[Federal Register Volume 70, Number 156 (Monday, August 15, 2005)]
[Rules and Regulations]
[Pages 48008-48055]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 05-14259]



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Part III





Department of Transportation





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Federal Motor Carrier Safety Administration



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49 CFR Parts 390, 392, and 393



Parts and Accessories Necessary for Safe Operation; General Amendments; 
Final Rule

  Federal Register / Vol. 70, No. 156 / Monday, August 15, 2005 / Rules 
and Regulations  

[[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


Parts and Accessories Necessary for Safe Operation; General 
Amendments

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.

0
In consideration of the foregoing, FMCSA amends title 49, Code of 
Federal Regulations, subchapter B, chapter III, as follows:

PART 390--[AMENDED]

0
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.

0
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]

0
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.

0
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]

0
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.

0
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.

0
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]]


0
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.
* * * * *

0
9. The title of subpart B is revised to read as follows:

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

0
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.

0
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 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 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 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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0
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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[[Page 48045]]


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0
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]

0
14. Section 393.20 is removed and reserved.

0
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.

0
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.

0
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.
0
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]

0
18a. Section 393.27 is removed and reserved.
0
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]

0
19a. Section 393.29 is removed and reserved.

0
20. Sections 393.31, 393.32, and 393.33 are removed and reserved.

0
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).
0
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.

0
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.
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[[Page 48050]]

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0
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.

0
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]

0
26. Section 393.46 is removed and reserved.

0
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.

0
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]]


0
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.

0
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).

0
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.

0
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]

0
33. Section 393.63 is removed and reserved.
0
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
* * * * *

0
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.

0
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.

0
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.
* * * * *

0
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.
* * * * *

0
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.

0
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.

0
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).

0
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]

0
43. Section 393.92 is removed and reserved.
0
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.)
* * * * *

0
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.
* * * * *

0
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.
* * * * *

0
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.

0
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