Parts and Accessories Necessary for Safe Operation; General Amendments

DEPARTMENT OF TRANSPORTATION

Federal Highway Administration

49 CFR Parts 390, 392, and 393

[FHWA Docket No. MC-97-5]

RIN 2125-AD40

Parts and Accessories Necessary for Safe Operation; General

Amendments

AGENCY: Federal Highway Administration (FHWA), DOT.

ACTION: Notice of proposed rulemaking (NPRM); request for comments.

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SUMMARY: The FHWA is proposing to amend 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 571); and codify certain FHWA 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 consistent with

the President's Regulatory Reinvention Initiative and furthers the

FHWA's ongoing Zero-Base Regulatory Review in that it proposes to make

many sections more concise, easier to understand and more performance

oriented.

DATES: Written comments must be received on or before June 13, 1997.

ADDRESSES: Signed, written comments should refer to the docket number

that appears at the top of this document and must be submitted to the

Docket Clerk, U.S. DOT Dockets, Room PL-401, 400 Seventh Street, SW.,

Washington, DC 20590-0001. All comments received will be available for

examination at the above address between 10 a.m. and 5 p.m., e.t.,

Monday through Friday, except Federal holidays. Those desiring

notification of receipt of comments must include a self-addressed,

stamped envelope or postcard.

FOR FURTHER INFORMATION CONTACT: Mr. Larry W. Minor, Office of Motor

Carrier Research and Standards, HCS-10, (202) 366-4009; or Mr. Charles

E. Medalen, Office of the Chief Counsel, HCC-20, (202) 366-1354,

Federal Highway Administration, 400 Seventh Street, SW., Washington, DC

20590. Office hours are from 7:45 a.m. to 4:15 p.m., e.t., Monday

through Friday, except Federal holidays.

SUPPLEMENTARY INFORMATION:

Background

On December 7, 1988, the FHWA published a final rule on parts and

accessories necessary for safe operation (53 FR 49380). The final rule

included amendments to the requirements for lamps and reflective

devices, brake systems, fuel systems, frames and frame assemblies,

suspension systems, steering systems, and axle assemblies. This action

was taken to implement sections 206 and 210 of the Motor Carrier Safety

Act of 1984 (the Act) (49 U.S.C. 31136 and 31142) and to ensure that

commercial motor vehicles are equipped with all parts and accessories

considered necessary for safe operation. Since the publication of the

final rule, the FHWA has received numerous petitions for rulemaking and

requests for interpretation of the requirements of part 393 which have

raised the need for additional amendments to clarify several provisions

of the 1988 final rule. 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, has 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.

Proposed Amendments

Section-by-Section Discussion of the Proposed Amendments

Section 390.5--Definition of Driveaway-Towaway Operation

Parts 393 and 396 of the FMCSRs include several exceptions for

driveaway-towaway operations. 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 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). It has become apparent that

this definition does not provide sufficient guidance in identifying the

specific types of vehicle operations covered. The FHWA has received

numerous requests for clarification of the applicability of the

driveaway-towaway exceptions to construction equipment and storage

trailers. Typically storage trailers are parked for several weeks to

several months at a construction site and moved occasionally from one

site to another. Construction equipment is also moved only occasionally

from site to site. Therefore, the FHWA is proposing to limit the

definition of a driveaway-towaway operation to motor vehicles being

transported (1) between a vehicle manufacturer and a dealership or a

purchaser, (2) between a dealership, or other entity selling or leasing

the vehicle, and a purchaser or lessee, (3) to a maintenance/repair

facility for the repair of disabling damage (as defined in Sec. 390.5),

or (4) by means of a saddle-mount. In addition, the driveaway-towaway

exception would only apply to those cases in which the motor vehicles

are not transporting cargo or passengers. The proposed revision is

intended to reduce confusion.

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Section 392.33--Obscured Lamps or Reflectors

The FHWA is proposing to amend 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). Since 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. The FHWA

recognizes that this temporary obstruction of the reflective material

cannot be avoided in many cases and does not believe that it would be

appropriate to penalize motor carriers.

Section 393.1--Scope of the Rules of This Part

The FHWA is proposing a revision of 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 the

applicability of the provisions in part 393 when a lightweight vehicle

is used to tow a trailer in interstate commerce. 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 unless placardable quantities of hazardous

materials are being transported. 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 (FMVSSs) 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

The FHWA is proposing to amend 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 would

be revised. The definition of bus would be removed from Sec. 393.5 in

favor of the definition found in Sec. 390.5.

