means for making them more visible on the road (57 FR 238). Trailers
manufactured exclusively for use as offices or dwellings are exempt.
NHTSA's rule allows trailer manufacturers to install either red and
white retroreflective sheeting or reflex reflectors. Manufacturers of
retroreflective sheeting or reflectors are required to certify
compliance of their product with FMVSS No. 108 (49 CFR 571.108) whether
the product is for use as original or replacement equipment.
Currently, Sec. 393.11 requires that all lamps and reflective
devices on motor vehicles placed in operation after March 7, 1989, meet
the requirements of FMVSS No. 108 in effect on the date of manufacture.
Therefore, trailers manufactured on or after December 1, 1993, must
have reflective devices of the type and in the locations specified by
FMVSS No. 108. To make certain that all motor carriers operating
trailers subject to the FMCSRs are aware of their responsibility to
maintain the conspicuity treatment, FMCSA is adding detailed language
under Sec. 393.11. FMCSA cross-references the specific paragraphs of
FMVSS No. 108 related to the applicability of NHTSA's trailer
conspicuity standards, the required locations for the conspicuity
material, and the certification and marking requirements.
FMCSA notes that during NHTSA's rulemaking, the issue of requiring
conspicuity material on the rear underride device generated industry
concerns about the maintainability of the retroreflective sheeting in
that location. As stated in the preamble to NHTSA's December 10, 1992,
final rule:

Objections were based on the potential for frequent damage that
would cause trailers in use to fail inspections by [FMCSA]. NHTSA
has observed that the horizontal bar of the underride device is less
subject to docking impacts than the vertical bars because it is
below most dock surfaces (and under a NHTSA proposal [a reference to
the NHTSA's supplemental notice of rulemaking concerning rear impact
guards (57 FR 252, January 3, 1992)]
is even lower). Therefore, the
final rule requires retroreflective material to be applied to the
horizontal device, instead of the vertical ones. NHTSA believes that
the original conspicuity material should have a long useful life on
a large number of trailers, especially if it is applied to a
recessed surface. However, NHTSA recognizes that routine damage, as
a practical matter, may be unavoidable for some trailers as a
consequence of their particular use. Therefore, [FMCSA] will
consider the exclusion of conspicuity treatment from the rear
underride device in any future rulemaking concerning trailer
conspicuity requirements for vehicles subject to 49 CFR 393 Parts
and Accessories Necessary for Safe Operation, and 49 CFR 396
Inspection [,Repair,] and Maintenance.

The cross-reference to NHTSA's conspicuity requirements includes a
reference to the specific paragraphs within FMVSS No. 108 concerning
the locations for the conspicuity treatments. This does not, however,
include an exemption to the requirement that motor carriers maintain
the conspicuity material on the rear underride device.
In addition to providing explicit guidance on trailer conspicuity,
FMCSA amends Sec. 393.11 to codify certain regulatory guidance
concerning the use of amber stop lamps, amber tail lamps, and optical
combinations which would involve the use of amber tail lamps or amber
stop lamps. Motor vehicles are required to be equipped with at least
two red stop lamps and two red tail lamps. However, some motor carriers
have expressed an interest in using additional stop lamps and/or tail
lamps that are amber in color.
Federal Motor Vehicle Safety Standard No. 108 does not allow amber
as an alternate color for a tail lamp. In an August 23, 1990,
interpretation to a manufacturer of lamps and reflectors, NHTSA stated
that ``We have no intention of allowing amber as an alternate color for
a tail lamp.'' In a December 10, 1991, interpretation to FHWA, NHTSA
indicated that a combination amber turn signal and tail lamp is
implicitly prohibited by FMVSS No. 108. NHTSA stated:

When combined with an amber turn signal lamp, the intensity of
an amber tail lamp might mask the turn signal operation. Because
motorists are not used to seeing steady burning amber lamps on the
rear of vehicles, amber taillamps could lead to momentary confusion
of a driver following the trailer when the stop lamps are activated,
thereby impairing the effectiveness of the stop signal. The presence
of simultaneously burning amber and red taillamps could also create
some confusion of a following driver approaching the trailer from
around a corner to its rear. Thus we have concluded that a

[[Page 48013]]

combination amber turn signal and taillamp is implicitly prohibited
by Standard No. 108.

FMCSA agrees that motorists are not use to seeing amber lamps used in
conjunction with red lamps to signal that the vehicle is stopping and
believes the FMCSRs should be amended explicitly to prohibit the use of
amber tail lamps.
To ensure the prohibition does not conflict with FMVSS No. 108,
FMCSA reviewed NHTSA requirements. Section S5.1.3 of FMVSS No. 108
prohibits the installation of supplementary lighting equipment that
``impairs the effectiveness of lighting equipment required by this
standard.'' Although the determination of impairment is initially that
of the vehicle's manufacturer in certifying that the vehicle meets all
applicable FMVSSs, NHTSA may review that determination and, if clearly
erroneous, inform the manufacturer of its views.
Because Sec. 393.11 cross-references FMVSS No. 108, FMCSA's
regulatory guidance on the use of amber stop lamps and tail lamps is
generally contingent upon a NHTSA determination as to whether or not
the lamp impairs the effectiveness of other rear lamps. While
certification by the vehicle manufacturer and subsequent review by
NHTSA address the vehicle manufacturer's role in the safe operation of
the CMV, a less complicated approach is needed to ensure that the
FMCSRs are easy to understand, use, and enforce.
Explicit guidance is provided to ensure that once a vehicle
manufacturer certifies that a vehicle meets all applicable FMVSSs, the
motor carrier does not modify it in a manner inconsistent with FMVSS
No. 108. FMCSA is not aware of any vehicle manufacturers that use amber
stop lamps or tail lamps as standard equipment. Consequently, the
restriction would: (1) Discourage motor carriers from asking vehicle
manufacturers to install amber tail lamps and/or stop lamps on vehicles
as optional equipment, and (2) prohibit the motor carrier from
installing or using such devices on its commercial motor vehicles.
With regard to omissions in Table 1 in Sec. 393.11, FMCSA amends
footnotes 4 through 10 to address inconsistencies with other sections
of subpart B to part 393. In addition, the agency is correcting the
listing for clearance lamps and reflex reflectors and to include metric
units in describing the location of the required lamps and reflectors.
The current listing for clearance lamps omits reference to footnote
8 concerning pole trailers and does not include reference to the
provision in FMVSS No. 108 (S5.1.1.9) for clearance lamps on boat
trailers. Under FMVSS No. 108, a boat trailer with an overall width of
2,032 mm (80 inches) or more is not required to be equipped with both
front and rear clearance lamps provided an amber (to the front) and red
(to the rear) clearance lamp is located at or near the midpoint on each
side to indicate the extreme width of the trailer. This provision for
clearance lamps on boat trailers is covered under a new footnote 17.
The listings for reflex reflectors (front side) and side marker
lamps (front) are revised to address an inconsistency between Sec.
393.11 and FMVSS No. 108 (S5.1.1.15). Under FMVSS No. 108, a trailer
that is less than 1,829 mm (6 feet) in length (including the trailer
tongue) need not be equipped with front side marker lamps and front
side reflex reflectors. This exception is covered under a new footnote 16.
FMCSA removes the last sentence in footnote 4, which requires that
the rear side marker lamps be visible in the rearview mirror. This
requirement is impractical and is inconsistent with FMVSS No. 108.
Section 571.108 (S5.1.1.8) incorporates by reference the Society of
Automotive Engineers recommended practice Clearance, Side Marker, and
Identification Lamps, (SAE J592e, July 1972) which provides photometric
standards. These standards cover visibility angles of 45 degrees left
to 45 degrees right and 10 degrees up to 10 degrees down. In order for
the rear side marker lamps to be visible in the rearview mirrors, the
left to right angles would each have to be approximately 85 degrees.
Because side marker lamps which meet the minimum standards contained in
SAE J592e generally are not visible in the rearview mirror, the agency
amends footnote 4.
FMCSA makes editorial changes to footnotes 5 through 8 to improve
the manner in which the requirements are presented. For instance, in
footnote 5, the change makes it clear that converter dollies are only
required to have one stop lamp and one tail lamp. The current wording,
when combined with the legend at the end of Sec. 393.11, could be
construed as requiring two stop lamps and two tail lamps.
Amendments to footnotes 9 and 10 remove the requirements that
projecting loads be equipped with lamps and reflectors during daylight
hours. There is no apparent safety benefit for requiring lamps and
reflectors on projecting loads during times when lamps are not required
to be used.
Footnote 15 is revised to incorporate language consistent with
certain FMVSS No. 108 options--covered under S5.3.1.1.1, S5.3.1.4,
S5.3.1.6--on the locations for clearance lamps.
Section 393.17--Lamps and Reflectors, Driveaway-Towaway Operations
FMCSA amends the wording of the diagrams which illustrate the
requirements of Sec. 393.17. The diagrams incorrectly reference
Sec. Sec. 393.25(e) and 393.26(d); therefore, the sections are amended
to reference Sec. 393.11, which covers the color of exterior lamps and
reflective devices.
Section 393.19--Requirements for Turn Signaling Systems
FMCSA revises Sec. 393.19 to make it more consistent with FMVSS
No. 108 (S5.5.5). Paragraph S5.5.5 provides a concise standard that
vehicle manufacturers must meet. To ensure consistency between FMVSS
No. 108 and the FMCSRs, FMCSA adopts the NHTSA standard.
Section 393.20--Clearance Lamps to Indicate Extreme Width and Height
FMCSA removes Sec. 393.20 because the requirements for the
location and color of clearance lamps are provided in Table 1 of Sec.
393.11. The exceptions concerning the mounting of clearance lamps
currently contained in Sec. 393.20 is included under footnote 15 to
Table 1. Illustrations comparable to those provided in Sec. 393.20 are
already contained in Sec. 393.11.
Section 393.23--Lighting Devices to be Electric
FMCSA amends Sec. 393.23 to incorporate terminology which is more
consistent with current industry standards and practices. With the
exception of temporary lamps used on projecting loads, lamps are
required to be powered through the electrical system of the commercial
motor vehicle. The title of Sec. 393.23 is revised to read ``Power
supply for lamps'' and the reference to red liquid-burning lanterns is
removed as obsolete.
Section 393.24--Requirements for Headlamps and Auxiliary Road Lighting
Lamps
FMCSA amends Sec. 393.24 to provide a more straightforward
presentation of the requirements for the mounting of headlamps and
auxiliary lamps, and to incorporate by reference SAE standards
applicable to these lamps. Currently, Sec. 393.24 allows auxiliary and
fog lamps to be used provided they meet ``the appropriate SAE standard
for such lamps.'' FMCSA incorporates by

[[Page 48014]]

reference SAE standards J581 Auxiliary Upper Beam Lamps, July 2004, and
J583 Front Fog Lamps, August 2004, for the purpose of establishing more
specific performance requirements for such lamps. While auxiliary
driving lamps and fog lamps are not required to be used, performance
standards are being specified to ensure that the use of such devices
does not decrease safety.
A new paragraph is being added to address marking of headlamps.
Paragraph S7.2 of FMVSS No. 108 requires the lens of each headlamp and
beam contributor manufactured on or after December 1, 1989, to be
marked. FMCSA amends the FMCSRs to include this requirement under Sec.
393.24 to ensure that commercial motor vehicles are equipped with
original or replacement headlamps which meet the requirements of FMVSS
No. 108.
Paragraph (d) of Sec. 393.24, Aiming and intensity, is being
revised to reference FMVSS No. 108, and SAE standards J581 and J583.
One of the SAE standards currently referenced in Sec. 393.24(d)--
Electric Headlamps for Motor Vehicles--was canceled by the SAE. The
other SAE standard, J579 Sealed Beam Headlamp Units for Motor Vehicles,
is not necessary given the cross-reference to FMVSS No. 108 and the
incorporation by reference of SAE J581 and J583.
Section 393.25--Requirements for Lamps Other Than Headlamps
To improve the clarity with which the requirements are presented,
FMCSA revises Sec. 393.25 in its entirety. Section 393.25(a) provides
a concise description of the mounting requirements for lamps. Paragraph
(b), entitled ``Visibility,'' provides technically sound performance
standards for all required lamps. Currently, Sec. 393.25(b) requires
lamps to be mounted such that they are capable of being seen at
distances up to 152.4 meters (500 feet) under clear atmospheric
conditions during the period when lamps must be used as provided by
Sec. 392.30. FMCSA determined that Sec. 392.30 duplicated State and
local regulations and removed that requirement on November 23, 1994 (59
FR 60319). Also, FMCSA believes the performance criteria for lamps are
effectively addressed by Sec. 393.11 which cross-references FMVSS No.
108. Lamps must, at a minimum, meet the requirements of FMVSS No. 108
in effect on the date of manufacture of the vehicle. FMVSS No. 108
specifies the minimum and maximum photometric output values for
required lamps. Vehicles not subject to FMVSS No. 108 on the date of
manufacture are required to meet the visibility requirements specified
in the SAE standards for incorporation by reference under Sec. 393.25(c).
FMCSA deletes Sec. 393.25(d), entitled ``Certification and
markings,'' to make the FMCSRs consistent with FMVSS No. 108. With the
exception of headlamps and beam contributors, FMVSS No. 108 does not
require lamps to be marked. Manufacturers are responsible for ensuring
that their products meet the applicable requirements of FMVSS No. 108,
but the lamps do not need to be marked by the manufacturer to indicate
that the device meets the standards. In this case, Sec. 393.25(d) sets
in-service requirements for lamps which are more stringent than the
manufacturing standards set by the NHTSA. The removal of Sec.
393.25(d) corrects this inconsistency.
FMCSA amends Sec. 393.25(e), entitled ``Lighting devices to be
steady-burning,'' and Sec. 393.25(f), entitled ``Stop lamp
operation,'' to provide more concise statements of the requirements of
each. The FMCSA is allowing exceptions for the use of amber warning
lamps which meet SAE J595, Directional Flashing Optical Warning Devices
for Authorized Emergency, Maintenance, and Service Vehicles, January
2005, SAE J845, Optical Warning Devices for Authorized Emergency,
Maintenance, and Service Vehicles, May 1997, or SAE J1318 Gaseous
Discharge Warning Lamp for Authorized Emergency, Maintenance, and
Service Vehicles, May 1998. All of these SAE recommended practices are
incorporated by reference. Although the notice of proposed rulemaking
preceding this final rule would have prohibited the use of certain
Class 1 warning devices, FMCSA no longer believes such a prohibition is
necessary. Several commenters indicated amber colored Class 1 warning
devices are commonly used on certain commercial motor vehicles and
there has been no adverse impact on safety. Adding these devices to the
list of exceptions prevents confusion about the applicability of Sec.
393.25(e).
FMCSA revises Sec. 393.25(f) to eliminate a regulatory
inconsistency between Sec. Sec. 393.25(f) and 393.49 and to simplify
the wording of the requirements. Currently, Sec. 393.25(f) states that
stop lamps on a towing vehicle need not be actuated when service brakes
are applied to the towed vehicle(s) only. This provision is
inconsistent with Sec. 393.49, entitled ``Single valve to operate all
brakes.'' When a combination vehicle includes a trailer that is
required to be equipped with brakes, the braking system must be
arranged so that a single valve controls the brakes on the towing unit
and the towed unit. Because the FMCSRs do not allow the towing unit to
operate without service brakes, and a single valve is required to
operate all the brakes on the combination, the current wording of Sec.
393.25(f) is inconsistent with Sec. 393.49. The revision to Sec.
393.25(f) includes language from FMVSS No. 108, S5.5.4, concerning stop
lamp operation, to ensure consistency between the FMCSRs and the FMVSSs.
Section 393.26--Requirements for Reflectors
Consistent with the amendments to Sec. 393.25, FMCSA is revising
Sec. 393.26 in its entirety. FMCSA amends Sec. 393.26(a) concerning
the mounting of reflectors, to provide guidelines comparable to those
for Sec. 393.25(a). Paragraph (b) is revised to include a requirement
that reflex reflectors on projecting loads, vehicles transported in
driveaway-towaway operations, converter dollies, and pole trailers meet
SAE J594--Reflex Reflectors, December 2003. The SAE recommended
practice is incorporated by reference.
The current requirement for certification and marking under Sec.
393.26(c) is being removed to make the FMCSRs consistent with FMVSS No.
108. FMVSS No. 108 does not require that reflectors be marked by the
manufacturer to indicate that the device meets the standards. Paragraph
(c) would then be used to incorporate American Society for Testing and
Materials (ASTM) D4956-04, Standard Specification for Retroreflective
Sheeting for Traffic Control, as the minimum standard for reflective
tape used in lieu of reflex reflectors. Retroreflective sheeting that
conforms to the ASTM standard would generally meet the requirements of
FMVSS No. 108, S5.1.1.4, concerning the use of reflective tape in lieu
of reflex reflectors. The performance of the reflective sheeting as
installed on the vehicle must meet the visibility requirements under
SAE J594, Reflex Reflectors, December 2003.
Paragraph (d) is being revised to more clearly state that
reflective surfaces or materials other than those required by Sec.
393.11 may be used in addition to, but not in lieu of, the required
reflective devices.
Sections 393.27, 393.28, 393.29, 393.31, 393.32, 393.33--Regulations on
Electrical Wiring
FMCSA incorporates by reference in Sec. 393.28, SAE J1292--
Automobile, Truck, Truck-Tractor, Trailer, and Motor Coach Wiring,
October 1981, which covers basic aspects of performance, operating
integrity, and service. Section

[[Page 48015]]

393.28 is being renamed ``Wiring systems.'' The guidelines contained in
J1292 effectively cover the requirements currently addressed by Sec.
393.27, Wiring specifications; Sec. 393.28, Wiring to be protected;
Sec. 393.29, Grounds; Sec. 393.31, Overload protective devices; Sec.
393.32, Detachable electrical connections; and Sec. 393.33, Wiring,
installation. Among the specific topics addressed by the SAE standard
are insulated cables; conductor termination; conductor splicing;
conductor grouping; wire assembly construction; wire assembly
installation and protection; and wiring overload protective devices.
The SAE standard for incorporation provides a concise presentation of
those aspects of commercial vehicle electrical systems that should be
addressed by the FMCSRs. Sections 393.27, 393.29, 393.31, 393.32 and
393.33 are being removed.
The incorporation by reference removes certain design restrictive
language from Sec. 393.28(a)(5) concerning terminals or splices above
the fuel tank. FHWA received petitions from the Ford Motor Company,
Freightliner Corporation, and the Motor Vehicle Manufacturers
Association (now the American Motor Vehicle Manufacturers Association)
requesting an amendment to Sec. 393.28(a)(5), which was adopted in the
December 7, 1988, final rule (53 FR 49380). The petitions are available
for review in the docket. Each of the petitions pointed out that use of
the word ``terminal'' combined with ``above'' created ambiguity with
respect to the proximity of electrical wiring to the fuel tanks.
Electrical terminals performing various functions, from battery
terminals (Ford Motor Co.) to relays and switches (Freightliner
Corporation), are mounted above the fuel tanks. In some instances these
switches or relays with terminals are mounted 203 mm (8 inches) or more
above the fuel tank or on the frame rail (in the case of Freightliner
and Daimler-Benz power units). In the case of Ford power units, the
fuel tank is specifically designed for battery installation.
The notice of proposed rulemaking that preceded the final rule
would have prohibited wiring from being adjacent to any part of the
fuel system (52 FR 5892, February 26, 1987). The wording in the final
rule was less restrictive than the proposed language and focused
specifically on terminals and splices. FMCSA agrees with the
petitioners, however, that Sec. 393.28(a)(5) is still unnecessarily
restrictive. FMCSA's decision to incorporate by reference criteria that
effectively and safely address the issue of wiring around the fuel
system of commercial motor vehicles resolves the petitioners' concerns.
FMCSA includes an exception to the incorporation by reference for
jumper cable plugs and receptacles, and circuit protection requirements
for trailers. Jumper plugs and receptacles need not conform to SAE J560
Primary and Auxiliary Seven Conductor Electrical Connector for Truck-
Trailer Jumper Cable, which provides the minimum requirements for
primary and auxiliary jumper cable plugs and receptacles for the truck-
trailer and converter dolly jumper cable systems. TTMA indicated in its
comments most trailers are equipped with an SAE J560 receptacle, but
they may also have a modified International Standards Organization
(ISO) 3731 receptacle, while others may have a 13-conductor Cole-Hersee
receptacle. FMCSA agrees with TTMA and believes safety would not be
compromised by allowing flexibility.