The proposed definitions of brake systems and components would make

the brake requirements under subpart C of part 393 easier to understand

and enforce.

The proposed 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, the 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.) Since the NHTSA has considered air-over-hydraulic brake

systems subject to FMVSS No. 121 for more than 20 years, the FHWA's

adoption of the NHTSA's definitions should not affect the applicability

of the brake requirements under part 393.

The proposed definition of a boat trailer is the same as that

contained under 49 CFR 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.'' The FHWA proposes to include this definition because

Sec. 393.11 contains requirements for lamps and reflectors on boat

trailers.

The FHWA is proposing to replace its definition of ``emergency

brake system'' with the NHTSA's definition for ``emergency brake.''

This change will ensure consistency between the FHWA's brake

regulations covering motor carriers and the NHTSA's regulations

covering manufacturers.

The agency is proposing that NHTSA's FMVSS No. 105 definition of a

split service brake system be included under Sec. 393.5. The inclusion

of this definition would help 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

would be added to Sec. 393.5 to support other proposed revisions to the

brake system requirements of part 393. Since 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, several of the proposed revisions to

subpart C would specifically reference electric and vacuum brakes. The

proposed definitions would prevent confusion or misunderstandings on

the part of motor carriers and enforcement officials.

With regard to the definition of a chassis, the agency is proposing

to delete 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.

It is proposed that the definition of a clearance lamp be replaced

with the Society of Automotive Engineers' (SAE) definition (Glossary of

Automotive Terms, SP-750, February 1988). 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, the FHWA proposes to replace the

reference to paragraph (1) of Sec. 177.834 with a reference to

paragraph (l). The reference to paragraph (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. The FHWA would adopt the

SAE's definition to ensure that definitions in part 393 are consistent

with industry definitions.

To clarify the applicability of parking brake requirements, the

agency is proposing that the definition of a parking brake system in

Sec. 393.5 be revised to replace the term ``vehicle'' with ``motor

vehicle,'' which is defined in Sec. 390.5.

The agency proposes that the definitions of ``side marker lamp

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(intermediate)'' and ``side marker lamp'' be revised 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 the FHWA is proposing to revise 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, the 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

FHWA and the NHTSA, the FHWA is proposing to amend its definition of a

heavy hauler trailer to exclude container chassis trailers.

The FHWA is proposing to add a definition of intermodal shipping

container to the FMCSRs to clarify the use of the term in

Sec. 393.100(e). The definition would be the same as the definition of

``container'' under Sec. 390.52.

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

The FHWA is proposing to revise the title of subpart B to read

``Lamps, Reflective Devices, and Electrical Wiring.'' The new title

would be 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 requirements for the electrical wiring for

several vehicle systems in addition to the lamps required by FMVSS No.

108.

Section 393.9--Lamps Operable

The agency is proposing to amend 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. The FHWA 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. The FHWA proposes to codify

this regulatory guidance.

Section 393.11--Lighting Devices and Reflectors

The FHWA is proposing that the title of Sec. 393.11 be revised to

read ``Lamps and reflective devices'' to maintain consistency between

the proposed title for subpart B and Sec. 393.11. The FHWA is also

proposing that motor vehicles manufactured on or after December 25,

1968, be required to meet the requirements of FMVSS No. 108 in effect

at the time of manufacture or a later, higher, standard. 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.

The NHTSA's FMVSS No. 108 became effective on December 25, 1968, so

manufacturers have been required to meet these requirements since that

date. The FHWA's reference to March 7, 1989, under Sec. 393.11 is

therefore inappropriate. Since vehicles manufactured between December

25, 1968, and March 7, 1989, were originally manufactured to meet FMVSS

No. 108, motor carriers who have maintained lamps and reflectors in the

required locations for these older vehicles would not be affected by

the proposed revision.

In addition, the FHWA is proposing to revise 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, the 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 gross vehicle

weight rating (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.

The NHTSA 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, the FHWA is proposing the addition

of detailed language under Sec. 393.11. The FHWA would cross-reference

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.

The FHWA notes that during the NHTSA 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 the FHWA. 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 proposed rulemaking concerning

rear impact guards (57 FR 252, January 3, 1992)] would be even

lower). Therefore, the final rule requires retroreflective material

to be applied to the horizontal device, instead of the vertical ones

as proposed. 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, the FHWA 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 proposed cross-reference to the NHTSA conspicuity requirements

includes a reference to the specific paragraphs within FMVSS No. 108

concerning the locations for the conspicuity treatments. The proposal

does not, however, include an exemption to the requirement that motor

carriers maintain the conspicuity

[[Page 18173]]

material on the rear underride device. The agency requests comments

from motor carriers on the durability of the conspicuity material

located on the horizontal member of the rear underride protection

devices. Commenters are asked to identify the specific types of

trailers and operating conditions that they believe are associated with

the durability problems cited in addition to providing color

photographs of the damaged conspicuity materials.

The FHWA published an advance notice of proposed rulemaking

concerning the possibility of retrofitting trailers manufactured prior

to December 1, 1993, with the red and white reflective material (59 FR

2811, January 19, 1994). On August 6, 1996, the FHWA announced that it

would issue a notice of proposed rulemaking to require motor carriers

to retrofit their trailers with conspicuity material (61 FR 40781).

Since the issue of retrofitting is being addressed under FHWA Docket

No. MC-94-1, comments on that subject will not be considered in this

rulemaking.

In addition to providing explicit guidance on trailer conspicuity,

the FHWA proposes to amend Sec. 393.11 to codify certain regulatory

guidance on 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 the FHWA, the

NHTSA indicated that a combination amber turn signal and tail lamp is

implicitly prohibited by FMVSS No. 108.

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

combination amber turn signal and taillamp is implicitly prohibited

by Standard No. 108.

The FHWA agrees that motorists are not used 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 that the proposed prohibition does not conflict with

FMVSS No. 108, the FHWA reviewed the 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, the NHTSA may review that

determination and, if clearly erroneous, inform the manufacturer of its

views.

Since Sec. 393.11 cross-references FMVSS No. 108, the FHWA'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 the

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 needed 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. The FHWA is not aware of any vehicle manufacturers that use

amber stop lamps or tail lamps as standard equipment. Consequently, the

proposed 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, the FHWA is

proposing amendments to footnotes 4 through 10 to address

inconsistencies with other sections of subpart B to part 393. In

addition, the agency is proposing to correct 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 would be covered under a new footnote

17.

The listings for reflex reflectors (front side) and side marker

lamps (front) are being 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 would be covered under a

new footnote 16.

The FHWA is proposing to remove 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 (SAE) recommended

practice Clearance, Side Marker, and Identification Lamps, (SAE J592e,

July 1972) which provides photometric standards. These standards cover

geometric 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. Since side marker lamps

which meet the minimum standards contained in SAE J592e generally are

not visible in the rearview mirror, the agency is proposing to amend

footnote 4.

The FHWA is proposing editorial changes to footnotes 5 through 8 to

improve the manner in which the requirements are presented. For

instance, in footnote 5 the change would make 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 would remove the requirements that

projecting loads be equipped with

[[Page 18174]]

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 would be 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

The FHWA proposes to change the wording of the diagrams which

illustrate the requirements of Sec. 393.17. The diagrams incorrectly

reference Secs. 393.25(e) and 393.26(d) and would be amended to

reference Sec. 393.11, which covers the color of exterior lamps and

reflective devices.

Section 393.19--Requirements for Turn Signaling Systems

The FHWA is proposing to revise 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, the FHWA would adopt

the NHTSA standard.

Section 393.20--Clearance Lamps to Indicate Extreme Width and Height

The FHWA is proposing to remove 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 would be 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

The FHWA is proposing to amend 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 would be required to be powered through the electrical

system of the commercial motor vehicle. The title of Sec. 393.23 would

be revised to read ``Power supply for lamps'' and the reference to red

liquid-burning lanterns would be removed as obsolete.

Section 393.24--Requirements for Headlamps and Auxiliary Road Lighting

Lamps

The FHWA is proposing to amend 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.'' The FHWA would incorporate by reference

SAE standards J581 Auxiliary Driving Lamps, January 1995, and J583

Front Fog Lamps, June 1993, 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 should be specified to ensure that the use of such devices

does not decrease safety.

A new paragraph is being proposed 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. The FHWA proposes 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, would be

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 proposed 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,

the FHWA is proposing to revise Sec. 393.25 in its entirety. Section

393.25(a) would provide a concise description of the mounting

requirements for lamps. Paragraph (b) Visibility, would provide

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. The FHWA determined that Sec. 392.30

duplicated State and local regulations and removed that requirement on

November 23, 1994 (59 FR 60319). Also, the FHWA 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 would be required to meet the

visibility requirements specified in the SAE standards proposed for

incorporation by reference under Sec. 393.25(c).