Subpart C--Brakes

Section 393.40--Required Brake Systems
FMCSA revises Sec. 393.40 in its entirety to present more clearly
the requirements contained therein. Generally, vehicles that have been
maintained to continue compliance which meet the manufacturing
standards applicable at the time of the vehicle is built, will not be
affected by the revisions. Hydraulic braked and air braked vehicles are
required to meet the requirements of FMVSS Nos. 105 and 121,
respectively, in effect at the time of manufacture. The service,
parking, and emergency brake requirements for vehicles which were not
subject to either of the FMVSS brake regulations is provided by
references to other applicable sections in subpart C and by the
requirements currently found under Sec. 393.40(b)(2) and (c).
With regard to FMVSS No. 105, FMCSA notes that between September 1,
1975, and October 12, 1976, the standard was applicable to trucks and
buses. However, from October 12, 1976, to September 1, 1983, it covered
only passenger cars and school buses. From 1983 to the present, the
standard has applied to trucks and buses. For the purposes of Sec.
393.40, FMCSA will use September 2, 1983, as the date for determining
which hydraulic-braked vehicles must be maintained to meet certain
requirements under FMVSS No. 105.
There could be some benefit in requiring vehicles manufactured
between September 1975 and October 1976 to meet the requirements of
FMVSS No. 105 in effect on the date of manufacture. However, the number
of these older vehicles still in operation is relatively small, and the
brake requirements under part 393 to which these vehicles would
continue to be subject should ensure safety of operation.
Section 393.41--Parking Brake System
The December 7, 1988, final rule on part 393 was intended to make
the parking brake requirements of the FMCSRs consistent with the
parking brake requirements of FMVSS Nos. 105 and 121. FMCSA has since
determined that additional changes are necessary. The current language
only covers vehicles with air brakes manufactured on or after March 7,
1990, which are subject to FMVSS No. 121. The wording implies that all
non-air braked vehicles, irrespective of the date of manufacture, and
air braked motor vehicles manufactured prior to that date are not
required to be equipped with parking brakes.
Prior to the 1988 amendment, Sec. 393.41 required that every
singly driven motor vehicle and every combination of motor vehicles
shall at all times be equipped with a parking brake system adequate to
hold the vehicle or combination on any grade on which it is operated
under any condition of loading on a surface free from ice or snow.
FMCSA considers the parking brake requirements in effect prior to the
1988 amendment to provide a more straightforward standard that is
easier for the industry and State officials to understand.
FMCSA revises Sec. 393.41 to state clearly that every self-
propelled commercial motor vehicle (i.e., trucks, truck-tractors and
buses) and every combination of commercial motor vehicles must be
equipped with a parking brake system adequate to hold the vehicle or
combination on any grade on which it is to be parked and under any
condition of loading, on a surface free from ice or snow. Commercial
motor vehicles which were subject to the parking brake requirements of
FMVSS Nos. 105 or 121 at the time of manufacture are required to
maintain the parking brake systems to meet those standards. Motor
vehicles which were not subject to either of the FMVSS parking brake
requirements must meet the requirements currently found at Sec.
393.41(b) and (c).
The revisions to Sec. 393.41 also address a petition for
rulemaking from International Transquip Industries, Incorporated (ITI)
asking FMCSA to clarify the applicable requirements for air-applied,
mechanically-held, parking brakes. The petition is available for review
in the docket. The ITI

[[Page 48016]]

manufactures an air brake system which includes an air-applied,
mechanically-held parking brake. The parking brake application is
initiated by exhausting air off the supply line. When the control valve
senses the supply line pressure drop, it ports air from either the
primary or secondary reservoirs at a controlled pressure to the brake
chambers resulting in an application of the brakes. The same supply
line pressure signal activates a synchronizing device which engages the
mechanical pistons immediately after the brakes have been applied.
Section 393.41(b) requires that the parking brake be capable of
being applied at all times by either the driver's muscular effort, or
by spring action, or by other energy. In the case of ``other energy,''
the accumulation of such energy must be ``isolated from any common
source and used exclusively for the operation of the parking brake.''
This wording has been in effect since 1962 and could be construed as
requiring a separate reservoir for air-applied, mechanically-held
parking brakes. Such a requirement is inconsistent with FMVSS No. 121.
On August 9, 1979, NHTSA amended FMVSS No. 121 to allow the
application of the parking brakes by means of service brake air if: (1)
The application could be made when a failure exists in the service
brake system, and (2) the parking brake is held in the applied position
by mechanical means (44 FR 46850). Prior to this amendment, an air-
applied, mechanically-held parking brake was required to be applied by
a separate reservoir. The revision of Sec. 393.41(b) includes a cross-
reference to the parking brake requirements of FMVSS No. 121, thus
eliminating any inconsistencies.
For air braked vehicles which were not subject to FMVSS No. 121 at
the time of manufacture, Sec. 393.41 would continue to allow the use
of air-applied, mechanically-held parking brake systems applied by a
separate reservoir. The motor carrier would have the option of
modifying the brake system to meet FMVSS No. 121. Air-applied,
mechanically-held parking brakes which are designed to operate without
a separate reservoir could be used if the conditions specified in FMVSS
No. 121 are met.
Section 393.42--Brakes Required on All Wheels
The agency is revising Sec. 393.42(b)(3) to clarify the exceptions
for lightweight trailers and to address brake requirements on
housemoving dollies, three-axle dollies steered by a co-driver, and
similar dollies and trailers used for transporting extremely large and
heavy loads at low speeds.
As part of the January 27, 1987, final rule on front wheel brakes,
FMCSA amended the exemption for brakes on lightweight trailers (52 FR
2801). Prior to the amendment, full trailers, semi-trailers, or pole
trailers with a gross weight of less than 1,360 kg (3,000 pounds) were
not required to have brakes provided the weight of the trailer did not
exceed 40 percent of the weight of the towing unit. The 1987 amendment
replaced the term ``gross weight'' with ``GVWR'' or gross vehicle
weight rating.
While the change to GVWR has certain benefits in terms of applying
the regulation to situations in which it is not convenient to weigh the
trailer, the amendment did not adequately address concerns about
stability and control during braking for trailers that have a GVWR
greater than 1,361 kg (3,000 pounds), but an actual or gross weight
less than 1,361 kg when lightly loaded. Under certain circumstances,
trailers of this weight range may be overbraked resulting in wheel
lockup or skidding when the trailer is lightly loaded. FMCSA believes
Sec. 393.42 should be amended to make reference to the gross weight.
Trailers covered under the current reference to GVWR are covered under
the revised exemption provided the vehicle is not loaded beyond the
manufacturer's weight rating. Trailers with a GVWR in excess of 1,361
kg (3,000 pounds) would only be covered by the exemption on those
occasions when the gross weight of the trailer is 1,361 kg (3,000
pounds) or less. The language would help to provide a performance-based
criterion that is easier to understand and enforce.
Although the exemption concerning lightweight trailers never
specifically addressed converter dollies, the issue of overbraking on
unladen converter dollies has been the subject of several requests for
interpretation of Sec. 393.42(b). Converter dollies are generally
designed to carry loads of approximately 9,072 kg (20,000 pounds) with
a brake system sized for the fully loaded condition. While the GVWR is
greater than 1,360 kg (3,000 pounds) the unladen weight is usually
1,360 kg or less. When towed behind another motor vehicle, the unladen
converter dolly is overbraked, with the application of the service
brakes causing wheel lock-up or skidding.
In 1990, NHTSA's Vehicle Research and Test Center (VRTC) conducted
tests to evaluate the braking and stability of a bobtail truck tractor
towing an unladen converter dolly. Both the truck tractor and the
converter dolly were equipped with ABS that could be deactivated. The
truck tractor was also equipped with an automatic front-axle limiting
valve (ALV) and a bobtail proportioning valve (BPV) that could each be
deactivated.
The tests included 97 km/hour (60 mph) straight-lane braking, 48
km/hour (30 mph) braking in a 152.4 meters (500 ft) radius curve, and
56 km/hour (35 mph) straight-lane braking. The 97 km/hour straight-line
braking tests were performed on dry concrete (high coefficient of
friction surface). The braking-in-a-curve tests were performed on wet
Jennite (low coefficient of friction surface). The 56 km/hour straight-
lane braking was performed on wet polished concrete. The tests used
``driver best effort'' for the cases in which the ABS was turned off,
and full-treadle brake applications with the ABS turned on.
When the brakes on the converter dolly were not connected, stopping
distances were increased by 12 to 30 percent over those for the bobtail
tractor without the converter dolly. Also, the absence of braking on
the converter dolly made locking the drive axles of the tractor easier
which caused the combination to jackknife. The absence of braking on
the dolly did, however, prevent locking the wheels and subsequent
swing-out of the dolly.
When the brakes on the converter dolly were connected and the
tractor did not have a BPV system, stopping distances on the two wet
surfaces were 10 to 25 percent shorter than those with the bobtail
tractor alone. On the dry surface the stopping distances were slightly
longer with the dolly brakes operational. When the tractor was equipped
with a BPV system and the dolly brakes were connected, stopping
distances were longer on all of the test surfaces and in one case by as
much as 60 percent.
There were no stopping distance decreases observed for the tests
performed on the dry concrete when the converter dolly brakes were
connected. However, the increases were significantly less than those
observed when the converter dolly brakes were disconnected.
While having operable brakes on the unladen converter dolly
decreased stopping distances in certain cases, two disadvantages were
observed. If the tractor is equipped with a BPV, hooking up the supply
(emergency) line to release the parking brakes on the dolly will
deactivate the BPV and activate the ALV. This is true even if the
control (service) line is not hooked up to the dolly. This practice
significantly degrades braking performance,

[[Page 48017]]

increasing both the stopping distance and the chance of a jackknife of
the combination vehicle. The other disadvantage is that the converter
dolly can swing out if the wheels lock up.
Stability and control during braking is an important consideration
in determining braking requirements for commercial motor vehicles.
While stopping distances for a bobtail tractor towing an unladen
converter dolly could be improved in some situations by requiring
operable dolly brakes, they could be significantly degraded in others.
When consideration is given to the possibility of the converter dolly
swinging out as a result of wheel lock up, the FMCSA believes the
FMCSRs should be amended to include an exception to the requirement for
operable brakes on unladen converter dollies.
Although regulatory guidance published by the FMCSA on November 17,
1993 (58 FR 60734) stated that Sec. 393.42(b)(3) is applicable to
unladen converter dollies, FMCSA is creating an exception for converter
dollies under Sec. 393.48, Brakes to be operative. Converter dollies
are always equipped with brakes. Nevertheless, the air lines for the
service brakes are sometimes disconnected from the towing vehicle when
the converter dolly is unladen. Therefore, an exception to Sec. 393.42
(the requirement that the converter dolly be equipped with brakes) is
not necessary. FMCSA is addressing the problem by amending Sec. 393.48
to provide an exception to the requirement that the brakes be operable
when the converter dolly is unladen.
FMCSA notes that with NHTSA's March 10, 1995 (60 FR 13216) final
rule on antilock braking systems (ABS), the long-term need for this
exception for unladen converter dollies will diminish. An ABS-equipped
converter dolly will not have the stability and control problems
observed with unladen converter dollies that are not equipped with ABS.
Therefore, converter dollies manufactured on or after March 1, 1998,
the effective date of the NHTSA requirement for ABS on converter
dollies, are not covered by the exception.
On the subject of housemoving dollies and similar vehicles designed
to transport extremely large and/or heavy loads, FMCSA is providing an
exemption to the requirement for brakes on all wheels based on the
specialized circumstances under which these motor vehicles are used on
public roads. Housemoving dollies are only used on public roads when
transporting houses. Semitrailers are used to transport the dollies
between jobs. When the dollies are used to transport houses, the
average speed is less than 32 km/hour (20 mph). Also, escort vehicles
are generally used when the houses are being moved.
Similarly, specialized trailers and dollies used to transport
industrial furnaces, reactors and other heavy cargo are operated at
speeds less than 32 km/hour (20 mph) and have escort vehicles. FMCSA
does not believe that safety is compromised by providing an exception
to the requirement for brakes on all wheels, provided the brakes on the
towing unit are capable of stopping the combination within 12.2 meters
(40 feet) from the speed at which the vehicle is being operated or 32
km/hour (20 mph), whichever is less.
The exemption to the requirement for brakes on all wheels also
covers the steering axles of three-axle dollies which are steered by a
co-driver (tillerman) at the rear. These dollies are often used to
transport concrete or steel beams used for bridges or other structures.
The loads are often in excess of 30.5 meters (100 feet) in length. The
front of the load is secured to the power unit with the rear of the
load secured to the three-axle steerable dolly. A co-driver, seated in
the dolly, operates the steering controls to help maneuver the
combination vehicle. Although the dolly is equipped with brakes via air
lines from the towing unit, the steering axle is typically overbraked
making it difficult for the co-driver to steer the dolly. When the
dolly is loaded, the steering axle weight rarely exceeds 3,402 kg
(7,500 pounds).
FMCSA does not believe that an exemption to the requirement for
steering axle brakes on these vehicles would degrade safety. The
vehicles transport unusually long loads, often require special permits,
and have to operate at reduced speeds. Therefore, the agency is
exempting the steering axles of such vehicles from the requirement of
Sec. 393.42(a) that all wheels be equipped with brakes provided the
combination of vehicles can meet the stopping distance requirements
under Sec. 393.52.
Section 393.43--Breakaway and Emergency Braking
FMCSA revises Sec. 393.43(a) to include better guidance on the
performance requirements for towing vehicle brake protection systems.
An explicit requirement that the tractor protection valve or similar
device operate when the air pressure on the towing vehicle is between
138 kilopascals (kPa) and 310 kPa (20 pounds per square inch (psi) and
45 psi) is added. This criterion has been used for many years during
roadside inspections and its inclusion in Sec. 393.43(a) should not
create a problem for motor carriers.
FMCSA revises Sec. 393.43(b) to codify its interpretation of the
number of trailer brakes required to apply automatically upon breakaway
from the towing vehicle. On November 17, 1993, the FMCSA published
regulatory guidance which indicated that all brakes must be applied
upon breakaway (58 FR 60734). This is consistent with the FMCSA's
November 23, 1977, interpretation (42 FR 60078). Because FMVSS No. 121
does not specify the number of trailer brakes that must apply
automatically, it is possible that some trailers may be able to meet
those performance requirements without having all the brakes apply upon
breakaway. To ensure the enforceability of the breakaway requirements
and consistency between Sec. 393.43 and the FMVSSs, FMCSA amends the
regulation to specify that all brakes must apply automatically, but the
requirement is not applicable to trailers with more than two axles.
Trailers with more than two axles typically would not have brakes that
apply automatically upon breakaway, on each axle.
Sections 393.45 and 393.46--Brake Tubing and Hose
FMCSA revises Sec. 393.45 to address all aspects of brake tubing
and hoses, including connections, and to remove Sec. 393.46.
Currently, Sec. 393.45 requires that brake tubing and brake hose be
designed and constructed in a manner that ensures proper, adequate, and
continued functioning of the tubing or hose. The tubing or hose must be
long and flexible enough to accommodate without damage all normal
motions of the parts to which they are attached; be suitably secured
against chaffing, kinking, or other mechanical damage; and be installed
in a manner that ensures proper continued functioning and prevents
contact with the vehicle's exhaust system. Section 393.45 cross-
references FMVSS No. 106 as well as several SAE standards.
FMCSA retains most of the current language regarding the
installation of the brake hoses and the cross-reference to FMVSS No.
106. The current language regarding the design, material, and
construction (Sec. Sec. 393.45(a) and (b)) is removed because the
cross-reference to FMVSS No. 106 addresses manufacturing aspects of
brake tubing and hoses.
Also, FMCSA eliminates all references to SAE standards on brake
hoses, including SAE J844--Nonmetallic Air Brake System Tubing. Based
upon its review of NHTSA's December 20, 2004, final rule

[[Page 48018]]

concerning FMVSS No. 106, FMCSA believes there is no readily apparent
benefit to incorporating by reference any of the SAE standards. Because
brake hose manufacturers are required to meet all applicable
requirements under FMVSS No. 106, the SAE references are unnecessary.
FMCSA removes Sec. 393.45(d) because it does not impose any
specific requirements on motor carriers. As written, the paragraph
serves as a suggestion or recommendation on the use of metallic and
nonmetallic brake tubing. Also, given the performance-based
requirements for brake hose/tubing installation being adopted through
this final rule, the current language in Sec. 393.45(d) is no longer
necessary.
The changes to Sec. 393.45 address a petition for rulemaking from
Imperial Eastman, a brake tubing/hose manufacturer. The petition is
available for review in the docket. Imperial Eastman believes that
certain coiled nonmetallic air brake tubing which did not meet FMVSS
No. 106 was introduced into the market place as a direct result of
Sec. 393.45. Imperial Eastman believes that prior to the December 7,
1988, final rule, Sec. 393.45 was clear and that the 1988 revision has
been interpreted by some as not applying the SAE J844 requirements to
nonmetallic air brake tubing. FMCSA believes the cross-reference to
FMVSS No. 106 makes it clear that any brake hose, irrespective of the
material from which it is manufactured, that meets the requirements of
FMVSS No. 106 would satisfy Sec. 393.45.
On the subject of brake tubing and hose connections, the revised
wording of Sec. 393.45 requires that all assemblies and end fittings
for air, vacuum, or hydraulic braking systems be installed so as to
ensure an attachment free of leaks, constrictions or other conditions
which would adversely affect the performance of the brake system. Brake
tubing and hose assemblies and end fittings are required to meet all
applicable requirements under FMVSS No. 106, as is currently the case.
These requirements, currently covered under Sec. 393.46, are covered
under Sec. 393.45(e). Because the language for Sec. 393.45 includes
requirements concerning installation, connections and attachments,
Sec. 393.46 is removed.
Section 393.47--Brake Lining
Section 393.47 is revised to cover brake chambers, slack adjusters,
linings and pads, drums and rotors. Brake components are required to be
constructed, installed, and maintained to prevent excessive fading and
grabbing. The means of attachment and physical characteristics must
provide for safe and reliable stopping of the commercial motor vehicle.
To make the requirements of part 393 consistent with the periodic
inspection requirements under appendix G to subchapter B, Sec. 393.47
is amended to require that the service brake chambers and spring brake
chambers on each end of an axle be the same size. The effective length
of the slack adjuster on each end of an axle is required to be the
same. In addition, minimum requirements on the thickness of linings or
pads are specified.
With regard to linings and pads, the criteria differ from appendix
G. Currently, appendix G does not adequately address the issue of brake
lining thickness on the steering axles of certain vehicles (typically
those with a GVWR between 4,536 and 14,969 kg (10,001 and 33,000
pounds)). This issue was brought to the attention of the FMCSA by the
American Trucking Associations (ATA). The ATA discussed front brake
lining thickness in a petition for reconsideration of the final rule on
periodic inspection. The petition is available for review in the
docket. In its petition, the ATA stated:
There are two configurations of brake lining used on steering
axle brakes: blocks (sometimes called pads) and strips. Block lining
is installed in four segments on the two shoes of each front brake.
Such lining is typically well over \1/4\ inch thick when new and the
\1/4\ inch annual inspection criteria is correct for it. Strip
lining, as the name implies, consists of a continuous band of lining
installed in two segments, one on each shoe of an individual front
brake. Certain types of strip lining are only slightly over \1/4\
inch thick when new. Therefore a \1/4\ inch annual inspection
criteria is inappropriate.