The FHWA is proposing to delete Sec. 393.25(d), 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 have 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)

would correct this inconsistency.

The agency is proposing to amend Sec. 393.25(e), Lighting devices

to be steady-burning, and Sec. 393.25(f), Stop lamp operation, to

provide more concise statements of the requirements of each. The FHWA

is proposing to allow exceptions for the use of amber warning lamps

which meet SAE J595, Flashing Warning Lamps for Authorized Emergency,

Maintenance and Service Vehicles, January 1990, SAE J845, 360 Degree

Warning Lamp for Authorized Emergency, Maintenance and Service

Vehicles, March 1992, or SAE J1318 Gaseous Discharge Warning Lamp for

Authorized Emergency, Maintenance, and Service Vehicles, April 1986.

Only Class 2 and Class 3, 360 degree warning lamps and gaseous

discharge warning lamps would be allowed. Class 1, 360-degree and

gaseous discharge warning lamps, the primary warning lamps for use on

authorized emergency vehicles responding to emergency situations, would

not be allowed. All of these SAE recommended practices would be

incorporated by reference. In determining the need for this proposal,

the FHWA notes that Class 2 and 3, 360-degree warning lamps and similar

non-steady burning lamps are used on many commercial motor vehicles

which

[[Page 18175]]

transport oversized loads, tow trucks, and certain utility company

vehicles. Adding these devices to the list of exceptions would prevent

confusion as to the applicability of Sec. 393.25(e).

The FHWA is proposing to revise Sec. 393.25(f) to eliminate a

regulatory inconsistency between Secs. 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, 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.

Since 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 proposed revision to Sec. 393.25(f)

would include 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 proposed amendments to Sec. 393.25, the FHWA is

proposing to revise Sec. 393.26 in its entirety. The agency would amend

Sec. 393.26(a) concerning the mounting of reflectors, to provide

guidelines comparable to those proposed for Sec. 393.25(a). Paragraph

(b) would be 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,

July 1995. The SAE recommended practice would be incorporated by

reference.

The current requirement for certification and marking under

Sec. 393.26(c) would be 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) D4956-90, 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 would have to meet the

geometric visibility requirements under SAE J594, Reflex Reflectors,

July 1995.

Paragraph (d) would be 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

The FHWA is proposing to incorporate 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 393.28 would be 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 proposed for incorporation would provide 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 would be removed.

The incorporation by reference would also remove certain design

restrictive language from Sec. 393.28(a)(5) concerning terminals or

splices above the fuel tank. The 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. The FHWA agrees with the

petitioners, however, that Sec. 393.28(a)(5) is still unnecessarily

restrictive. The proposed incorporation by reference would provide

criteria that effectively and safely address the issue of wiring around

the fuel system of commercial motor vehicles and resolve the

petitioners' concerns.

Subpart C--Brakes

Section 393.40--Required Brake Systems

The FHWA is proposing to revise Sec. 393.40 in its entirety to

present more clearly the requirements contained therein. Generally, all

vehicles which have been maintained to meet at least the manufacturing

standards applicable at the time of manufacture will not be affected by

the proposed revisions. Hydraulic braked and air braked vehicles would

be 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 would be 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, the FHWA 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, the FHWA 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

[[Page 18176]]

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. The FHWA has

since determined that additional changes are necessary. The current

language only covers air braked vehicles 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. The FHWA

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.

The agency is proposing to revise 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 would

be 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 would have to meet the requirements

currently found at Sec. 393.41 (b) and (c).

The proposed revisions to Sec. 393.41 would also address a petition

for rulemaking from International Transquip Industries, Incorporated

(ITI) asking the FHWA to clarify the applicable requirements for air-

applied, mechanically-held parking brakes. The petition is available

for review in the docket. The ITI 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, the 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 proposed revision of Sec. 393.41(b) would

include 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 proposing to revise 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,

the FHWA 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. The FHWA

believes Sec. 393.42 should be amended to make reference to the gross

weight. Trailers covered under the current reference to GVWR would be

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 proposed language would help to provide a

performance-based criteria 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, the NHTSA's Vehicle Research and Test Center (VRTC)

[[Page 18177]]

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-lane

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 bobtail proportioning valve (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, 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 FHWA 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 FHWA on November 17,

1993 (58 FR 60734) stated that Sec. 393.42(b)(3) is applicable to

unladen converter dollies, this NPRM would create 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. The FHWA is proposing to address 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.

The FHWA 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, will not be covered by the exception.