The roadside inspection guidelines used by Federal and State
inspectors have the following criteria to determine if the linings or
pads of the steering axle of any power unit are worn to the point of
creating an imminent hazard:

Lining with a thickness less than \3/16\ inch for a shoe with a
continuous strip of lining or \1/4\ inch for a shoe with two pads
for drum brakes or to wear indicator if lining is so marked, or less
than \1/8\ inch for air disc brakes, and \1/16\ inch or less for
hydraulic disc, drum and electric brakes.

FMCSA believes these guidelines should be added to Sec. 393.47 to
help motor carriers identify steering axle brake linings and pads that
are excessively worn. FMCSA will consider a separate rulemaking to
amend appendix G to subchapter B, concerning the periodic inspection
critieria. To address non-steering axle brake lining/pads, FMCSA
incorporates into Sec. 393.47 the same criteria currently found in
appendix G.
Brake actuator readjustment limits are also being specified under
Sec. 393.47. The pushrod travel for clamp and roto-chamber type
actuators is required to be less than 80 percent of the rated strokes
listed in SAE J1817--Long Stroke Air Brake Actuator Marking, July 2001,
or 80 percent of the rated stroke marked on the brake chamber by the
chamber manufacturer, or the readjustment limit marked on the brake
chamber by the chamber manufacturer. The pushrod travel for Type 16 and
20 long stroke clamp type brake actuators (which are not covered under
SAE J1817 but for which there are manufacturers' recommendations) is
required to be less than 51 mm (2 inches), or 80 percent of the rated
stroke marked on the brake chamber by the chamber manufacturer, or the
readjustment limit marked on the brake chamber by the chamber
manufacturer. For wedge brakes, the movement of the scribe mark on the
lining could not exceed 1.6 mm (\1/16\ inch). With regard to brake
drums and rotors, the thickness of the drums or rotors must meet the
limits established by the brake drum or rotor manufacturer.
Section 393.48--Brakes To Be Operative
FMCSA revises Sec. 393.48(a) and (b) to make the requirements
easier to understand. The revisions provide a more concise presentation
of the requirements.
With regard to paragraph (c), the FMCSA explicitly addresses the
issue of unladen converter dollies and lift axles. Braking on unladen
converter dollies is covered extensively in discussion of the changes
to Sec. 393.42. Unladen converter dollies with a gross weight of 1,361
kg (3,000 lbs) or less would not be required to have operable brakes.
Brakes on lift axles would not be required to be capable of operation
while the lift axle is raised. However, brakes on lift axles must be
operable whenever the lift axle is lowered and the tires contact the
roadway. Therefore, if an enforcement official instructs a driver to
lower the lift axle to the ground during an inspection, the driver is
required to demonstrate that the brakes on that axle are operable. The
revision would essentially codify regulatory guidance on these issues.
In addition, the issue of housemoving dollies, three-axle steerable
dollies, and similar motor vehicles used to transport extremely heavy
loads is addressed to ensure consistency between the revisions to Sec.
393.42 and Sec. 393.48.
Section 393.50--Reservoirs Required
Section 393.50 is revised to provide a simpler and more concise
presentation

[[Page 48019]]

of the reservoir requirements and to cross-reference FMVSS No. 121.
Each air braked truck, truck-tractor, and bus manufactured on or after
March 1, 1975, would at a minimum be required to meet FMVSS No. 121,
S5.1.2, in effect on the date of manufacture. Trailers manufactured on
or after January 1, 1975, must meet the requirements of FMVSS No. 121,
S5.2.1, in effect on the date of manufacture. Air braked vehicles
manufactured prior to these dates, and vacuum braked vehicles would
continue to meet the requirements currently found at Sec. 393.50.
FMCSA believes the revision is necessary to indicate clearly that a
vehicle which is maintained to meet the reservoir requirements of FMVSS
No. 121 in effect on the date of manufacture would meet the
requirements under part 393. This is particularly important given the
NHTSA's January 12, 1995, final rule on FMVSS No. 121 (60 FR 2892).
NHTSA amended the reservoir requirements to facilitate the introduction
of long-stroke brake chambers. For vehicles manufactured on or after
February 13, 1995, the method for calculating the minimum air reservoir
capacity is based on either the rated volume of the brake chambers or
the volume of the brake chambers at the maximum travel of the brake
pistons or push rods, whichever is less.
Section 393.51--Warning Devices and Gauges
FMCSA revises Sec. 393.51 to provide better guidance on the
applicability of the warning device requirements to older commercial
motor vehicles. Hydraulic braked vehicles manufactured on or after
September 1, 1975, the effective date of FMVSS No. 105, are required to
meet the brake system indicator lamp requirements of FMVSS No. 571.105
(S5.3) applicable to the vehicle on the date of manufacture. Vehicles
manufactured before September 1, 1975, or to which FMVSS No. 571.105
was not applicable on the date of manufacture, must have a warning
signal which operates before or upon application of the brakes in the
event of a hydraulic-type complete failure of a partial system. The
language would retain all current requirements but add the effective
date for FMVSS No. 105 and identify the specific paragraph within FMVSS
No. 105 that covers warning devices.
In addition, FMCSA inserts a note into Sec. 393.51 to address the
warning device requirements for hydraulic braked trucks and buses
manufactured between October 12, 1976, and September 1, 1983. During
this period, FMVSS No. 105 was only applicable to passenger cars and
school buses. Consequently, manufacturers of hydraulic braked trucks
and buses were not required to equip those vehicles with a warning
device to indicate certain types of brake failure. However, under the
FMCSRs, motor carriers are responsible for having warning devices on
these vehicles. Because FMVSS No. 105 was not applicable to these
vehicles at the time of manufacture, the requirements of Sec. 393.51
are not in conflict with the NHTSA standard.
FHWA received numerous requests for interpretation from motor
carriers with vehicles manufactured during this period and not equipped
with a warning device. Through regulatory guidance, FHWA indicated that
these vehicles are required to be equipped with warning devices because
Sec. 393.51(b)(2)--which covers hydraulic braked vehicles to which
FMVSS No. 105 was not applicable at the time of manufacture--was in
effect prior to October 12, 1976, and has remained in effect ever
since. Therefore, the agency is codifying the regulatory guidance
concerning warning devices on these vehicles.
On the subject of air braked vehicles, FMCSA revises Sec.
393.51(c) to include reference to the March 1, 1975, effective date of
FMVSS No. 121 for power units. The specific paragraphs within FMVSS No.
121 which address the pressure gauge and warning signal requirements
are included. Vehicles which are not required to meet the requirements
of FMVSS No. 121 must be equipped with a pressure gauge, visible to a
person seated in the normal driving position, which indicates the air
pressure (in kilopascals (kPa) or pounds per square inch (psi))
available for braking; and, a warning signal that is audible or visible
to a person in the normal driving position and provides a continuous
warning to the driver whenever the air pressure in the service
reservoir system is at 379 kPa (55 psi) and below, or one-half of the
compressor governor cutout pressure, whichever is less.
With regard to commercial motor vehicles with hydraulic brakes
applied or assisted by air or vacuum, FMCSA revises Sec. 393.51(e) to
make it applicable only to hydraulic braked vehicles which were not
subject to the FMVSS No. 105 at the time of manufacture. The amendment
eliminates the inconsistency between the warning device requirements of
FMVSS No. 105 and Sec. 393.51(e). Currently, Sec. 393.51(e) requires
a warning device for the hydraulic portion of the brake system as well
as a warning device for the air or vacuum portion of the brake system,
irrespective of the applicability of FMVSS No. 105. However, FMVSS No.
105 does not require a warning device for the air or vacuum portion of
these hydraulic brake systems. FMCSA believes the Sec. 393.51(b)
cross-reference to FMVSS No. 105 provides effective requirements for
warning devices on hydraulic braked vehicles subject to that standard
at the time of manufacture. A requirement for an additional warning
device for the air or hydraulic portion of the brake system of these
vehicles is not necessary.
For air-assisted or vacuum-assisted hydraulic braked vehicles which
were not subject to FMVSS No. 105, FMCSA is retaining the current
requirements for a warning device for the hydraulic portion of the
brake system and a warning device for the air or vacuum portion of the
brake system. Section 393.51(e) would continue to require that the
hydraulic portion of the vehicle meet the requirements of Sec.
393.51(b) and that the air or vacuum portion of the brake system meet
the applicable requirements of paragraphs (c) or (d). FMCSA notes that
commercial motor vehicles equipped with air-over-hydraulic brake
systems are classified as air-braked vehicles and, as such, are
required to meet the applicable warning device and pressure gauge
requirements for air braked vehicles.
Finally, FMCSA reinstates one of the exemptions removed by the
December 7, 1988, final rule on part 393. The 1988 rule revised Sec.
393.51 by removing paragraph (g), which contained two exemptions
considered obsolete with the adoption of the definition of a commercial
motor vehicle. The exemptions covered buses with a seating capacity of
10 persons or less (including the driver), and two-axle property-
carrying vehicles that were either manufactured before July 1, 1973, or
had a GVWR of 4,536 kg (10,000 pounds) or less.
From a practical standpoint, all two-axle property-carrying
vehicles with a GVWR of 4,536 kg or less, and equipped with air,
vacuum, or air-assisted or vacuum-assisted hydraulic brake systems were
exempted irrespective of the date of manufacture. Generally, these
vehicles are only subject to the FMCSRs when transporting hazardous
materials in a quantity that requires placards on the vehicle or when
towing another vehicle such that the gross combination weight rating
exceeds 4,536 kg (10,000 pounds). Therefore, the exemption for certain
two-axle property-carrying vehicles is being reinstated, but is limited
to two-axle property-carrying vehicles manufactured before July 1, 1973.
Because the group of vehicles covered by the exemption represent a
small

[[Page 48020]]

segment of the total population of vehicles that fall under the FMCSA's
jurisdiction, and these vehicles have either reached, or will soon
reach the end of their service life and were previously exempted, the
reinstatement will not reduce safety on the highways. FMCSA is not
reinstating the exemption for buses with a seating capacity of 10 persons
or less because these vehicles are generally not subject to the FMCSRs.

Subpart D--Glazing and Window Construction

Sections 393.61, 393.62, 393.63, 393.92--Window Construction and
Emergency Exits
Section 393.61 is being revised to cover only truck and truck
tractor window construction. Window construction for buses (or
emergency exits) is covered under Sec. 393.62. The prohibitions on
window obstructions currently found at Sec. 393.62 is addressed along
with the emergency exits requirements. The provisions of Sec. 393.63
(Windows, markings) and Sec. 393.92 (Buses, marking emergency doors)
is covered under the revised rule on emergency exits. Sections 393.63
and 393.92 are removed.
In Sec. 393.61, FMCSA removes the reference to an ellipse in
determining the minimum area of a truck or truck-tractor window. The
rectangular dimensions currently provided appear to be sufficient.
Also, the rectangular dimensions provide the most practical and
enforceable criteria.
As for emergency exits on buses, FMCSA revises its cross-references
to FMVSS No. 217 so that motor carriers and enforcement officials will
have better guidance on the applicability of NHTSA's amendments to
buses subject to the FMCSRs. On November 2, 1992, FMVSS No. 217 was
amended to require that the minimum emergency exit space on school
buses be based upon the seating capacity of each bus (57 FR 49413).
NHTSA's final rule took effect September 1, 1994. Further, in a
separate notice, NHTSA allowed non-school buses to meet either the non-
school bus requirements or the new upgraded school bus requirements (57
FR 49444, November 2, 1992). NHTSA issued the final rule on May 9, 1995
(60 FR 24562).
FMCSA reviewed the NHTSA rulemakings and determined that the FMCSRs
should be amended to address the November 2, 1992, and May 9, 1995,
final rules. FMCSA is allowing the upgraded school bus emergency exit
requirements on buses subject to the FMCSRs so that motor carriers are
afforded the same flexibility given to manufacturers under FMVSS No. 217.
Buses manufactured on or after September 1, 1994, and having a GVWR
of 4,536 kg (10,000 pounds) or less must meet the emergency exit
requirements of FMVSS No. 217 (S5.2.2.3) in effect on the date of
manufacture. Generally, these buses would only be subject to the FMCSRs
when towing a trailer. If the gross combination weight rating (GCWR)
for the bus and trailer is greater than 4,536 kg, and the combination
is operated in interstate commerce, the emergency exit requirements are
applicable. An example is a small bus operated by a private motor
carrier of passengers when towing a trailer.
For buses with a GVWR of more than 4,536 kg (10,000 pounds), FMCSA
is requiring that they have emergency exits which meet the applicable
emergency exit requirements of FMVSS No. 217, S5.2.2 (the non-school
bus requirements) or S5.2.3 (the upgraded school bus requirements) in
effect on the date of manufacture. The provision for buses with a GVWR
greater than 4,536 kg incorporates NHTSA's final rules.
For buses manufactured on or after September 1, 1973, but before
September 1, 1994, the FMCSA is requiring that each bus (including a
school bus used in interstate commerce for non-school bus operations)
with a GVWR of more than 4,536 kg (10,000 pounds) meet the requirements
of FMVSS No. 217, S5.2.2, in effect on the date of manufacture. Buses
with a GVWR of 4,536 kg (10,000 pounds) or less must meet the requirements
of FMVSS No. 217, S5.2.2.3, in effect on the date of manufacture.
Section 393.62 is revised to include a paragraph on emergency exit
identification. Each bus and each school bus used in interstate
commerce for non-school bus operations, manufactured on or after
September 1, 1973, must meet the applicable emergency exit
identification or marking requirements of FMVSS No. 217, S5.5, in
effect on the date of manufacture. Buses (including school buses used
in interstate commerce for non-school bus operations) must be marked
``Emergency Exit'' or ``Emergency Door'' followed by concise operating
instructions describing each motion necessary to unlatch or open the
exit located within 152 mm (6 inches) of the release mechanism.
The emergency exit requirements for buses manufactured before
September 1, 1973, is revised to provide requirements which are easier
to understand and enforce. These buses must have either laminated
safety glass or push-out windows. The regulation would more clearly
state that laminated safety glass would, at a minimum, be required to
meet Test No. 25, Egress, of the American National Standards Institute
(ANSI), American National Standard for Safety Glazing Materials for
Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land
Highways-Safety Standard, ANSI/SAE Z26.1/1996 (ANSI approved August
1997). FMCSA incorporates the ANSI document by reference.
With regard to push-out windows, the requirements are revised to
adopt certain provisions of FMVSS No. 217. Each push-out window is
required to be releasable by operating no more than two mechanisms and
allow manual release of the exit by a single occupant. For mechanisms
which require rotary or straight (parallel to the undisturbed exit
surface) motions to operate the exit, the amount of force required to
release the exit could not exceed 89 Newtons (20 pounds). For exits
which require a straight motion perpendicular to the undisturbed exit
surface, the amount of force could not exceed 267 Newtons (60 pounds).
FMCSA believes the force requirements will not present a problem
for motor carriers and that older buses with emergency exits which
cannot meet these basic performance requirements should have the
emergency exit release mechanisms replaced. This should not be
construed as an attempt to require that the entire emergency exit be
replaced, only release mechanisms which do not meet the criteria.
Lastly, FMCSA codifies its regulatory guidance on buses used for
the transportation of prisoners. An exception to the emergency exit
requirements is included for buses used exclusively for the
transportation of prisoners.

Subpart E--Fuel Systems

Section 393.67--Liquid Fuel Tanks
FMCSA revises paragraph (a) to indicate that the fuel tank
requirements apply not only to tanks containing or supplying fuel for
the operation of commercial motor vehicles, but includes tanks needed
for the operation of auxiliary equipment installed on, or used in
connection with commercial motor vehicles. Section 393.65(a), the
requirements for fuel systems, contains similar language so FMCSA
amends the applicability statement of Sec. 393.67 to be consistent
with Sec. 393.65.
Also, FMCSA revises Sec. 393.67(d) and (e) to include the
information currently presented in a footnote to the section.

[[Page 48021]]

As indicated by the footnote, the fuel tank tests specified by Sec.
393.67 are a measure of performance only. Alternative procedures which
assure that the fuel tank meets the performance criteria may be used.
However, this footnote is often overlooked. Including the text of the
footnote in paragraphs (d) and (e) would help to prevent further confusion.
In addition, FMCSA corrects an error in Sec. 393.67(f)(2).
Currently, each liquid fuel tank manufactured on or after July 1, 1988,
must be marked with the manufacturer's name. The July 1, 1988, date is
incorrect. This date precedes the publication of the December 7, 1988,
final rule that established the July 1, 1988 compliance date. The last
number in the year should have been a ``9'' instead of an ``8.'' FMCSA
intended the date to read July 1, 1989, approximately 120 days after
the March 7, 1989, effective date of the December 7, 1988, final rule
on part 393.
Section 393.68--Compressed Natural Gas Fuel Containers
FMCSA creates a new section to address requirements for compressed
natural gas (CNG) fuel containers. Section 393.68 cross-references the
NHTSA's new requirements for CNG containers, FMVSS No. 304, Compressed
Natural Gas Fuel Container Integrity (September 26, 1994, 59 FR 49010).
Under FMVSS No. 304, which is applicable to all CNG containers
manufactured on or after March 26, 1995, CNG fuel containers must meet
a pressure cycling test which evaluates the container's durability, a
burst test to measure its strength, and a fire test to ensure adequate
pressure relief characteristics. The rule also specifies labeling
requirements.
FMCSA has reviewed the NHTSA requirements and determined that all
commercial motor vehicles manufactured on or after March 26, 1995, and
equipped with CNG fuel tanks, should be required to be maintained to
meet the applicable requirements of FMVSS No. 304.

Subpart F--Coupling Devices and Towing Methods

Section 393.70--Coupling Devices and Towing Methods, Except for
Driveaway-Towaway Operations
Currently Sec. 393.70(d) provides requirements for the attachment
of safety devices in case of tow-bar failure. If two chains or cables
are attached to the same point on the towing vehicle, or if a bridle or
a single chain or cable is used, the point of attachment must be on the
longitudinal centerline of the towing vehicle. A single safety device,
other than a chain or cable, must also be attached to the towing
vehicle at a point on its longitudinal centerline.
Western Trailers petitioned FHWA to amend Sec. 393.70(d)(8) to
allow safety devices to be attached as close as practicable to the
longitudinal centerline of the towing vehicle. The petition is
available for review in the docket. The petitioner argued that because
the pintle hook is mounted on the longitudinal centerline of the towing
vehicle, there is no practical centerline mounting position for the
safety chain/cable attachment except upon or above the pintle hook itself.
In reviewing the history of the requirements for safety chains from
1941 through the present, FMCSA notes that a certain amount of
flexibility had been allowed so that chains could be attached as close
as ``practicable'' to the centerline. Although the current
requirements, adopted on October 11, 1972 (37 FR 21439), do not appear
to have created problems for other carriers, FMCSA agrees that there is
a need to reexamine the requirement and eliminate any unnecessary
restrictions. To that end, FMCSA believes that specifying the location
for attachment point of the safety devices with such precision is
unnecessarily design-restrictive.
The attachment of the safety devices to a point as close as
``practicable'' to the centerline, is needed to ensure that the
combination of vehicles will maintain as much stability as possible in
the event the coupling device fails. However, given the size and weight
of a typical commercial motor vehicle, there is little technical
justification for prohibiting attachment of the safety devices at a
point within a few centimeters (or inches) off the centerline. In fact,
failure of the coupling device at its centerline point of attachment to
the towing vehicle might damage the anchor point of the safety chains,
possibly resulting in complete separation of the trailer.
In addition, the current language of Sec. 393.70(d)(8) may, under
some circumstances, be inconsistent with Sec. 393.70(d)(1), which
prohibits the attachment of the safety device to the pintle hook or any
other device on the towing vehicle to which a tow-bar is attached.
The previous provisions of Sec. 393.70 provided a performance-
based requirement while ensuring the safety of operation of the
combination of vehicles. The language used, however, may have been
difficult to enforce, in that ``practicability'' is a subjective term.
This generally results in differences of opinion between vehicle
manufacturers, motor carriers, and Federal and State enforcement
officials as to what constitutes compliance. The amended rule allows
the attachment point to be offset no more than a specified distance
from the longitudinal centerline and provides flexibility without
adversely affecting the tracking of the towed unit in the event of a
pintle hook failure. FMCSA notes that the safety device is only
intended to keep the combination of vehicles together if the pintle
hook or other coupling device fails, and then only for a brief period
until the driver brings the vehicle to a safe stop. Therefore, the
change will not affect the safety of operation of the vehicles.
FMCSA is allowing safety chains or cables to be attached to the
longitudinal centerline or within 152 mm (6 inches) to the right of the
longitudinal centerline on the towing vehicle. This is applicable when:
(1) Two chains or cables are attached to the same point on the towing
vehicle; (2) a bridle or a single chain or cable is used; or (3) a
single safety device is used. Given the wide variety of vehicle
configurations and the condition of loading at the time of a potential
tow-bar or pintle hook failure, the current design-restrictive
requirement does not appear to ensure a greater degree of safety than
the revision. Allowing the safety device to be no more than 152 mm (6
inches) from the longitudinal centerline should provide additional
safety benefits in a few cases without changing the level of safety
guaranteed by the current centerline requirement in other cases. It
would also result in a requirement that is more performance-based and
less design-restrictive.
Section 393.71--Coupling Devices and Towing Methods, Driveaway-Towaway
Operations
Section 393.71(a) currently prohibits the use of more than one tow-
bar in any combination of vehicles. Section 393.71(g)(2) indicates that
coupling devices, such as those used for towing house trailers and
employing ball and socket connections, shall be considered as tow-bars.
However, the broad classification of ball and socket connections as
tow-bars is not consistent with the definitions of the Society of
Automotive Engineers. As a result, the use of more than one ball-and-
socket connection in a combination of vehicles is prohibited. This
situation is being clarified through this final rule.
FMCSA considers the stability and control of a combination vehicle
using multiple ball-and-socket connections no better than that of a
combination using multiple tow-bars. Given that the

[[Page 48022]]

stability and control would, at best, be comparable to a towing method
which is prohibited, FMCSA is amending Sec. 393.71(a)(2) to prohibit
the use of more than one tow-bar and/or ball-and-socket coupling device
in any combination. Section 393.71(g)(2) is being removed.
To improve the consistency between Section 393.70 and 393.71, the
FMCSA amends Sec. 393.71(b) by adding a new provision addressing
weight distribution of towing and towed vehicles for saddle-mount
combinations.
Sections 393.70(b)(3), 393.71(b)(2) and 393.71(c)(3) address the
proper weight distribution and require that the coupling arrangement be
such that it does not unduly interfere with the steering, braking, and
maneuvering of the combination of vehicles. Section 393.70(b)(3) covers
the use of fifth wheels for non-driveaway-towaway operations and
Sec. Sec. 393.71(b)(2) and (c)(3) cover full-mounted vehicles in
driveaway-towaway operations. Section 393.71(b) does not, however,
explicitly require that the arrangement of the saddle-mounted vehicles
be such that it does not unduly interfere with the steering, braking
and maneuvering of the combination of vehicles. The references to undue
interference with steering, braking, and maneuvering in Sec. Sec.
393.70 and 393.71 suggest that such requirements are generally intended
for any vehicle configuration covered by these sections. Through
regulatory guidance, the agency had indicated that saddle-mounted
vehicles are to be arranged such that the gross weight of the vehicles
is properly distributed to prevent the conditions currently covered by
Sec. Sec. 393.70(b)(3), 393.71(b)(2) and 393.71(c)(3). FMCSA is now
codifying this guidance in Sec. 393.71(b)(3).
FMCSA revises Sec. 393.71(g) to remove obsolete language and
provide more technically sound guidance on towing methods. Section
393.71(g)(1) currently requires the use of a tow-bar or saddle-mount
connection for all vehicles towed in driveaway-towaway operations. This
is inappropriate for towing semitrailers designed to be coupled to a
fifth wheel. Through regulatory guidance, the agency has allowed the
use of a fifth wheel. The agency codifies this guidance by revising
Sec. 393.71(g) to explicitly allow the use of a fifth wheel.

Subpart G--Miscellaneous Parts and Accessories

Section 393.75--Tires
FMCSA amends Sec. 393.75(e) in order to make the requirements
easier to understand. Section 393.75(e) prohibits the use of regrooved
tires which have a load carrying capacity greater than that of 8.25-20
8 ply-rating tires, but does not specify the load range rating for
these tires. According to the Tire and Rim Association's 2003 Year
Book, an 8.25-20 bias ply tire has a maximum load carrying capacity of
2,232 kg (4,920 pounds) at 793 kPa (115 psi) cold inflation pressure.
This maximum capacity applies to tires of load range G. Tires with the
load range of E and F have maximum load carrying capacities of 1,837 kg
(4,050 pounds) and 2,041 kg (4,500 pounds), respectively. FMCSA will
now use 2,232 kg limit under Sec. 393.75. The difference in load
carrying capacity between a tire rated load range E and one rated load
range G is 395 kg (870 pounds). In the absence of tire overloading, the
difference in the amount of front axle loading between an axle equipped
with load range E tires and a front axle equipped with load range G
tires is 790 kg (1,740 pounds). There is no apparent safety benefit
from adopting the more stringent limit of load range E for regrooved
tires. Therefore, the use of a regrooved tire with a load carrying
capacity equal to or greater than 2,232 kg (4,920 pounds) is a
violation of Sec. 393.75(e) if used on the front wheels of a truck or
truck tractor.
FMCSA notes that a radial ply tire of the same size and load range
(i.e., 8.25R20) has the same load carrying capacity, but at 827 kPa
(120 psi) cold inflation pressure. Because the prohibition is based on
load carrying capacity, FMCSA is replacing the reference to a specific
tire size with the 2,232 kg (4,920 pound) value currently listed in the
Tire and Rim Association's publication.
Section 393.78 Windshield Wipers
FMCSA amends Sec. 393.78 to cross-reference FMVSS No. 104. The
NHTSA requirement has been in effect since December 1968. Because
vehicle manufacturers have been required to meet the requirements since
1968, FMCSA does not believe that motor carriers who have maintained
their commercial motor vehicles should have any problem complying with
the new rule. As for motor vehicles manufactured before December 1968,
they are required to be equipped with a power-driven windshield wiping
system with at least two wiper blades, one on each side of the
centerline of the windshield. Motor vehicles which depend upon vacuum
to operate the windshield wipers must have the wiper system constructed
and maintained such that the performance of the wipers would not be
adversely affected by a change in the intake manifold pressure. The
requirements for vehicles manufactured before December 1968 were
originally established by the former Interstate Commerce Commision and
were applicable to vehicles manufactured on and after June 30, 1953.
FMCSA removes the exemption for the towing vehicle in a driveaway-
towaway operation because there is no justification for allowing a
vehicle to be driven without both windshield wipers in proper working
order. The change should not result in an increased economic burden on
the motor carrier industry.
Section 393.79--Windshield Defrosting Device
Section 393.79 is revised to cross-reference FMVSS No. 103.
Vehicles manufactured on or after December 25, 1968, are required to
meet the requirements in effect on the date of manufacture. Vehicles
manufactured before December 25, 1968, are required, at a minimum, to
be equipped with a means for preventing the accumulation of ice, snow,
frost, or condensation to obstruct the driver's view through the
windshield while the vehicle is being driven.
In addition, the exemption for the towing vehicle in a driveaway-
towaway operation is removed. There is no justification for allowing a
vehicle to be driven without a windshield defrosting device in proper
working order.
Section 393.82--Speedometer
Section 393.82 requires that every bus, truck, and truck-tractor be
equipped with a speedometer indicating speed in miles per hour.
Speedometers must operate with ``reasonable accuracy.'' Appendix A to
subchapter B (prior to its removal from the FMCSRs on November 23, 1994
(59 FR 60319)) interpreted as ``reasonable'' an accuracy of plus or
minus 8 km/hr (5 mph) at a speed of 80 km/hr (50 mph). The
interpretation indicated that accuracy within these limits is
sufficient for a professional driver to ascertain the true speed of the
vehicle. FMCSA is including this accuracy limit in Sec. 393.82 to make
the requirement easier to understand. FMCSA is also removing the
driveaway-towaway exemption to the speedometer requirements because
there is no justification for allowing a vehicle to be driven without a
speedometer in proper working order. The changes should not result in
an increased economic burden on the motor carrier industry.

[[Page 48023]]

Section 393.87--Flags on Projecting Loads
Section 393.87 is being revised to make the requirements consistent
with the American Association of State Highway and Transportation
Officials' (AASHTO) Guide for Maximum Dimensions and Weights of Motor
Vehicles and for the Operation of Nondivisible Load Oversize and
Overweight Vehicles, GSW-3, 1991. The AASHTO publication provides
guidance on the use of warning flags for vehicles and loads which
exceed legal width or length, or which have a rear overhang in excess
of the legal limit. The AASHTO guidelines call for the use of red or
orange fluorescent warning flags which are at least 457 mm (18 inches)
square. Because the AASHTO guide appears to cover the majority of the
cases to which the current rule is applicable, and represents a
consensus of State and industry practices, FMCSA is revising Sec.
393.87 to adopt certain provisions of those guidelines.
Commercial motor vehicles transporting loads which extend beyond
the sides by more than 102 mm (4 inches) or more than 1,219 mm (4 feet)
beyond the rear must have the extremities of the load marked with red
or orange fluorescent warning flags. Each warning flag must be at least
457 mm (18 inches) square as opposed to the current requirement of 305
mm (12 inches) square.
With regard to the number of flags and their positions, a single
flag at the extreme rear is required if the projecting load is 610 mm
(2 feet) wide or less. Two warning flags are required if the projecting
load is wider than 610 mm. Flags are required to be positioned to
indicate maximum width of loads which extend beyond the sides and/or
rear of the vehicle.
Section 393.94--Vehicle Interior Noise Level
FMCSA simplifies its regulation concerning the applicability of the
interior noise levels in commercial motor vehicles. Section 393.94(a)
and (d) make reference to certain vehicles manufactured before October
1, 1974, and grant motor carriers until April 1, 1975, to comply with
the regulation. For vehicles operated wholly within Hawaii, carriers
were given until April 1, 1976, to comply. Because these deadlines have
passed, FMCSA is deleting the references from Sec. 393.94. In
addition, FMCSA is updating the reference to the American National
Standards Institute (ANSI) specifications for sound level meters.
Currently, Sec. 393.94 references the 1971 version of ANSI S1.4,
Specification for Sound Level Meters. FMCSA incorporates by reference
the 1983 version and removing the footnote to paragraph (c).
Information on the availability of the ANSI document is covered under
Sec. 393.7.
Section 393.95--Emergency Equipment on All Power Units
FMCSA eliminates the reference to lightweight vehicles in paragraph
(a). The term became obsolete when the agency implemented the
requirements of the Motor Carrier Safety Act of 1984 (49 U.S.C. 31131
et. seq.) and limited the applicability of part 393 to ``commercial
motor vehicles'' as defined in that statute (53 FR 18042, May 19,
1988). Sections 393.95(a)(2)(i) and (a)(2)(ii) are being amended to
remove obsolete references to vehicles equipped with fire extinguishers
prior to July 1, 1971, and January 1, 1973, respectively. While some of
these vehicles are still in operation, it is unlikely that the motor
carriers are still using fire extinguishers that are more than 30 years
old.
FMCSA revises Sec. 393.95 to remove the specifications for
bidirectional warning triangles manufactured prior to January 1, 1974.
Such triangles are already prohibited on any vehicle manufactured on or
after January 1, 1974. Therefore, only those carriers operating
commercial motor vehicles manufactured before January 1, 1974, and
equipped with warning triangles manufactured before that date, are
affected.
FMCSA revises the requirements on the mounting of fire
extinguishers to provide more specific guidance. Fire extinguishers are
required to be securely mounted to prevent sliding, rolling, or
vertical movement relative to the motor vehicle. Currently, Sec.
393.95(a)(1) states only that the extinguisher be securely mounted.
With regard to extinguishing agents, FMCSA replaces the reference
to the Underwriters Laboratories' (UL) Classification of Comparative
Life Hazard of Gases and Vapors. The UL study was conducted in the
1950's and is considered obsolete information. UL has recommended that
the FMCSA consider referencing the Environmental Protection Agency's
regulations under Subpart G of 40 CFR part 82, Protection of
Stratospheric Ozone. Subpart G implements section 612 of the Clean Air
Act (42 U.S.C. 7401 et seq.) by determining safe alternatives to ozone-
depleting compounds. It is usually referred to as the ``Significant New
Alternatives Policy'' (SNAP) program. The SNAP regulations take into
consideration the toxicity of substitutes for ozone-depleting
compounds, but they also address potential impacts on atmospheric
ozone, global warming and other issues related to human exposure and
the environment. FMCSA is therefore requiring that fire extinguishers
comply with the toxicity provisions of the SNAP regulations. While the
other issues (ozone depletion, global warming, etc.) are important,
there is no practical reason to address these issues in Sec. 393.95.
Section 393.201--Frames
In its final rule published on December 7, 1988 (53 FR 49380), FHWA
prohibited cracked, loose, sagging or broken frames. However, the
agency inadvertently failed to include trailer frames. FMCSA amends
Sec. 393.201 to remedy this oversight by replacing ``bus, truck and
truck-tractor'' with the term ``commercial motor vehicles'' in
paragraph (a).
FMCSA revises Sec. 393.201(d) to make the regulation more
practical. Paragraph (d) was intended to prohibit welding on vehicle
frames constructed of certain types of steel which is weakened by the
welding process. However, the current wording is overly restrictive. To
address this issue, paragraph (d) is being revised to allow welding
which is performed in accordance with the vehicle manufacturer's
recommendations.
In addition, FMCSA removes paragraph (f). Paragraph (f) states that
field repairs are allowed. There is no practical reason for retaining
this provision since there was never a requirement that the motor
carrier repair its vehicle only at certain locations.
Section 393.207--Suspension Systems
In response to a petition from the Truck Trailer Manufacturers
Association (TTMA), FMCSA is amending Sec. 393.207 to prohibit any
device which is capable of dumping air individually from either of the
two axle suspension systems on a semitrailer equipped with air-
suspended ``spread'' or ``split'' tandem axles. TTMA indicated that the
petition was not intended to prohibit: (1) Devices that could exhaust
air from both axle systems simultaneously, or (2) lift axles on multi-
axle units. The petition is available for review in the docket.
According to the TTMA, about 30,000 semitrailers are manufactured
each year with split tandem axles and air suspensions. These axles are
not genuine tandems, but rather two single axles spaced at least 3,048
mm (10 feet) apart, the minimum separation required by the bridge
formula [23 U.S.C. 127(a)] before each of them can carry the full 9,072
kg (20,000 pounds) allowed by

[[Page 48024]]

Federal law. The TTMA estimates that 5,000 of these trailers are also
equipped with valves to depressurize the suspension system of one of
the trailer axles, and sometimes of either axle. These valves are
installed to compensate for problems created by the split tandem
configuration. Normal tandems experience moderate tire scrubbing in
turns because the trailer pivots around a point that lies between the
two axles. Tire scrubbing is more severe in split tandems because the
pivot point is much farther from either axle. Dumping air pressure from
the suspension system of the rear (or less often the leading) trailer
axle reduces its load and allows the trailer to pivot around the other
axle with less resistance and tire scrubbing. The TTMA's own tests
showed that if each axle in a split tandem is loaded to 8,845 kg
(19,500 pounds) and pressure in the rear axle is dumped, the resulting
weight shift will make the front axle 3,175 to 5,443 kg (7,000 to
12,000 pounds) heavier than the rear.
Dump valves were originally designed to aid maneuvering at 8 km/
hour (5 mph) or less, mainly at terminals or other loading points.
According to the TTMA, however, many drivers now activate them at
higher speeds on streets and highways to turn corners more easily and
to reduce tire wear. The TTMA also believes that suspension pressure is
sometimes vented accidentally because of wiring problems the moment the
tractor hooks up to the trailer. In both cases, the inevitable weight
shift often produces a load on the pressurized axle that exceeds the
manufacturers' ratings for that axle and its wheels, tires and brakes.
In addition, the loaded axle frequently exceeds the single-axle weight
limit.
FMCSA continues to believe the petition has merit, and the agency
is amending Sec. 393.207 to prohibit controls of this type. Although
Sec. 393.3, which allows the use of equipment and accessories that do
not decrease operational safety, could be interpreted as prohibiting
the use of equipment to disable the air suspension of one axle on a
two-axle trailer, addressing this issue through rulemaking is the most
appropriate course of action.
FMCSA has modified the language included in the 1997 NPRM in
response to comments from the ATA. ATA agreed with the proposal, but
expressed concern that motor carriers need the flexibility to exhaust
air from the suspension during low-speed turns. ATA believes this is
necessary because there is significant resistance or tire scrubbing
when drivers make low-speed turning maneuvers with a spread tandem
trailer. FMCSA agrees and has revised the language to allow the
exhausting of air if the controls are either located on the trailer, or
the power unit and trailer combination are not capable of traveling at
a speed greater than 10 miles per hour while the air is exhausted from
the suspension system.
Section 393.209--Steering Wheel Systems
FMCSA amends Sec. 393.209(b) to correct an error in the maximum
steering wheel lash for 406 mm (16 inch) steering wheels and to add
steering wheel lash limits for 483 mm (19 inch) and 533 mm (21 inch)
diameter steering wheels. The table specifying steering wheel lash
limits currently allows 114 mm (4\1/2\ inches) lash for steering wheel
diameters of 406 mm (16 inches) or less if the vehicle has a power
steering system. This corresponds to an angle of approximately 32
degrees which is about 2 degrees more than the steering wheel lash
limits for power steering systems using larger diameter steering
wheels. Because there is no apparent technical basis for having a less
stringent standard for 406 mm (16 inch) diameter steering wheel
systems, FMCSA is changing the steering wheel lash limit to 108 mm
(4\1/4\ inches).
FMCSA adds steering wheel lash limits for 483 mm (19 inch) and 533
mm (21 inch) diameter steering wheels because these are relatively
common steering wheel sizes. The limits being adopted for these
steering wheel diameters is consistent with the 14 degree and 30 degree
limits currently used for manual and power steering systems respectively.
Section 393.209 is amended to include the term ball-and-socket
joints. Some steering system designs include ball-and-socket joints
instead of universal joints. While the basic function of the two types
of joints is similar, only universal joints are covered by Sec.
393.209(d). Defects or unsafe conditions of ball-and-socket joints are
currently implicitly covered under Sec. 396.3(a)(1). The agency
believes that such important items should be explicitly covered
whenever possible.

Regulatory Analyses and Notices

Executive Order 12866 (Regulatory Planning and Review) and DOT
Regulatory Policies and Procedures

FMCSA has determined that this action is not a significant
regulatory action within the meaning of Executive Order 12866 or within
the meaning of Department of Transportation regulatory policies and
procedures. This document is not required to be reviewed by the Office
of Management and Budget. Because the rulemaking is focused on
improving the clarity of the safety requirements in general, and
improving the cross-references between the FMCSRs and FMVSSs, the final
rule will not result in costs to the industry. A regulatory evaluation
has been prepared by the Agency and is available in the docket.

Regulatory Flexibility Act

In compliance with the Regulatory Flexibility Act (5 U.S.C. 601-
612), FMCSA has considered the effects of this regulatory action on
small entities and determined that this rule will not have a
significant impact on a substantial number of small entities, as
defined by the U.S. Small Business Administration's Office of Size
Standards. This final rule makes amendments and revisions to parts 390,
392, and 393 of the FMCSRs to remove obsolete and redundant
regulations; respond to several petitions for rulemaking; provide
improved definitions of vehicle types, systems, and components; resolve
inconsistencies between part 393 and NHTSA's FMVSSs under 49 CFR part
571; and codify certain FMCSA regulatory guidance concerning the
requirements of part 393. Generally, the amendments do not involve the
establishment of new or more stringent requirements, but a
clarification of existing requirements. This action is intended to make
many sections more concise, easier to understand and more performance
oriented. Accordingly, FMCSA has considered the economic impacts of the
rulemaking on small entities and certifies that this rule will not have
a significant economic impact on a substantial number of small
entities. A regulatory flexibility analysis has been prepared by the
Agency and is available in the docket.