On the subject of housemoving dollies and similar vehicles designed

to transport extremely large and/or heavy loads, the FHWA is proposing

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.

The FHWA does not believe that safety would be 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 proposed exemption to the requirement for brakes on all wheels

would also cover 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).

The FHWA has no reason to 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 proposing to exempt 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

The FHWA is proposing to revise 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

[[Page 18178]]

the towing vehicle is between 138 kilopascals (kPa) and 310 kPa (20 psi

and 45 psi) would be 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.

The FHWA is proposing to revise 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 (58 FR 60734), the FHWA published regulatory guidance which

indicated that all brakes must be applied upon breakaway. This is

consistent with the FHWA's November 23, 1977, interpretation (42 FR

60078). Since 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. However, the FHWA believes that most

trailers would meet the proposed amendment to Sec. 393.43. The FHWA

specifically requests comments from trailer manufacturers concerning

this issue.

Sections 393.45 and 393.46--Brake Tubing and Hose

The FHWA is proposing to revise 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 hose

be designed and constructed in a manner that ensures proper, adequate,

and continued functioning of the tubing or hose. The tubing or hoses

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.

The FHWA would retain 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 (Secs. 393.45(a) and (b)) would be removed because the

cross-reference to FMVSS No. 106 addresses manufacturing aspects of

brake tubing and hoses.

With the exception of SAE J844--Nonmetallic Air Brake System

Tubing, the FHWA would eliminate the references to SAE standards on

brake hoses. Since brake hose manufacturers are required to meet all

applicable requirements under FMVSS No. 106, the other SAE references

are unnecessary. The FHWA would incorporate by reference SAE J844 (the

October 1994 version) for coiled nylon brake tubing because such tubing

is not required to meet S7.3.6 (length change), S7.3.10 (tensile

strength), and S7.3.11 (tensile strength of an assembly after immersion

in water) of FMVSS No. 106. Coiled nylon tubing is exempted from the

three specific tests through an FMVSS No. 106 cross-reference to

Sec. 393.45. The proposed incorporation by reference to SAE J844 would

preserve the current manufacturing standards under FMVSS No. 106 and

simplify the cross-referencing between FMVSS No. 106 and Sec. 393.45.

The requirements of Sec. 393.45(c) would be retained because they

cover aspects of brake hose and tubing installation that are not

covered in the FMVSSs and otherwise would not be adequately addressed

in the FMCSRs.

The FHWA would remove 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 proposed, the

current language of Sec. 393.45(d) would be obsolete.

The proposed changes to Sec. 393.45 would 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.

The FHWA believes the proposed cross-reference to FMVSS No. 106

would make 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. Also, the revision of Sec. 393.45 would

have the effect of exempting only coiled nylon tubing which meets SAE

J844 from the previously mentioned provisions of FMVSS No. 106.

On the subject of brake tubing and hose connections, the FHWA is

proposing 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 would be required to meet all applicable

requirements under FMVSS No. 106, as is currently the case. These

requirements, currently covered under Sec. 393.46, would be covered

under Sec. 393.45(e). Since the proposed language for Sec. 393.45

includes requirements concerning installation, connections and

attachments, Sec. 393.46 would be removed.

Section 393.47--Brake Lining

Section 393.47 would be revised to cover brake chambers, slack

adjusters, linings and pads, drums and rotors. Brake components would

be required to be constructed, installed, and maintained to prevent

excessive fading and grabbing. The means of attachment and physical

characteristics would have to 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 would be 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 would also be required to be the same. In addition,

minimum requirements on the thickness of linings or pads would be

specified.

With regard to linings and pads, the proposed criteria would 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 FHWA 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\

[[Page 18179]]

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.

The FHWA believes that these guidelines should be added to

Sec. 393.47 to help motor carriers identify steering axle brake linings

and pads that are excessively worn. Under a separate rulemaking the

FHWA will issue a proposal concerning the periodic inspection rule and

appendix G to subchapter B.

To address non-steering axle brake lining/pads, the FHWA would

incorporate into Sec. 393.47 the same criteria currently found in

appendix G.

Brake actuator readjustment limits would also be specified under

Sec. 393.47. The pushrod travel for clamp and roto-chamber type

actuators would be required to be less than 80 percent of the rated

strokes listed in SAE J1817--Long Stroke Air Brake Actuator Marking,

June 1991, 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) would be 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 would have to meet the limits established by the brake drum

or rotor manufacturer.

Section 393.48--Brakes to be Operative

The FHWA is proposing to revise Sec. 393.48 (a) and (b) to make the

requirements easier to understand. The revisions would provide a more

concise presentation of the requirements.