Unfunded Mandates Reform Act of 1995

This rulemaking will not impose an unfunded Federal mandate, as
defined by the Unfunded Mandates Reform Act of 1995 (2 U.S.C. Sec.
1532 et seq.), that will result in the expenditure by State, local, and
tribal governments, in the aggregate, or by the private sector, of
$120.7 million or more in any 1 year.

Executive Order 12988 (Civil Justice Reform)

This action will meet applicable standards in sections 3(a) and
3(b)(2) of Executive Order 12988, Civil Justice Reform, to minimize
litigation,

[[Page 48025]]

eliminate ambiguity, and reduce burden.

Executive Order 13045 (Protection of Children)

FMCSA has analyzed this action under Executive Order 13045,
Protection of Children from Environmental Health Risks and Safety
Risks. This rulemaking will not concern an environmental risk to health
or safety that may disproportionately affect children.

Executive Order 12630 (Taking of Private Property)

This rulemaking will not effect a taking of private property or
otherwise have taking implications under Executive Order 12630,
Governmental Actions and Interference with Constitutionally Protected
Property Rights.

Executive Order 13132 (Federalism)

This action has been analyzed in accordance with the principles and
criteria contained in Executive Order 13132. It has been determined
that this rulemaking will not have a substantial direct effect on
States, nor will it limit the policy-making discretion of the States.
Nothing in this document will preempt any State law or regulation.

Executive Order 12372 (Intergovernmental Review)

Catalog of Federal Domestic Assistance Program Number 20.217, Motor
Carrier Safety. The regulations implementing Executive Order 12372
regarding intergovernmental consultation on Federal programs and
activities do not apply to this program.

Paperwork Reduction Act

This final rule does not contain a collection of information
requirement for the purposes of the Paperwork Reduction Act of 1995, 44
U.S.C. 3501 et seq.

National Environmental Policy Act

We have analyzed this action for purposes of the National
Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.) and have
determined that this action will not have an effect on the quality of
the environment. However, an environmental assessment (EA) is required
because the rulemaking is not among those covered by a categorical
exclusion. A copy of the EA is included in the docket referenced at the
beginning of this notice.
In accordance with the National Environmental Policy Act and the
Council of Environmental Quality Regulations (40 CFR parts 1500-1508),
the agency has prepared a finding of no significant impact (FONSI). A
copy of the FONSI is included in the docket at the beginning of this
notice.

Executive Order 13211 (Energy Effects)

We have analyzed this action under Executive Order 13211, Actions
Concerning Regulations That Significantly Affect Energy Supply,
Distribution or Use. We have determined that it will not be a
``significant energy action'' under that order because it will not be
economically significant and would not be likely to have a significant
adverse effect on the supply, distribution, or use of energy.

List of Subjects

49 CFR Part 390

Highway safety, Highways and roads, Intermodal transportation,
Motor carriers, Motor vehicle identification, Motor vehicle safety,
Reporting and recordkeeping requirements.

49 CFR Part 392

Highway safety, Highways and roads, Motor carriers--driving
practices, Motor vehicle safety.

49 CFR Part 393

Highways and roads, Incorporation by reference, Motor carriers,
Motor vehicle equipment, Motor vehicle safety.

Issued on: July 13, 2005.
Annette M. Sandberg,
Administrator.

? In consideration of the foregoing, FMCSA amends title 49, Code of
Federal Regulations, subchapter B, chapter III, as follows:

PART 390--[AMENDED]

? 1. The authority citation for part 390 continues to read as follows:

Authority: 49 U.S.C. 508, 13301, 13902, 31133, 31136, 31502,
31504, and sec. 204, Pub. L. 104-88, 109 Stat. 803, 941 (49 U.S.C.
701 note); sec. 114, Pub. L. 103-311, 108 Stat. 1673, 1677; sec.
217, Pub. L. 106-159, 113 Stat. 1748, 1767; and 49 CFR 1.73.

? 2. Section 390.5 is amended by revising the definition of driveaway-
towaway operation to read as follows:

Sec. 390.5 Definitions.

* * * * *
Driveaway-towaway operation means an operation in which an empty or
unladen motor vehicle with one or more sets of wheels on the surface of
the roadway is being transported:
(1) Between vehicle manufacturer's facilities;
(2) Between a vehicle manufacturer and a dealership or purchaser;
(3) Between a dealership, or other entity selling or leasing the
vehicle, and a purchaser or lessee;
(4) To a motor carrier's terminal or repair facility for the repair
of disabling damage (as defined in Sec. 390.5) following a crash; or
(5) To a motor carrier's terminal or repair facility for repairs
associated with the failure of a vehicle component or system; or
(6) By means of a saddle-mount or tow-bar.
* * * * *

PART 392--[AMENDED]

? 3. The authority citation for part 392 continues to read as follows:

Authority: 49 U.S.C. 13902, 31136, 31502; and 49 CFR 1.73.

? 4. Section 392.33 is revised to read as follows:

Sec. 392.33 Obscured lamps or reflective devices/material.

(a) No commercial motor vehicle shall be driven when any of the
lamps or reflective devices/material required by subpart B of part 393
of this title are obscured by the tailboard, or by any part of the load
or its covering, by dirt, or other added vehicle or work equipment or
otherwise.
(b) Exception. The conspicuity treatments on the front end
protection devices of the trailer may be obscured by part of the load
being transported.

PART 393--[AMENDED]

? 5. The authority citation for part 393 continues to read as follows:

Authority: 49 U.S.C. 322, 31136, and 31502; Section 1041(b) of
Pub. L. 102-240, 105 Stat. 1914, 1993 (1991); and 49 CFR 1.73.

? 6. Section 393.1 is revised to read as follows:

Sec. 393.1 Scope of the rules in this part.

(a) The rules in this part establish minimum standards for
commercial motor vehicles as defined in Sec. 390.5 of this title. Only
motor vehicles (as defined in Sec. 390.5) and combinations of motor
vehicles which meet the definition of a commercial motor vehicle are
subject to the requirements of this part. All requirements that refer
to motor vehicles with a GVWR below 4,536 kg (10,001 pounds) are
applicable only when the motor vehicle or combination of motor vehicles
meets the definition of a commercial motor vehicle.
(b) Every employer and employee shall comply and be conversant with
the requirements and specifications of this part. No employer shall
operate a

[[Page 48026]]

commercial motor vehicle, or cause or permit it to be operated, unless
it is equipped in accordance with the requirements and specifications
of this part.

? 7. Section 393.5 is amended by removing the definitions of ``bus'' and
``container chassis''; and by adding in alphabetical order definitions
for ``air brake system,'' ``air-over-hydraulic brake system,''
``auxiliary driving lamp,'' ``boat trailer,'' ``brake power assist
unit,'' ``brake power unit,'' ``container chassis trailer,'' ``electric
brake system,'' ``emergency brake,'' ``front fog lamp,'' ``hydraulic
brake system,'' ``multi-piece windshield,'' ``split service brake
system,'' ``tow bar,'' ``trailer kingpin,'' ``vacuum brake system,''
``windshield''; and by revising the definitions of ``chassis,''
``clearance lamp,'' ``heater,'' ``heavy hauler trailer,'' ``parking
brake system,'' ``side marker lamp (intermediate),'' and ``side marker
lamps'' to read as follows:

Sec. 393.5 Definitions.

* * * * *
Air brake system. A system, including an air-over-hydraulic brake
subsystem, that uses air as a medium for transmitting pressure or force
from the driver control to the service brake, but does not include a
system that uses compressed air or vacuum only to assist the driver in
applying muscular force to hydraulic or mechanical components.
Air-over-hydraulic brake subsystem. A subsystem of the air brake
system that uses compressed air to transmit a force from the driver
control to a hydraulic brake system to actuate the service brakes.
* * * * *
Auxiliary driving lamp. A lighting device mounted to provide
illumination forward of the vehicle which supplements the upper beam of
a standard headlighting system. It is not intended for use alone or
with the lower beam of a standard headlamp system.
* * * * *
Boat trailer. A trailer designed with cradle-type mountings to
transport a boat and configured to permit launching of the boat from
the rear of the trailer.
* * * * *
Brake power assist unit. A device installed in a hydraulic brake
system that reduces the operator effort required to actuate the system,
but which if inoperative does not prevent the operator from braking the
vehicle by a continued application of muscular force on the service
brake control.
Brake power unit. A device installed in a brake system that
provides the energy required to actuate the brakes, either directly or
indirectly through an auxiliary device, with the operator action
consisting only of modulating the energy application level.
* * * * *
Chassis. The load-supporting frame of a commercial motor vehicle,
exclusive of any appurtenances which might be added to accommodate cargo.
Clearance Lamps. Lamps that provide light to the front or rear,
mounted on the permanent structure of the vehicle, such that they
indicate the overall width of the vehicle.
Container chassis trailer. A semitrailer of skeleton construction
limited to a bottom frame, one or more axles, specially built and
fitted with locking devices for the transport of intermodal cargo
containers, so that when the chassis and container are assembled, the
units serve the same function as an over the road trailer.
* * * * *
Electric brake system. A system that uses electric current to
actuate the service brake.
Emergency brake. A mechanism designed to stop a motor vehicle after
a failure of the service brake system.
* * * * *
Front fog lamp. A lighting device whose beam provides downward
illumination forward of the vehicle and close to the ground, and is to
be used only under conditions of rain, snow, dust, smoke or fog. A pair
of fog lamps may be used alone, with parking, tail, side, marker,
clearance and identification lamps, or with a lower beam headlamp at
the driver's discretion in accordance with state and local use law.
* * * * *
Heater. Any device or assembly of devices or appliances used to
heat the interior of any motor vehicle. This includes a catalytic
heater which must meet the requirements of Sec. 177.834(l)(2) of this
title when Class 3 (flammable liquid) or Division 2.1 (flammable gas)
is transported.
Heavy hauler trailer. A trailer which has one or more of the
following characteristics, but which is not a container chassis trailer:
(1) Its brake lines are designed to adapt to separation or
extension of the vehicle frame; or
(2) Its body consists only of a platform whose primary cargo-
carrying surface is not more than 1,016 mm (40 inches) above the ground
in an unloaded condition, except that it may include sides that are
designed to be easily removable and a permanent ``front-end structure''
as that term is used in Sec. 393.106 of this title.
* * * * *
Hydraulic brake system. A system that uses hydraulic fluid as a
medium for transmitting force from a service brake control to the
service brake, and that may incorporate a brake power assist unit, or a
brake power unit.
* * * * *
Multi-piece windshield. A windshield consisting of two or more
windshield glazing surface areas.
Parking brake system. A mechanism designed to prevent the movement
of a stationary motor vehicle.
* * * * *
Side marker lamp (Intermediate). A lamp mounted on the side, on the
permanent structure of the motor vehicle that provides light to the
side to indicate the approximate middle of the vehicle, when the motor
vehicle is 9.14 meters (30 feet) or more in length.
Side Marker Lamps. Lamps mounted on the side, on the permanent
structure of the motor vehicle as near as practicable to the front and
rear of the vehicle, that provide light to the side to indicate the
overall length of the motor vehicle.
* * * * *
Split service brake system. A brake system consisting of two or
more subsystems actuated by a single control designed so that a
leakage-type failure of a pressure component in a single subsystem
(except structural failure of a housing that is common to two or more
subsystems) shall not impair the operation of any other subsystem.
* * * * *
Tow bar. A strut or column-like device temporarily attached between
the rear of a towing vehicle and the front of the vehicle being towed.
* * * * *
Trailer kingpin. A pin (with a flange on its lower end) which
extends vertically from the front of the underside of a semitrailer and
which locks into a fifth wheel.
* * * * *
Vacuum brake system. A system that uses a vacuum and atmospheric
pressure for transmitting a force from the driver control to the
service brake, not including a system that uses vacuum only to assist
the driver in applying muscular force to hydraulic or mechanical
components.
* * * * *
Windshield. The principal forward facing glazed surface provided
for forward vision in operating a motor vehicle.
* * * * *

[[Page 48027]]

? 8. Section 393.7 is amended by redesignating paragraphs (b)(1) through
(b)(6) as (b)(17) through (b)(23), adding new paragraphs (b)(1) through
(b)(16), revising newly redesignated (b)(17) and adding paragraphs
(c)(7) and (c)(8) to read as follows:

Sec. 393.7 Matters incorporated by reference.

* * * * *
(b)(1) Auxiliary Upper Beam Lamps, Society of Automotive Engineers
(SAE) J581, July 2004, incorporation by reference approved for Sec.
393.24(b).
(2) Front Fog Lamp, SAE J583, August 2004, incorporation by
reference approved for Sec. 393.24(b).
(3) Stop Lamps for Use on Motor Vehicles Less Than 2032 mm in
Overall Width, SAE J586, March 2000, incorporation by reference
approved for Sec. 393.25(c).
(4) Stop Lamps and Front- and Rear-Turn Signal Lamps for Use on
Motor Vehicles 2032 mm or more in Overall Width, SAE J2261, January
2002, incorporated by reference approved for Sec. 393.25 (c).
(5) Tail Lamps (Rear Position Lamps) for Use on Motor Vehicles Less
Than 2032 mm in Overall Width, SAE J585, March 2000, incorporation by
reference approved for Sec. 393.25(c).
(6) Tail Lamps (Rear Position Lamps) for Use on Vehicles 2032 mm or
More in Overall Width, SAE J2040, March 2002, incorporation by
reference approved for Sec. 393.25(c).
(7) Turn Signal Lamps for Use on Motor Vehicles Less Than 2032 mm
in Overall Width, SAE J588, March 2000, incorporation by reference
approved for Sec. 393.25(c).
(8) Sidemarker Lamps for Use on Road Vehicles Less Than 2032 mm in
Overall Width, SAE J592, August 2000, incorporation by reference
approved for Sec. 393.25(c).
(9) Directional Flashing Optical Warning Devices for Authorized
Emergency, Maintenance, and Service Vehicles, SAE J595, January 2005,
incorporation by reference approved for Sec. 393.25(e).
(10) Optical Warning Devices for Authorized Emergency, Maintenance,
and Service Vehicles, SAE J845, May 1997, incorporation by reference
approved for Sec. 393.25(e).
(11) Gaseous Discharge Warning Lamp for Authorized Emergency,
Maintenance, and Service Vehicles, SAE J1318, May 1998, incorporation
by reference approved for Sec. 393.25(e).
(12) Reflex Reflectors, SAE J594, December 2003, incorporation by
reference approved for Sec. 393.26(c).
(13) Standard Specification for Retroreflective Sheeting for
Traffic Control, American Society of Testing and Materials, ASTM D
4956-04, 2004, incorporation by reference approved for Sec. 393.26(c).
(14) Automobile, Truck, Truck-Tractor, Trailer, and Motor Coach
Wiring, SAE J1292, October 1981, incorporated by reference approved for
Sec. 393.28.
(15) Long Stroke Air Brake Actuator Marking, SAE J1817, July 2001,
incorporation by reference approved for Sec. 393.47(e).
(16) American National Standard for Safety Glazing Materials for
Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land
Highways-Safety Standard, SAE Z26.1-1996, August 1997, incorporation by
reference approved for Sec. 393.62(d).
(17) Specification for Sound Level Meters, American National
Standards Institute, S1.4-1983, incorporation by reference approved for
Sec. 393.94(c).
* * * * *
(c) Availability. The materials incorporated by reference are
available as follows:
* * * * *
(7) Standards of the Society of Automotive Engineers (SAE).
Information and copies may be obtained by writing to: Society of
Automotive Engineers, Inc., 400 Commonwealth Drive, Warrendale,
Pennsylvania 15096.
(8) Standards of the American National Standards Institute (ANSI).
Information and copies may be obtained by writing to: American National
Standards Institute, 25 West 43rd Street, New York, New York 10036.
* * * * *

? 9. The title of subpart B is revised to read as follows:

Subpart B--Lamps, Reflective Devices, and Electrical Wiring

? 10. Section 393.9 is revised to read as follows:

Sec. 393.9 Lamps operable, prohibition of obstructions of lamps and
reflectors.

(a) All lamps required by this subpart shall be capable of being
operated at all times. This paragraph shall not be construed to require
that any auxiliary or additional lamp be capable of operating at all times.
(b) Lamps and reflective devices/material required by this subpart
must not be obscured by the tailboard, or by any part of the load, or
its covering by dirt, or other added vehicle or work equipment, or
otherwise. Exception: The conspicuity treatments on the front end
protection devices may be obscured by part of the load being transported.

? 11. Section 393.11 is revised to read as follows:

Sec. 393.11 Lamps and reflective devices.

(a)(1) Lamps and reflex reflectors. Table 1 specifies the
requirements for lamps, reflective devices and associated equipment by
the type of commercial motor vehicle. The diagrams in this section
illustrate the position of the lamps, reflective devices and associated
equipment specified in Table 1. All commercial motor vehicles
manufactured on or after December 25, 1968, must, at a minimum, meet
the applicable requirements of 49 CFR 571.108 (FMVSS No. 108) in effect
at the time of manufacture of the vehicle. Commercial motor vehicles
manufactured before December 25, 1968, must, at a minimum, meet the
requirements of subpart B of part 393 in effect at the time of manufacture.
(2) Exceptions: Pole trailers and trailer converter dollies must
meet the part 393 requirements for lamps, reflective devices and
electrical equipment in effect at the time of manufacture. Trailers
which are equipped with conspicuity material which meets the
requirements of Sec. 393.11(b) are not required to be equipped with
the reflex reflectors listed in Table 1 if--
(i) The conspicuity material is placed at the locations where
reflex reflectors are required by Table 1; and
(ii) The conspicuity material when installed on the motor vehicle
meets the visibility requirements for the reflex reflectors.
(b) Conspicuity Systems. Each trailer of 2,032 mm (80 inches) or
more overall width, and with a GVWR over 4,536 kg (10,000 pounds),
manufactured on or after December 1, 1993, except pole trailers and
trailers designed exclusively for living or office use, shall be
equipped with either retroreflective sheeting that meets the
requirements of FMVSS No. 108 (S5.7.1), reflex reflectors that meet the
requirements FMVSS No. 108 (S5.7.2), or a combination of
retroreflective sheeting and reflex reflectors that meet the
requirements of FMVSS No. 108 (S5.7.3). The conspicuity system shall be
installed and located as specified in FMVSS No. 108 [S5.7.1.4 (for
retroreflective sheeting), S5.7.2.2 (for reflex reflectors), S5.7.3
(for a combination of sheeting and reflectors)] and have certification
and markings as required by S5.7.1.5 (for retroreflective tape) and
S5.7.2.3 (for reflex reflectors).
(c) Prohibition on the use of amber stop lamps and tail lamps. No
commercial motor vehicle may be equipped with an amber stop lamp, a
tail lamp, or other lamp which is

[[Page 48028]]

optically combined with an amber stop lamp or tail lamp.
(d) Prohibition on the use of auxiliary lamps that supplement the
identification lamps. No commercial motor vehicle may be equipped with
lamps that are in a horizontal line with the required identification
lamps unless those lamps are required by this regulation.

Table 1.--Required Lamps and Reflectors on Commercial Motor Vehicles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Height above
the road
surface in
millimeters
(mm) (with
Item on the vehicle Quantity Color Location Position English units Vehicles for which the devices
in parenthesis) are required
measured from
the center of
the lamp at
curb weight
--------------------------------------------------------------------------------------------------------------------------------------------------------
Headlamps........................ 2 White.................. Front.......... On the front at Not less than A, B, C
the same 559 mm (22
height, with inches) nor
an equal more than
number at each 1,372 mm (54
side of the inches).
vertical
center line as
far apart as
practicable.
Turn signal (front). See 2 Amber.................. At or near the One on each Not less than A, B, C
footnotes #2 and 12. front. side of the 381 mm (15
vertical inches) nor
centerline at more than
the same 2,108 mm (83
height and as inches).
far apart as
practicable.
Identification lamps (front). See 3 Amber.................. Front.......... As close as All three on B, C
footnote #1. practicable to the same level
the top of the as close as
vehicle, at practicable to
the same the top of the
height, and as motor vehicle.
close as
practicable to
the vertical
centerline of
the vehicle
(or the
vertical
centerline of
the cab where
different from
the centerline
of the
vehicle) with
lamp centers
spaced not
less than 152
mm (6 inches)
or more than
305 mm (12
inches) apart.
Alternatively,
the front
lamps may be
located as
close as
practicable to
the top of the
cab.
Tail lamps. See footnotes < greek- 2 Red.................... Rear........... One lamp on Both on the A, B, C, D, E, F, G, H
i>5 and 11. each side of same level
the vertical between 381 mm
centerline at (15 inches)
the same and 1,829 mm
height and as (72 inches).
far apart as
practicable.
--------------------------------------------------------------------------------------------------------------------------------------------------------

[[Page 48029]]

Table 1.--Required Lamps and Reflectors on Commercial Motor Vehicles
--------------------------------------------------------------------------------------------------------------------------------------------------------
Height above
the road
surface in
millimeters
(mm) (with
Item on the vehicle Quantity Color Location Position English units Vehicles for which the devices
in parenthesis) are required
measured from
the center of
the lamp at
curb weight
--------------------------------------------------------------------------------------------------------------------------------------------------------
Stop lamps. See footnotes < greek- 2 Red.................... Rear........... One lamp on Both on the A, B, C, D, E, F, G
i>5 and 13. each side of same level
the vertical between 381 mm
centerline at (15 inches)
the same and 1,829 mm
height and as (72 inches).
far apart as
practicable.
Clearance lamps. See footnotes 2 Amber.................. One on each One on each Both on the B, C, D, G, H
#8, 9, 10, 15 & 17. side of the side of the same level as
front of the vertical high as
vehicle. centerline to practicable.
indicate
overall width.
2 Red.................... One on each One on each Both on the B, D, G, H
side of the side of the same level as
rear of the vertical high as
vehicle. centerline to practicable.
indicate
overall width.
Reflex reflector, intermediate 2 Amber.................. One on each At or near the Between 381 mm A, B, D, F, G
(side). side. midpoint (15inches) and
between the 1,524 (60
front and rear inches).
side marker
lamps, if the
length of the
vehicle is
more than
9,144 mm (30
feet).
Reflex reflector (rear). See 2 Red.................... Rear........... One on each Both on the A, B, C, D, E, F, G
footnotes #5, 6, and 8. side of the same level,
vertical between 381 mm
centerline, as (15 inches)
far apart as and 1,524 mm
practicable (60 inches).
and at the
same height.
Reflex reflector (rear side)..... 2 Red.................... One on each As far to the Both on the A, B, D, F, G
side (rear). rear as same level,
practicable. between 381 mm
(15 inches)
and 1,524 mm
(60 inches).
Reflex reflector (front side). 2 Amber.................. One on each As far to the Between 381 mm A, B, C, D, F, G
See footnote #16. side (front). front as (15 inches)
practicable. and 1,524 mm
(60 inches).
License plate lamp (rear). See 1 White.................. At rear license No requirements A, B, C, D, F, G
footnote #11. plate to
illuminate the
plate from the
top or sides.
Side marker lamp (front). See 2 Amber.................. One on each As far to the Not less than A, B, C, D, F
footnote #16. side. front as 381 mm (15
practicable. inches).

[[Page 48030]]

Side marker lamp intermediate.... 2 Amber.................. One on each At or near the Not less tan A, B, D, F, G
side. midpoint 381 mm (15
between the inches).
front and rear
side marker
lamps, if the
length of the
vehicle is
more than
9,144 mm (30
feet).
Side marker lamp (rear). See 2 Red.................... One on each As far to the Not less than A, B, D, F, G
footnotes #4 and 8. side. rear as 381 mm (15
practicable. inches), and
on the rear of
trailers not
more than
1,524 mm (60
inches).
Turn signal (rear). See footnotes 2 Amber or red........... Rear........... One lamp on Both on the A, B, C, D, E, F, G
#5 and 12. each side of same level,
the vertical between 381 mm
centerline as (15 inches)
far apart as and 2,108 mm
practicable. (83 inches).
Identification lamp (rear). See 3 Red.................... Rear........... One as close as All three on B, D, G
footnotes #3, 7, and 15. practicable to the same level
the vertical as close as
centerline. practicable to
One on each the top of the
side with lamp vehicle.
centers spaced
not less than
152 mm (6
inches) or
more than 305
mm (12 inches)
apart.
Vehicular hazard warning signal 2 Amber.................. Front.......... One lamp on Both on the A, B, C
flasher lamps. See footnotes each side of same level,
#5 and 12. the vertical between 381 mm
centerline, as (15 inches)
far apart as and 2,108 mm
practicable. (83 inches).
2 Amber or red........... Rear........... One lamp on Both on the A, B, C, D, E, F, G
each side of same level,
the vertical between 381 mm
centerline, as (15 inches)
far apart as and 2,108 mm
practicable. (83 inches).
Backup lamp. See footnote < greek- 1 or 2 White.................. Rear........... Rear........... No requirement. A, B, C
i>14.
Parking lamp..................... 2 Amber or white......... Front.......... One lamp on Both on the A
each side of same level,
the vertical between 381 mm
centerline, as (15 inches)
far apart as and 2,108 mm
practicable. (83 inches).
--------------------------------------------------------------------------------------------------------------------------------------------------------
Legend: Types of commercial motor vehicles shown in the last column of Table 1.
A. Buses and trucks less than 2,032 mm (80 inches) in overall width.
B. Buses and trucks 2,032 mm (80 inches) or more in overall width.
C. Truck tractors.
D. Semitrailers and full trailers 2,032 mm (80 inches) or more in overall width except converter dollies.
E. Converter dolly.
F. Semitrailers and full trailers less than 2,032 mm (80 inches) in overall width.
G. Pole trailers.
H. Projecting loads.

[[Page 48031]]

Note: Lamps and reflectors may be combined as permitted by Sec. 393.22 and S5.4 of 49 CFR 571.108, Equipment combinations.
Footnote--1 Identification lamps may be mounted on the vertical centerline of the cab where different from the centerline of the vehicle, except where
the cab is not more than 42 inches wide at the front roofline, then a single lamp at the center of the cab shall be deemed to comply with the
requirements for identification lamps. No part of the identification lamps or their mountings may extend below the top of the vehicle windshield.
Footnote--2 Unless the turn signals on the front are so constructed (double-faced) and located as to be visible to passing drivers, two turn signals are
required on the rear of the truck tractor, one at each side as far apart as practicable.
Footnote--3 The identification lamps need not be visible or lighted if obscured by a vehicle in the same combination.
Footnote--4 Any semitrailer or full trailer manufactured on or after March 1, 1979, shall be equipped with rear side-marker lamps at a height of not
less than 381 mm (15 inches), and on the rear of trailers not more than 1,524 mm (60 inches) above the road surface, as measured from the center of
the lamp on the vehicle at curb weight.
Footnote--5 Each converter dolly, when towed singly by another vehicle and not as part of a full trailer, shall be equipped with one stop lamp, one tail
lamp, and two reflectors (one on each side of the vertical centerline, as far apart as practicable) on the rear. Each converter dolly shall be
equipped with rear turn signals and vehicular hazard warning signal flasher lamps when towed singly by another vehicle and not as part of a full
trailer, if the converter dolly obscures the turn signals at the rear of the towing vehicle.
Footnote--6 Pole trailers shall be equipped with two reflex reflectors on the rear, one on each side of the vertical centerline as far apart as
practicable, to indicate the extreme width of the trailer.
Footnote--7 Pole trailers, when towed by motor vehicles with rear identification lamps meeting the requirements of Sec. 393.11 and mounted at a height
greater than the load being transported on the pole trailer, are not required to have rear identification lamps.
Footnote--8 Pole trailers shall have on the rearmost support for the load: (1) two front clearance lamps, one on each side of the vehicle, both on the
same level and as high as practicable to indicate the overall width of the pole trailer; (2) two rear clearance lamps, one on each side of the
vehicle, both on the same level and as high as practicable to indicate the overall width of the pole trailer; (3) two rear side marker lamps, one on
each side of the vehicle, both on the same level, not less than 375 mm (15 inches) above the road surface; (4) two rear reflex reflectors, one on each
side, both on the same level, not less than 375 mm (15 inches) above the road surface to indicate maximum width of the pole trailer; and (5) one red
reflector on each side of the rearmost support for the load. Lamps and reflectors may be combined as allowed in Sec. 393.22.
Footnote--9 Any motor vehicle transporting a load which extends more than 102 mm (4 inches) beyond the overall width of the motor vehicle shall be
equipped with the following lamps in addition to other required lamps when operated during the hours when headlamps are required to be used.
(1) The foremost edge of that portion of the load which projects beyond the side of the vehicle shall be marked (at its outermost extremity) with an
amber lamp visible from the front and side.
(2) The rearmost edge of that portion of the load which projects beyond the side of the vehicle shall be marked (at its outermost extremity) with a red
lamp visible from the rear and side.
(3) If the projecting load does not measure more than 914 mm (3 feet) from front to rear, it shall be marked with an amber lamp visible from the front,
both sides, and rear, except that if the projection is located at or near the rear it shall be marked by a red lamp visible from front, side, and
rear.
Footnote--10 Projections beyond rear of motor vehicles. Motor vehicles transporting loads which extend more than 1,219 mm (4 feet) beyond the rear of
the motor vehicle, or which have tailboards or tailgates extending more than 1,219 mm (4 feet) beyond the body, shall have these projections marked as
follows when the vehicle is operated during the hours when headlamps are required to be used:
(1) On each side of the projecting load, one red side marker lamp, visible from the side, located so as to indicate maximum overhang.
(2) On the rear of the projecting load, two red lamps, visible from the rear, one at each side; and two red reflectors visible from the rear, one at
each side, located so as to indicate maximum width.
Footnote--11 To be illuminated when tractor headlamps are illuminated.
Footnote--12 Every bus, truck, and truck tractor shall be equipped with a signaling system that, in addition to signaling turning movements, shall have
a switch or combination of switches that will cause the two front turn signals and the two rear signals to flash simultaneously as a vehicular traffic
signal warning, required by Sec. 392-22(a). The system shall be capable of flashing simultaneously with the ignition of the vehicle on or off.
Footnote--13 To be actuated upon application of service brakes.
Footnote--14 Backup lamp required to operate when bus, truck, or truck tractor is in reverse.
Footnote--15
(1) For the purposes of Section 393.11, the term ``overall width'' refers to the nominal design dimension of the widest part of the vehicle, exclusive
of the signal lamps, marker lamps, outside rearview mirrors, flexible fender extensions, and mud flaps.
(2) Clearance lamps may be mounted at a location other than on the front and rear if necessary to indicate the overall width of a vehicle, or for
protection from damage during normal operation of the vehicle.
(3) On a trailer, the front clearance lamps may be mounted at a height below the extreme height if mounting at the extreme height results in the lamps
failing to mark the overall width of the trailer.
(4) On a truck tractor, clearance lamps mounted on the cab may be located to indicate the width of the cab, rather than the width of the vehicle.
(5) When the rear identification lamps are mounted at the extreme height of a vehicle, rear clearance lamps are not required to be located as close as
practicable to the top of the vehicle.
Footnote--16 A trailer subject to this part that is less than 1829 mm (6 feet) in overall length, including the trailer tongue, need not be equipped
with front side marker lamps and front side reflex reflectors.
Footnote--17 A boat trailer subject to this part whose overall width is 2032 mm (80 inches) or more need not be equipped with both front and rear
clearance lamps provided an amber (front) and red (rear) clearance lamp is located at or near the midpoint on each side so as to indicate its extreme
width.

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[[Page 48044]]

? 12. Section 393.17 is amended by revising the illustrations at the end
of the section to read as follows:

Sec. 393.17 Lamp and reflectors--combinations in driveway-towaway
operation.

* * * * *
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? 13. Section 393.19 is revised to read as follows:

Sec. 393.19 Hazard warning signals.

The hazard warning signal operating unit on each commercial motor
vehicle shall operate independently of the ignition or equivalent
switch, and when activated, cause all turn signals required by Sec.
393.11 to flash simultaneously.

Sec. 393.20 [Removed]

? 14. Section 393.20 is removed and reserved.

? 15. Section 393.23 is revised to read as follows:

Sec. 393.23 Power supply for lamps.

All required lamps must be powered by the electrical system of the
motor vehicle with the exception of battery powered lamps used on
projecting loads.

? 16. Section 393.24 is revised to read as follows:

Sec. 393.24 Requirements for head lamps, auxiliary driving lamps and
front fog lamps.

(a) Headlamps. Every bus, truck and truck tractor shall be equipped
with headlamps as required by Sec. 393.11(a). The headlamps shall
provide an upper and lower beam distribution of light, selectable at
the driver's will and be steady-burning. The headlamps shall be marked
in accordance with FMVSS No. 108. Auxiliary driving lamps and/or front
fog lamps may not be used to satisfy the requirements of this paragraph.
(b) Auxiliary driving lamps and front fog lamps. Commercial motor
vehicles may be equipped with auxiliary driving lamps and/or front fog
lamps for use in conjunction with, but not in lieu of the required
headlamps. Auxiliary driving lamps shall meet SAE Standard J581
Auxiliary Upper Beam Lamps, July 2004, and front fog lamps shall meet
SAE Standard J583 Front Fog Lamp, August 2004. (See Sec. 393.7 for
information on the incorporation by reference and availability of these
documents.)
(c) Mounting. Headlamps shall be mounted and aimable in accordance
with FMVSS No. 108. Auxiliary driving

[[Page 48047]]

lamps and front fog lamps shall be mounted so that the beams are
aimable and the mounting shall prevent the aim of the lighting device
from being disturbed while the vehicle is operating on public roads.
(d) Aiming. Headlamps, auxiliary driving lamps and front fog lamps
shall be aimed to meet the aiming specifications in FMVSS No. 108 (49
CFR 571.108), SAE J581, and SAE J583, respectively.

? 17. Section 393.25 is revised to read as follows:

Sec. 393.25 Requirements for lamps other than head lamps.

(a) Mounting. All lamps shall be securely mounted on a rigid part
of the vehicle. Temporary lamps must be securely mounted to the load
and are not required to be mounted to a permanent part of the vehicle.
(b) Visibility. Each lamp shall be located so that it meets the
visibility requirements specified by FMVSS No. 108 in effect at the
time of manufacture of the vehicle. Vehicles which were not subject to
FMVSS No. 108 at the time of manufacture shall have each lamp located
so that it meets the visibility requirements specified in the SAE
standards listed in paragraph (c) of this section. If motor vehicle
equipment (e.g., mirrors, snow plows, wrecker booms, backhoes, and
winches) prevents compliance with this paragraph by any required lamp,
an auxiliary lamp or device meeting the requirements of this paragraph
shall be provided. This shall not be construed to apply to lamps on one
unit which are obscured by another unit of a combination of vehicles.
(c) Specifications. All required lamps (except marker lamps on
projecting loads, lamps which are temporarily attached to vehicles
transported in driveaway-towaway operations, and lamps on converter
dollies and pole trailers) on vehicles manufactured on or after
December 25, 1968, shall, at a minimum, meet the applicable
requirements of FMVSS No. 108 in effect on the date of manufacture of
the vehicle. Marker lamps on projecting loads, all lamps which are
temporarily attached to vehicles transported in driveaway-towaway
operations, and all lamps on converter dollies and pole trailers must
meet the following applicable SAE standards: J586--Stop Lamps for Use
on Motor Vehicles Less Than 2032 mm in Overall Width, March 2000; J2261
Stop Lamps and Front- and Rear-Turn Signal Lamps for Use on Motor
Vehicles 2032 mm or More in Overall Width, January 2002; J585--Tail
Lamps (Rear Position Lamps) for Use on Motor Vehicles Less Than 2032 mm
in Overall Width, March 2000; J588--Turn Signal Lamps for Use on Motor
Vehicles Less Than 2032 mm in Overall Width, March 2000; J2040--Tail
Lamps (Rear Position Lamps) for Use on Vehicles 2032 mm or More in
Overall Width, March 2002; J592--Sidemarker Lamps for Use on Road
Vehicles Less Than 2032 mm in Overall Width, August 2000. (See Sec.
393.7 for information on the incorporation by reference and
availability of these documents.)
(d) (Reserved)
(e) Lamps to be steady-burning. All exterior lamps (both required
lamps and any additional lamps) shall be steady-burning with the
exception of turn signal lamps; hazard warning signal lamps; school bus
warning lamps; amber warning lamps or flashing warning lamps on tow
trucks and commercial motor vehicles transporting oversized loads; and
warning lamps on emergency and service vehicles authorized by State or
local authorities. Lamps combined into the same shell or housing with a
turn signal are not required to be steady burning while the turn signal
is in use. Amber warning lamps must meet SAE J845--Optical Warning
Devices for Authorized Emergency, Maintenance and Service Vehicles, May
1997. Amber flashing warning lamps must meet SAE J595--Directional
Flashing Optical Warning Devices for Authorized Emergency, Maintenance
and Service Vehicles, January 2005. Amber gaseous discharge warning
lamps must meet SAE J1318 Gaseous Discharge Warning Lamp for Authorized
Emergency, Maintenance, and Service Vehicles, May 1998. (See Sec.
393.7(b) for information on the incorporation by reference and
availability of these documents.)
(f) Stop lamp operation. The stop lamps on each vehicle shall be
activated upon application of the service brakes. The stop lamps are
not required to be activated when the emergency feature of the trailer
brakes is used or when the stop lamp is optically combined with the
turn signal and the turn signal is in use.

? 18. Section 393.26 is amended by revising paragraphs (a), (b), (c), and
(d) introductory text to read as follows:

Sec. 393.26 Requirements for reflex reflectors.

(a) Mounting. Reflex reflectors shall be mounted at the locations
required by Sec. 393.11. In the case of motor vehicles so constructed
that requirement for a 381 mm (15-inch) minimum height above the road
surface is not practical, the reflectors shall be mounted as close as
practicable to the required mounting height range. All permanent reflex
reflectors shall be securely mounted on a rigid part of the vehicle.
Temporary reflectors on projecting loads must be securely mounted to
the load and are not required to be permanently mounted to a part of
the vehicle. Temporary reflex reflectors on vehicles transported in
driveaway-towaway operations must be firmly attached.
(b) Specifications. All required reflex reflectors (except reflex
reflectors on projecting loads, vehicles transported in a driveaway-
towaway operation, converter dollies and pole trailers) on vehicles
manufactured on or after December 25, 1968, shall meet the applicable
requirements of FMVSS No. 108 in effect on the date of manufacture of
the vehicle. Reflex reflectors on projecting loads, vehicles
transported in a driveaway-towaway operation, and all reflex reflectors
on converter dollies and pole trailers must conform to SAE J594--Reflex
Reflectors, December 2003.
(c) Substitute material for side reflex reflectors. Reflective
material conforming to ASTM D 4956-04, Standard Specification for
Retroreflective Sheeting for Traffic Control, may be used in lieu of
reflex reflectors if the material as used on the vehicle, meets the
performance standards in either Table I of SAE J594 or Table IA of SAE
J594--Reflex Reflectors, December 2003. (See Sec. 393.7(b) for
information on the incorporation by reference and availability of these
documents.)
(d) Use of additional retroreflective surfaces. Additional
retroreflective surfaces may be used in conjunction with, but not in
lieu of the reflex reflectors required in subpart B of part 393, and
the substitute material for side reflex reflectors allowed by paragraph
(c) of this section, provided:
* * * * *

Sec. 393.27 [Removed]

? 18a. Section 393.27 is removed and reserved.
? 19. Section 393.28 is revised to read as follows:

Sec. 393.28 Wiring systems.

Electrical wiring shall be installed and maintained to conform to
SAE J1292--Automobile, Truck, Truck-Tractor, Trailer, and Motor Coach
Wiring, October 1981, except the jumper cable plug and receptacle need
not conform to SAE J560. The reference to SAE J1292 shall not be
construed to require circuit protection on trailers. (See Sec.
393.7(b) for information on the incorporation by reference and
availability of this document.)

[[Page 48048]]

Sec. 393.29 [Removed]

? 19a. Section 393.29 is removed and reserved.

? 20. Sections 393.31, 393.32, and 393.33 are removed and reserved.

? 21. Section 393.40 is revised to read as follows:

Sec. 393.40 Required brake systems.

(a) Each commercial motor vehicle must have brakes adequate to stop
and hold the vehicle or combination of motor vehicles. Each commercial
motor vehicle must meet the applicable service, parking, and emergency
brake system requirements provided in this section.
(b) Service brakes. (1) Hydraulic brake systems. Motor vehicles
equipped with hydraulic brake systems and manufactured on or after
September 2, 1983, must, at a minimum, have a service brake system that
meets the requirements of FMVSS No. 105 in effect on the date of
manufacture. Motor vehicles which were not subject to FMVSS No. 105 on
the date of manufacture must have a service brake system that meets the
applicable requirements of Sec. Sec. 393.42, 393.48, 393.49, 393.51,
and 393.52 of this subpart.
(2) Air brake systems. Buses, trucks and truck-tractors equipped
with air brake systems and manufactured on or after March 1, 1975, and
trailers manufactured on or after January 1, 1975, must, at a minimum,
have a service brake system that meets the requirements of FMVSS No.
121 in effect on the date of manufacture. Motor vehicles which were not
subject to FMVSS No. 121 on the date of manufacture must have a service
brake system that meets the applicable requirements of Sec. Sec.
393.42, 393.48, 393.49, 393.51, and 393.52 of this subpart.
(3) Vacuum brake systems. Motor vehicles equipped with vacuum brake
systems must have a service brake system that meets the applicable
requirements of Sec. Sec. 393.42, 393.48, 393.49, 393.51, and 393.52
of this subpart.
(4) Electric brake systems. Motor vehicles equipped with electric
brake systems must have a service brake system that meets the
applicable requirements of Sec. Sec. 393.42, 393.48, 393.49 and 393.52
of this subpart.
(c) Parking brakes. Each commercial motor vehicle must be equipped
with a parking brake system that meets the applicable requirements of
Sec. 393.41.
(d) Emergency brakes--partial failure of service brakes.
(1) Hydraulic brake systems. Motor vehicles manufactured on or
after September 2, 1983, and equipped with a split service brake system
must, at a minimum, meet the partial failure requirements of FMVSS No.
105 in effect on the date of manufacture.
(2) Air brake systems. Buses, trucks and truck tractors
manufactured on or after March 1, 1975, and trailers manufactured on or
after January 1, 1975, must be equipped with an emergency brake system
which, at a minumum, meets the requirements of FMVSS No. 121 in effect
on the date of manufacture.
(3) Vehicles not subject to FMVSS Nos. 105 and 121 on the date of
manufacture. Buses, trucks and truck tractors not subject to FMVSS Nos.
105 or 121 on the date of manufacture must meet the requirements of
Sec. 393.40(e). Trailers not subject to FMVSS No. 121 at the time of
manufacture must meet the requirements of Sec. 393.43.
(e) Emergency brakes, vehicles manufactured on or after July 1,
1973. (1) A bus, truck, truck tractor, or a combination of motor
vehicles manufactured on or after July 1, 1973, and not covered under
paragraphs (d)(1) or (d)(2) of this section, must have an emergency
brake system which consists of emergency features of the service brake
system or an emergency system separate from the service brake system.
The emergency brake system must meet the applicable requirements of
Sec. Sec. 393.43 and 393.52.
(2) A control by which the driver applies the emergency brake
system must be located so that the driver can operate it from the
normal seating position while restrained by any seat belts with which
the vehicle is equipped. The emergency brake control may be combined
with either the service brake control or the parking brake control.
However, all three controls may not be combined.
(f) Interconnected systems. (1) If the brake systems required by
Sec. 393.40(a) are interconnected in any way, they must be designed,
constructed, and maintained so that in the event of a failure of any
part of the operating mechanism of one or more of the systems (except
the service brake actuation pedal or valve), the motor vehicle will
have operative brakes and, for vehicles manufactured on or after July
1, 1973, be capable of meeting the requirements of Sec. 393.52(b).
(2) A motor vehicle to which the requirements of FMVSS No. 105
(S5.1.2), dealing with partial failure of the service brake, applied at
the time of manufacture meets the requirements of Sec. 393.40(f)(1) if
the motor vehicle is maintained in conformity with FMVSS No. 105 and
the motor vehicle is capable of meeting the requirements of Sec.
393.52(b), except in the case of a structural failure of the brake
master cylinder body.
(3) A bus is considered to meet the requirements of Sec.
393.40(f)(1) if it meets the requirements of Sec. 393.44 and Sec.
393.52(b).

? 22. Section 393.41 is revised to read as follows:

Sec. 393.41 Parking brake system.

(a) Hydraulic-braked vehicles manufactured on or after September 2,
1983. Each truck and bus (other than a school bus) with a GVWR of 4,536
kg (10,000 pounds) or less which is subject to this part and school
buses with a GVWR greater than 4,536 kg (10,000 pounds) shall be
equipped with a parking brake system as required by FMVSS No. 571.105
(S5.2) in effect at the time of manufacture. The parking brake shall be
capable of holding the vehicle or combination of vehicles stationary
under any condition of loading in which it is found on a public road
(free of ice and snow). Hydraulic-braked vehicles which were not
subject to the parking brake requirements of FMVSS No. 571.105 (S5.2)
must be equipped with a parking brake system that meets the
requirements of paragraph (c) of this section.
(b) Air-braked power units manufactured on or after March 1, 1975,
and air-braked trailers manufactured on or after January 1, 1975.
Each air-braked bus, truck and truck tractor manufactured on and
after March 1, 1975, and each air-braked trailer except an agricultural
commodity trailer, converter dolly, heavy hauler trailer or pulpwood
trailer, shall be equipped with a parking brake system as required by
FMVSS No. 121 (S5.6) in effect at the time of manufacture. The parking
brake shall be capable of holding the vehicle or combination of
vehicles stationary under any condition of loading in which it is found
on a public road (free of ice and snow). An agricultural commodity
trailer, heavy hauler or pulpwood trailer shall carry sufficient
chocking blocks to prevent movement when parked.
(c) Vehicles not subject to FMVSS Nos. 105 and 121 on the date of
manufacture. (1) Each singly driven motor vehicle not subject to
parking brake requirements of FMVSS Nos. 105 or 121 at the time of
manufacturer, and every combination of motor vehicles must be equipped
with a parking brake system adequate to hold the vehicle or combination
on any grade on which it is operated, under any condition of

[[Page 48049]]

loading in which it is found on a public road (free of ice and snow).
(2) The parking brake system shall, at all times, be capable of
being applied by either the driver's muscular effort or by spring
action. If other energy is used to apply the parking brake, there must
be an accumulation of that energy isolated from any common source and
used exclusively for the operation of the parking brake.
Exception: This paragraph shall not be applicable to air-applied,
mechanically-held parking brake systems which meet the parking brake
requirements of FMVSS No. 121 (S5.6). (3) The parking brake system
shall be held in the applied position by energy other than fluid
pressure, air pressure, or electric energy. The parking brake system
shall not be capable of being released unless adequate energy is
available to immediately reapply the parking brake with the required
effectiveness.

? 23. Section 393.42 is amended by revising the figure and revising
paragraph (b) to read as follows:

Sec. 393.42 Brakes required on all wheels.

* * * * *
(b) Exception. (1) Trucks or truck tractors having three or more
axles and manufactured before July 25, 1980, are not required to have
brakes on the front wheels. However, these vehicles must meet the
requirements of Sec. 393.52.
(2) Motor vehicles being towed in a driveaway-towaway operation are
not required to have operative brakes provided the combination of
vehicles meets the requirements of Sec. 393.52. This exception is not
applicable to:
(i) Any motor vehicle towed by means of a tow-bar when another
motor vehicle is full-mounted on the towed vehicle; and
(ii) Any combination of motor vehicles utilizing three or more
saddle-mounts.
(3) Any semitrailer or pole trailer (laden or unladen) with a gross
weight of 1,361 kg (3,000 pounds) or less which is subject to this part
is not required to be equipped with brakes if the axle weight of the
towed vehicle does not exceed 40 percent of the sum of the axle weights
of the towing vehicle.
(4) Any full trailer or four-wheel pole trailer (laden or unladen)
with a gross weight of 1,361 kg (3,000 pounds) or less which is subject
to this part is not required to be equipped with brakes if the sum of
the axle weights of the towed vehicle does not exceed 40 percent of the
sum of the axle weights of the towing vehicle.
(5) Brakes are not required on the steering axle of a three-axle
dolly which is steered by a co-driver.
(6) Loaded housemoving dollies, specialized trailers and dollies
used to transport industrial furnaces, reactors, and similar motor
vehicles are not required to be equipped with brakes, provided the
speed at which the combination of vehicles will be operated does not
exceed 32 km/hour (20 mph) and brakes on the combination of vehicles
are capable of stopping the combination within 12.2 meters (40 feet)
from the speed at which the vehicle is being operated or 32 km/hour (20
mph), whichever is less.
BILLING CODE 4910-EX-P

[[Page 48050]]
[GRAPHIC]
[TIFF OMITTED]
TR15AU05.020

BILLING CODE 4910-EX-C

? 24. Section 393.43 is amended by revising paragraphs (a), (d) and (f)
and by adding headings to paragraphs (b), (c), and (e) to read as follows:

Sec. 393.43 Breakaway and emergency braking.

(a) Towing vehicle protection system. Every motor vehicle, if used
to tow a trailer equipped with brakes, shall be equipped with a means
for providing that in the case of a breakaway of the trailer, the
service brakes on the towing vehicle will be capable of stopping the
towing vehicle. For air braked towing units, the tractor protection
valve or similar device shall operate automatically when the air
pressure on the towing vehicle is between 138 kPa and 310 kPa (20 psi
and 45 psi).
(b) Emergency brake requirements, air brakes. * * *
(c) Emergency brake requirements, vacuum brakes. * * *
(d) Breakaway braking requirements for trailers. Every trailer
required to be equipped with brakes shall have brakes which apply
automatically and immediately upon breakaway from the towing vehicle.
With the exception of trailers having three or more axles, all brakes
with which the trailer is required to be equipped must be applied upon
breakaway from the towing vehicle. The brakes must remain in the
applied position for at least 15 minutes.
(e) Emergency valves. * * *
(f) Exception. The requirements of paragraphs (b), (c) and (d) of
this section shall not be applicable to commercial motor vehicles being
transported in driveaway-towaway operations.

? 25. Section 393.45 is revised to read as follows:

Sec. 393.45 Brake tubing and hoses; hose assemblies and end fittings.

(a) General construction requirements for tubing and hoses,
assemblies, and end fittings. All brake tubing and hoses, brake hose
assemblies, and brake hose end fittings must meet the applicable
requirements of FMVSS No. 106 (49 CFR 571.106).
(b) Brake tubing and hose installation. Brake tubing and hose must--

[[Page 48051]]

(1) Be long and flexible enough to accommodate without damage all
normal motions of the parts to which it is attached;
(2) Be secured against chaffing, kinking, or other mechanical
damage; and
(3) Be installed in a manner that prevents it from contacting the
vehicle's exhaust system or any other source of high temperatures.
(c) Nonmetallic brake tubing. Coiled nonmetallic brake tubing may
be used for connections between towed and towing motor vehicles or
between the frame of a towed vehicle and the unsprung subframe of an
adjustable axle of the motor vehicle if--
(1) The coiled tubing has a straight segment (pigtail) at each end
that is at least 51 mm (2 inches) in length and is encased in a spring
guard or similar device which prevents the tubing from kinking at the
fitting at which it is attached to the vehicle; and
(2) The spring guard or similar device has at least 51 mm (2
inches) of closed coils or similar surface at its interface with the
fitting and extends at least 38 mm (1\1/2\ inches) into the coiled
segment of the tubing from its straight segment.
(d) Brake tubing and hose connections. All connections for air,
vacuum, or hydraulic braking systems shall be installed so as to ensure
an attachment free of leaks, constrictions or other conditions which
would adversely affect the performance of the brake system.

Sec. 393.46 [Removed]

? 26. Section 393.46 is removed and reserved.

? 27. Section 393.47 is revised to read as follows:

Sec. 393.47 Brake actuators, slack adjusters, linings/pads and drums/
rotors.

(a) General requirements. Brake components must be constructed,
installed and maintained to prevent excessive fading and grabbing. The
means of attachment and physical characteristics must provide for safe
and reliable stopping of the commercial motor vehicle.
(b) Brake chambers. The service brake chambers and spring brake
chambers on each end of an axle must be the same size.
(c) Slack adjusters. The effective length of the slack adjuster on
each end of an axle must be the same.
(d) Linings and pads. The thickness of the brake linings or pads
shall meet the applicable requirements of this paragraph--
(1) Steering axle brakes. The brake lining/pad thickness on the
steering axle of a truck, truck-tractor or bus shall not be less than
4.8 mm (\3/16\ inch) at the shoe center for a shoe with a continuous
strip of lining; less than 6.4 mm (\1/4\ inch) at the shoe center for a
shoe with two pads; or worn to the wear indicator if the lining is so
marked, for air drum brakes. The steering axle brake lining/pad
thickness shall not be less than 3.2 mm (\1/8\ inch) for air disc
brakes, or 1.6 mm (\1/16\ inch) or less for hydraulic disc, drum and
electric brakes.
(2) Non-steering axle brakes. An air braked commercial motor
vehicle shall not be operated with brake lining/pad thickness less than
6.4 mm (\1/4\ inch) or to the wear indicator if the lining is so marked
(measured at the shoe center for drum brakes); or less than 3.2 mm (\1/
8\ inch) for disc brakes. Hydraulic or electric braked commercial motor
vehicles shall not be operated with a lining/pad thickness less than
1.6 mm (\1/16\ inch) (measured at the shoe center) for disc or drum brakes.
(e) Clamp and Roto-Chamber Brake Actuator Readjustment limits. The
pushrod travel for clamp and roto-chamber type actuators must be less
than 80 percent of the rated strokes listed in SAE J1817--Long Stroke
Air Brake Actuator Marking, July 2001 (See Sec. 393.7 (b) for
information on incorporation by reference and availability of this
document), or 80 percent of the rated stroke marked on the brake
chamber by the chamber manufacturer, or the readjustment limit marked
on the brake chamber by the chamber manufacturer. The pushrod travel
for Type 16 and 20 long stroke clamp type brake actuators must be less
than 51 mm (2 inches) or 80 percent of the rated stroke marked on the
brake chamber by the chamber manufacturer, or the readjustment limit
marked on the brake chamber by the chamber manufacturer.
(f) Wedge Brake Adjustment. The movement of the scribe mark on the
lining shall not exceed 1.6 mm (\1/16\ inch).
(g) Drums and rotors. The thickness of the drums or rotors shall
not be less than the limits established by the brake drum or rotor
manufacturer.

? 28. Section 393.48 is revised to read as follows:

Sec. 393.48 Brakes to be operative.

(a) General rule. Except as provided in paragraphs (b) and (c) of
this section, all brakes with which a commercial motor vehicle is
equipped must be operable at all times.
(b) Devices to reduce or remove front-wheel braking effort. A
commercial motor vehicle may be equipped with a device to reduce the
front wheel braking effort (or in the case of a three-axle truck or
truck tractor manufactured before March 1, 1975, a device to remove the
front-wheel braking effort) if that device meets the applicable
requirements of paragraphs (b)(1) and (2) of this section.
(1) Manually operated devices. Manually operated devices to reduce
or remove front-wheel braking effort may only be used on buses, trucks,
and truck tractors manufactured before March 1, 1975. Such devices must
not be used unless the vehicle is being operated under adverse
conditions such as wet, snowy, or icy roads.
(2) Automatic devices. Automatic devices must not reduce the front-
wheel braking force by more than 50 percent of the braking force
available when the automatic device is disconnected (regardless of
whether or not an antilock system failure has occurred on any axle).
The device must not be operable by the driver except upon application
of the control that activates the braking system. The device must not
be operable when the brake control application pressure exceeds 85 psig
(for vehicles equipped with air brakes) or 85 percent of the maximum
system pressure (for vehicles which are not equipped with air brakes).
(c) Exception. Paragraph (a) of this section does not apply to--
(1) A towed vehicle with disabling damage as defined in Sec. 390.5;
(2) A vehicle which is towed in a driveaway-towaway operation and
is included in the exemption to the requirement for brakes on all
wheels, Sec. 393.42(b);
(3) Unladen converter dollies with a gross weight of 1,361 kg
(3,000 lbs) or less, and manufactured prior to March 1, 1998;
(4) The steering axle of a three-axle dolly which is steered by a
co-driver;
(5) Loaded house moving dollies, specialized trailers and dollies
used to transport industrial furnaces, reactors, and similar motor
vehicles provided the speed at which the combination of vehicles will
be operated does not exceed 32 km/hour (20 mph) and brakes on the
combination of vehicles are capable of stopping the combination within
12.2 meters (40 feet) from the speed at which the vehicle is being
operated or 32 km/hour (20 mph), whichever is less.
(6) Raised lift axles. Brakes on lift axles need not be capable of
being operated while the lift axle is raised. However, brakes on lift
axles must be capable of being applied whenever the lift axle is
lowered and the tires contact the roadway.

[[Page 48052]]

? 29. Section 393.50 is revised to read as follows:

Sec. 393.50 Reservoirs required.

(a) Reservoir capacity for air-braked power units manufactured on
or after March 1, 1975, and air-braked trailers manufactured on or
after January 1, 1975. Buses, trucks, and truck-tractors manufactured
on or after March 1, 1975, and air-braked trailers manufactured on or
after January 1, 1975, must meet the reservoir requirements of FMVSS
No. 121, S5.1.2, in effect on the date of manufacture.
(b) Reservoir capacity for air-braked vehicles not subject to FMVSS
No. 121 on the date of manufacture and all vacuum braked vehicles. Each
motor vehicle using air or vacuum braking must have either reserve
capacity, or a reservoir, that would enable the driver to make a full
service brake application with the engine stopped without depleting the
air pressure or vacuum below 70 percent of that indicated by the air or
vacuum gauge immediately before the brake application is made. For the
purposes of this paragraph, a full service brake application means
depressing the brake pedal or treadle valve to the limit of its travel.
(c) Safeguarding of air and vacuum. Each service reservoir system
on a motor vehicle shall be protected against a loss of air pressure or
vacuum due to a failure or leakage in the system between the service
reservoir and the source of air pressure or vacuum, by check valves or
equivalent devices whose proper functioning can be checked without
disconnecting any air or vacuum line, or fitting.
(d) Drain valves for air braked vehicles. Each reservoir must have
a condensate drain valve that can be manually operated. Automatic
condensate drain valves may be used provided (1) they may be operated
manually, or (2) a manual means of draining the reservoirs is retained.

? 30. Section 393.51 is revised to read as follows:

Sec. 393.51 Warning signals, air pressure and vacuum gauges.

(a) General Rule. Every bus, truck and truck tractor, except as
provided in paragraph (f), must be equipped with a signal that provides
a warning to the driver when a failure occurs in the vehicle's service
brake system. The warning signal must meet the applicable requirements
of paragraphs (b), (c), (d) or (e) of this section.
(b) Hydraulic brakes. Vehicles manufactured on or after September
1, 1975, must meet the brake system indicator lamp requirements of
FMVSS No. 571.105 (S5.3) applicable to the vehicle on the date of
manufacture. Vehicles manufactured on or after July 1, 1973 but before
September 1, 1975, or to which FMVSS No. 571.105 was not applicable on
the date of manufacture, must have a warning signal which operates
before or upon application of the brakes in the event of a hydraulic-
type complete failure of a partial system. The signal must be either
visible within the driver's forward field of view or audible. The
signal must be continuous. (NOTE: FMVSS No. 105 was applicable to
trucks and buses from September 1, 1975 to October 12, 1976, and from
September 1, 1983, to the present. FMVSS No. 105 was not applicable to
trucks and buses manufactured between October 12, 1976, and September
1, 1983. Motor carriers have the option of equipping those vehicles to
meet either the indicator lamp requirements of FMVSS No. 105, or the
indicator lamp requirements specified in this paragraph for vehicles
which were not subject to FMVSS No. 105 on the date of manufacture.)
(c) Air brakes. A commercial motor vehicle (regardless of the date
of manufacture) equipped with service brakes activated by compressed
air (air brakes) or a commercial motor vehicle towing a vehicle with
service brakes activated by compressed air (air brakes) must be
equipped with a pressure gauge and a warning signal. Trucks, truck
tractors, and buses manufactured on or after March 1, 1975, must, at a
minimum, have a pressure gauge and a warning signal which meets the
requirements of FMVSS No. 121 (S5.1.4 for the pressure gauge and S5.1.5
for the warning signal) applicable to the vehicle on the date of
manufacture of the vehicle. Power units to which FMVSS No. 571.121 was
not applicable on the date of manufacture of the vehicle must be
equipped with--
(1) A pressure gauge, visible to a person seated in the normal
driving position, which indicates the air pressure (in kilopascals
(kPa) or pounds per square inch (psi)) available for braking; and
(2) A warning signal that is audible or visible to a person in the
normal driving position and provides a continuous warning to the driver
whenever the air pressure in the service reservoir system is at 379 kPa
(55 psi) and below, or one-half of the compressor governor cutout
pressure, whichever is less.
(d) Vacuum brakes. A commercial motor vehicle (regardless of the
date it was manufactured) having service brakes activated by vacuum or
a vehicle towing a vehicle having service brakes activated by vacuum
must be equipped with--
(1) A vacuum gauge, visible to a person seated in the normal
driving position, which indicates the vacuum (in millimeters or inches
of mercury) available for braking; and
(2) A warning signal that is audible or visible to a person in the
normal driving position and provides a continuous warning to the driver
whenever the vacuum in the vehicle's supply reservoir is less than 203
mm (8 inches) of mercury.
(e) Hydraulic brakes applied or assisted by air or vacuum. Each
vehicle equipped with hydraulically activated service brakes which are
applied or assisted by compressed air or vacuum, and to which FMVSS No.
105 was not applicable on the date of manufacture, must be equipped
with a warning signal that conforms to paragraph (b) of this section
for the hydraulic portion of the system; paragraph (c) of this section
for the air assist/air applied portion; or paragraph (d) of this
section for the vacuum assist/vacuum applied portion. This paragraph
shall not be construed as requiring air pressure gauges or vacuum
gauges, only warning signals.
(f) Exceptions. The rules in paragraphs (c), (d) and (e) of this
section do not apply to property carrying commercial motor vehicles
which have less than three axles and (1) were manufactured before July
1, 1973, and (2) have a manufacturer's gross vehicle weight rating less
than 4,536 kg (10,001 pounds).

? 31. Section 393.61 is revised to read as follows:

Sec. 393.61 Truck and truck tractor window construction.

Each truck and truck tractor (except trucks engaged in armored car
service) shall have at least one window on each side of the driver's
compartment. Each window must have a minimum area of 1,290 cm\2\ (200
in\2\) formed by a rectangle 33 cm by 45 cm (13 inches by 17\3/4\
inches). The maximum radius of the corner arcs shall not exceed 152 mm
(6 inches). The long axis of the rectangle shall not make an angle of
more than 45 degrees with the surface on which the unladen vehicle
stands. If the cab is designed with a folding door or doors or with
clear openings where doors or windows are customarily located, no
windows shall be required in those locations.

? 32. Section 393.62 is revised to read as follows:

Sec. 393.62 Emergency exits for buses.

(a) Buses manufactured on or after September 1, 1994. Each bus with a

[[Page 48053]]

GVWR of 4,536 kg (10,000 pounds) or less must meet the emergency exit
requirements of FMVSS No. 217 (S5.2.2.3) in effect on the date of
manufacture. Each bus with a GVWR of more than 4,536 kg (10,000 pounds)
must have emergency exits which meet the applicable emergency exit
requirements of FMVSS No. 217 (S5.2.2 or S5.2.3) in effect on the date
of manufacture.
(b) Buses manufactured on or after September 1, 1973, but before
September 1, 1994. (1) Each bus (including a school bus used in
interstate commerce for non-school bus operations) with a GVWR of more
than 4,536 kg (10,000 lbs) must meet the requirements of FMVSS No. 217,
S5.2.2 in effect on the date of manufacture.
(2) Each bus (including a school bus used in interstate commerce
for non-school bus operations) with a GVWR of 4,536 kg (10,000 lbs) or
less must meet the requirements of FMVSS No. 217, S5.2.2.3 in effect on
the date of manufacture.
(c) Buses manufactured before September 1, 1973. For each seated
passenger space provided, inclusive of the driver there shall be at
least 432 cm2 (67 square inches) of glazing if such glazing
is not contained in a push-out window; or, at least 432 cm2
(67 square inches) of free opening resulting from opening of a push-out
type window. No area shall be included in this minimum prescribed area
unless it will provide an unobstructed opening of at least 1,290
cm2 (200 in2) formed by a rectangle 33 cm by 45
cm (13 inches by 17\3/4\ inches). The maximum radius of the corner arcs
shall not exceed 152 mm (6 inches). The long axis of the rectangle
shall not make an angle of more than 45 degrees with the surface on
which the unladen vehicle stands. The area shall be measured either by
removal of the glazing if not of the push-out type, or of the movable
sash if of the push-out type. The exit must comply with paragraph (d)
of this section. Each side of the bus must have at least 40 percent of
emergency exit space required by this paragraph.
(d) Laminated safety glass/push-out window requirements for buses
manufactured before September 1, 1973. Emergency exit space used to
satisfy the requirements of paragraph (c) of this section must have
laminated safety glass or push-out windows designed and maintained to
yield outward to provide a free opening.
(1) Safety glass. Laminated safety glass must meet Test No. 25,
Egress, of American National Standard for Safety Glazing Materials for
Glazing Motor Vehicles and Motor Vehicle Equipment Operating on Land
Highways--Safety Standards ANSI/SAE Z26.1/96, August 1997. (See Sec.
393.7 (b) for information on incorporation by reference and
availability of this document.)
(2) Push-out windows. Each push-out window shall be releasable by
operating no more than two mechanisms and allow manual release of the
exit by a single occupant. For mechanisms which require rotary or
straight (parallel to the undisturbed exit surface) motions to operate
the exit, no more than 89 Newtons (20 pounds) of force shall be
required to release the exit. For exits which require a straight motion
perpendicular to the undisturbed exit surface, no more than 267 Newtons
(60 pounds) shall be required to release the exit.
(e) Emergency exit identification. Each bus and each school bus
used in interstate commerce for non-school bus operations, manufactured
on or after September 1, 1973, shall meet the applicable emergency exit
identification or marking requirements of FMVSS No. 217, S5.5, in
effect on the date of manufacture. The emergency exits and doors on all
buses (including school buses used in interstate commerce for non-
school bus operations) must be marked ``Emergency Exit'' or ``Emergency
Door'' followed by concise operating instructions describing each
motion necessary to unlatch or open the exit located within 152 mm (6
inches) of the release mechanism.
(f) Exception for the transportation of prisoners. The requirements
of this section do not apply to buses used exclusively for the
transportation of prisoners.

Sec. 393.63 [Removed]

? 33. Section 393.63 is removed and reserved.

? 34. Section 393.67 is amended by removing the footnote to paragraphs
(d) and (e); by revising the introductory text of paragraphs (a), (d),
and (e); and by revising paragraph (f)(2) to read as follows:

Sec. 393.67 Liquid fuel tanks.

(a) Application of the rules in this section. The rules in this
section apply to tanks containing or supplying fuel for the operation
of commercial motor vehicles or for the operation of auxiliary equipment
installed on, or used in connection with commercial motor vehicles.
* * * * *
(d) Liquid fuel tank tests. Each liquid fuel tank must be capable
of passing the tests specified in paragraphs (d)(1) and (2) of this
section. The specified tests are a measure of performance only.
Alternative procedures which assure that equipment meets the required
performance standards may be used.
* * * * *
(e) Side-mounted liquid fuel tank tests. Each side-mounted liquid
fuel tank must be capable of passing the tests specified in paragraphs
(e)(1) and (2) of this section and the test specified in paragraphs
(d)(1) and (2) of this section. The specified tests are a measure of
performance only. Alternative procedures which assure that equipment
meets the required performance criteria may be used.
* * * * *
(f) * * *
(2) The manufacturer's name on tanks manufactured on and after July
1, 1989, and means of identifying the facility at which the tank was
manufactured, and
* * * * *

? 35. Section 393.68 is added to part 393 and reads as follows:

Sec. 393.68 Compressed natural gas fuel containers.

(a) Applicability. The rules in this section apply to compressed
natural gas (CNG) fuel containers used for supplying fuel for the
operation of commercial motor vehicles or for the operation of
auxiliary equipment installed on, or used in connection with commercial
motor vehicles.
(b) CNG containers manufactured on or after March 26, 1995. Any
motor vehicle manufactured on or after March 26, 1995, and equipped
with a CNG fuel tank must meet the CNG container requirements of FMVSS
No. 304 (49 CFR 571.304) in effect at the time of manufacture of the
vehicle.
(c) Labeling. Each CNG fuel container shall be permanently labeled
in accordance with the requirements of FMVSS No. 304, S7.4.

? 36. Section 393.70 is amended by revising paragraph (d)(8) to read as
follows:

Sec. 393.70 Coupling devices and towing methods, except for
driveaway-towaway operation.

(d) * * *
(8)(i) When two safety devices, including two safety chains or
cables, are used and are attached to the towing vehicle at separate
points, the points of attachment on the towing vehicle shall be located
equally distant from, and on opposite sides of, the longitudinal
centerline of the towing vehicle.
(ii) Where two chains or cables are attached to the same point on
the towing vehicle, and where a bridle or a single chain or cable is
used, the point

[[Page 48054]]

of attachment must be on the longitudinal centerline or within 152 mm
(6 inches) to the right of the longitudinal centerline of the towing
vehicle.
(iii) A single safety device, other than a chain or cable, must
also be attached to the towing vehicle at a point on the longitudinal
centerline or within 152 mm (6 inches) to the right of the longitudinal
centerline of the towing vehicle.

? 37. Section 393.71 is amended by revising paragraphs (a)(2) and (g) and
by adding paragraph (b)(3):

Sec. 393.71 Coupling devices and towing methods, driveaway-towaway
operations.

(a) * * *
(2) No more than one tow-bar or ball-and-socket type coupling
device may be used in any combination.
* * * * *
(b) Carrying vehicles on towing vehicles, and multiple saddle-mounts.
* * * * *
(3) Saddle-mounted vehicles must be arranged such that the gross
weight of the vehicles is properly distributed to prevent undue
interference with the steering, braking, or maneuvering of the
combination of vehicles.
* * * * *
(g) Means required for towing. No motor vehicles or combination of
motor vehicles shall be towed in driveaway-towaway operations by means
other than a tow-bar, ball-and-socket type coupling device, saddle-
mount connections which meet the requirements of this section, or in
the case of a semi-trailer equipped with an upper coupler assembly, a
fifth-wheel meeting the requirements of Sec. 393.70.
* * * * *

? 38. Section 393.75 is amended by revising paragraph (e) to read as follows:

Sec. 393.75 Tires.

* * * * *
(e) A regrooved tire with a load-carrying capacity equal to or
greater than 2,232 kg (4,920 pounds) shall not be used on the front
wheels of any truck or truck tractor.
* * * * *

? 39. Section 393.78 is revised to read as follows:

Sec. 393.78 Windshield wiping and washing systems.

(a) Vehicles manufactured on or after December 25, 1968. Each bus,
truck, and truck-tractor manufactured on or after December 25, 1968,
must have a windshield wiping system that meets the requirements of
FMVSS No. 104 (S4.1) in effect on the date of manufacture. Each of
these vehicles must have a windshield washing system that meets the
requirements of FMVSS No. 104 (S4.2.2) in effect on the date of
manufacture.
(b) Vehicles manufactured between June 30, 1953, and December 24,
1968. Each truck, truck-tractor, and bus manufactured between June 30,
1953, and December 24, 1968, shall be equipped with a power-driven
windshield wiping system with at least two wiper blades, one on each
side of the centerline of the windshield. Motor vehicles which depend
upon vacuum to operate the windshield wipers, shall have the wiper
system constructed and maintained such that the performance of the
wipers will not be adversely affected by a change in the intake
manifold pressure.
(c) Driveaway-towaway operations. Windshield wiping and washing
systems need not be in working condition while a commercial motor
vehicle is being towed in a driveaway-towaway operation.

? 40. Section 393.79 is revised to read as follows:

Sec. 393.79 Windshield defrosting and defogging systems.

(a) Vehicles manufactured on or after December 25, 1968. Each bus,
truck, and truck-tractor manufactured on or after December 25, 1968,
must have a windshield defrosting and defogging system that meets the
requirements of FMVSS No. 103 in effect on the date of manufacture.
(b) Vehicles manufactured before December 25, 1968. Each bus,
truck, and truck-tractor shall be equipped with a means for preventing
the accumulation of ice, snow, frost, or condensation that could
obstruct the driver's view through the windshield while the vehicle is
being driven.

? 41. Section 393.82 is revised to read as follows:

Sec. 393.82 Speedometer.

Each bus, truck, and truck-tractor must be equipped with a
speedometer indicating vehicle speed in miles per hour and/or
kilometers per hour. The speedometer must be accurate to within plus or
minus 8 km/hr (5 mph) at a speed of 80 km/hr (50 mph).

? 42. Section 393.87 is revised to read as follows:

Sec. 393.87 Warning flags on projecting loads.

(a) Any commercial motor vehicle transporting a load which extends
beyond the sides by more than 102 mm (4 inches) or more than 1,219 mm
(4 feet) beyond the rear must have the extremities of the load marked
with red or orange fluorescent warning flags. Each warning flag must be
at least 457 mm (18 inches) square.
(b) Position of flags. There must be a single flag at the extreme
rear if the projecting load is two feet wide or less. Two warning flags
are required if the projecting load is wider than two feet. Flags must
be located to indicate maximum width of loads which extend beyond the
sides and/or rear of the vehicle.

Sec. 393.92 [Removed]

? 43. Section 393.92 is removed and reserved.

? 44. Section 393.94 is amended revising the section heading, by removing
paragraph (d) and the footnote to paragraph (c), and by revising
paragraphs (a) and (c)(4) to read as follows:

Sec. 393.94 Interior noise levels in power units.

(a) Applicability of this section. The interior noise level
requirements apply to all trucks, truck-tractors, and buses.
* * * * *
(c)(4) The sound level meters used to determine compliance with the
requirements of this section must meet the American National Standards
Institute ``Specification for Sound Level Meters,'' ANSI S1.4--1983.
(See Sec. 393.7(b) for information on the incorporation by reference
and availability of this document.)
* * * * *

? 45. Section 393.95 is amended by revising the introductory text; by
removing and reserving paragraphs (c), (h) and (i); and by revising
paragraphs (a), (b) and (f) to read as follows:

Sec. 393.95 Emergency equipment on all power units.

Each truck, truck tractor, and bus (except those towed in
driveaway-towaway operations) must be equipped as follows:
(a) Fire Extinguishers.
(1) Minimum ratings: (i) A power unit that is used to transport
hazardous materials in a quantity that requires placarding (See Sec.
177.823 of this title) must be equipped with a fire extinguisher having
an Underwriters' Laboratories rating of 10 B:C or more.
(ii) A power unit that is not used to transport hazardous materials
must be equipped with either:
(A) A fire extinguisher having an Underwriters' Laboratories rating
of 5 B:C or more; or
(B) Two fire extinguishers, each of which has an Underwriters'
Laboratories rating of 4 B:C or more.

[[Page 48055]]

(2) Labeling and marking. Each fire extinguisher required by this
section must be labeled or marked by the manufacturer with its
Underwriters' Laboratories rating.
(3) Visual Indicators. The fire extinguisher must be designed,
constructed, and maintained to permit visual determination of whether
it is fully charged.
(4) Condition, location, and mounting. The fire extinguisher(s)
must be filled and located so that it is readily accessible for use.
The extinguisher(s) must be securely mounted to prevent sliding,
rolling, or vertical movement relative to the motor vehicle.
(5) Extinguishing agents. The fire extinguisher must use an
extinguishing agent that does not need protection from freezing.
Extinguishing agents must comply with the toxicity provisions of the
Environmental Protection Agency's Significant New Alternatives Policy
(SNAP) regulations under 40 CFR Part 82, Subpart G.
(b) Spare fuses. Power units for which fuses are needed to operate
any required parts and accessories must have at least one spare fuse
for each type/size of fuse needed for those parts and accessories.
* * * * *
(f) Warning devices for stopped vehicles. Except as provided in
paragraph (g) of this section, one of the following options must be used:
(1) Three bidirectional emergency reflective triangles that conform
to the requirements of Federal Motor Vehicle Safety Standard No. 125,
Sec. 571.125 of this title; or
(2) At least 6 fusees or 3 liquid-burning flares. The vehicle must
have as many additional fusees or liquid-burning flares as are
necessary to satisfy the requirements of Sec. 392.22.
(3) Other warning devices may be used in addition to, but not in
lieu of, the required warning devices, provided those warning devices
do not decrease the effectiveness of the required warning devices.
* * * * *

? 46. Section 393.201 is amended by removing paragraph (f) and by
revising paragraphs (a) and (d) to read as follows:

Sec. 393.201 Frames.

(a) The frame or chassis of each commercial motor vehicle shall not
be cracked, loose, sagging or broken.
* * * * *
(d) Parts and accessories shall not be welded to the frame or
chassis of a commercial motor vehicle except in accordance with the
vehicle manufacturer's recommendations. Any welded repair of the frame
must also be in accordance with the vehicle manufacturer's
recommendations.
* * * * *

? 47. Section 393.207 is amended by adding paragraph (g) to read as
follows:

Sec. 393.207 Suspension systems.

* * * * *
(g) Air suspension exhaust controls. The air suspension exhaust
controls must not have the capability to exhaust air from the
suspension system of one axle of a two-axle air suspension trailer
unless the controls are either located on the trailer, or the power
unit and trailer combination are not capable of traveling at a speed
greater than 10 miles per hour while the air is exhausted from the
suspension system. This paragraph shall not be construed to prohibit--
(1) Devices that could exhaust air from both axle systems
simultaneously; or
(2) Lift axles on multi-axle units.

? 48. Section 393.209 is amended by revising paragraph (b) and the first
sentence of paragraph (d) to read as follows:

Sec. 393.209 Steering wheel systems.

* * * * *
(b) Steering wheel lash. (1) The steering wheel lash shall not
exceed the following parameters:

------------------------------------------------------------------------
Manual steering Power steering
Steering wheel diameter system system
------------------------------------------------------------------------
406 mm or less (16 inches or 51 mm (2 inches).... 108 mm (4\1/4\
less). inches).
457 mm (18 inches).......... 57 mm (2\1/4\ 121 mm (4\3/4\
inches). inches).
483 mm (19 inches).......... 60 mm (2\3/8\ 127 mm (5 inches).
inches).
508 mm (20 inches).......... 64 mm (2\1/2\ 133 mm (5\1/4\
inches). inches).
533 mm (21 inches).......... 67 mm (2\5/8\ 140 mm (5\1/2\
inches). inches).
559 mm (22 inches).......... 70 mm (2\3/4\ 146 mm (5\3/4\
inches). inches).
------------------------------------------------------------------------

(2) For steering wheel diameters not listed in paragraph (b)(1) of
this section the steering wheel lash shall not exceed 14 degrees
angular rotation for manual steering systems, and 30 degrees angular
rotation for power steering systems.
* * * * *
(d) Steering system. Universal joints and ball-and-socket joints
shall not be worn, faulty or repaired by welding. * * *
* * * * *
[FR Doc. 05-14259 Filed 8-12-05; 8:45 am]
BILLING CODE 4910-EX-P

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