With regard to paragraph (c), the FHWA would explicitly address the

issue of unladen converter dollies and lift axles. Braking on unladen

converter dollies is covered extensively in discussion of the proposed

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

would have to 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 would be required to demonstrate that the brakes

on that axle are operable. The proposed revisions 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 would be addressed to ensure consistency between the proposed

revisions to Sec. 393.42 and Sec. 393.48.

Section 393.50--Reservoirs Required

Section 393.50 would be revised to provide a simpler and more

concise presentation 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, would have to 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.

The FHWA 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). The

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

The agency is proposing to revise 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,

would be 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,

would have to 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 proposed 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, the FHWA would insert 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. Since 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.

The FHWA has received numerous requests for interpretation from

motor carriers with vehicles manufactured during this period and not

equipped with a warning device. Through regulatory guidance, the FHWA

has 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 essentially

proposing to codify the regulatory guidance concerning warning devices

on these vehicles.

On the subject of air braked vehicles, the FHWA is proposing to

revise Sec. 393.51(c) to include reference to the

[[Page 18180]]

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 would also be included.

Vehicles which are not required to meet the requirements of FMVSS

No. 121 would have to 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, the FHWA is proposing to revise

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 would eliminate 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. The FHWA

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, the FHWA would retain 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 paragraph (c) or (d).

The FHWA notes that commercial motor vehicles equipped with air-

over-hydraulic brake systems are classified as air braked vehicles and,

as such, would be required to meet the applicable warning device and

pressure gauge requirements for air braked vehicles.

With regard to the proposed amendments to Sec. 393.51(e), the FHWA

specifically requests comments on the need for retaining the warning

device requirement for the air or vacuum portion of air- and vacuum-

assisted hydraulic brake systems. The FHWA also requests information

from vehicle manufacturers as to the number of commercial motor

vehicles manufactured annually with such brake systems or the last

model year for which they produced vehicles equipped with this type of

brake system.

Finally, the FHWA is proposing to reinstate one of the exemptions

that were 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 that were 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 only when transporting

hazardous materials in a quantity that requires placarding or when

towing another vehicle such that the gross combination weight rating

exceeds 4,536 kg (10,000 pounds).

Therefore, the FHWA believes that the exemption for certain two-

axle property-carrying vehicles should be reinstated but limited to

two-axle property-carrying vehicles manufactured before July 1, 1973.

Since the group of vehicles covered by the exemption represents a small

segment of the total population of vehicles that fall under the FHWA's

jurisdiction, and these vehicles have either reached, or will soon

reach the end of their service life, and these vehicles were previously

exempted, the proposed reinstatement should not reduce safety on the

highways.

The FHWA is not proposing to reinstate 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

Section 393.60--Glazing in Specified Openings

The FHWA is proposing that glazing material used in windshields,

windows and doors of commercial motor vehicles manufactured on or after

December 25, 1968, be required at a minimum to meet the requirements of

FMVSS No. 205 in effect on the date of manufacture of the vehicle. The

glazing material would be required to be marked accordingly. The cross-

reference to FMVSS No. 205 would replace the current reference to

Safety Code for Safety Glazing Materials for Glazing Motor Vehicles

Operating on Land Highways. Since FMVSS No. 205 incorporates this

publication by reference, the requirements for the glazing material

would not be affected.

Section 393.60 would also be revised to include a requirement that

each bus, truck, and truck-tractor be equipped with a windshield. Each

windshield or portion of a multi-piece windshield would be required to

be mounted using the full periphery of the glazing material.

With regard to coloring or tinting of windshields and side windows,

the FHWA would revise the current requirements to codify regulatory

guidance on this topic. Coloring or tinting of windshields and the

windows to the immediate right and left of the driver would be allowed

provided the parallel luminous transmittance through the colored or

tinted glazing is not less than 70 percent of the light at normal

incidence in those portions of the windshield or windows which are

marked as having a luminous transmittance of at least 70 percent.

The current reference to tinting applied at the time of manufacture

would be removed. The restrictions on tinting would be focused solely

on ensuring that the glazing material allows light transmittance at a

level requisite for driving visibility and not the regulation of when

the tinting is applied.

The agency is proposing to revise Sec. 393.60(c) concerning

restrictions on the use of vision-reducing matter on windshields. On

March 6, 1995, the FHWA granted a petition from the Commonwealth of

Kentucky, and Heavy Vehicle Electronic License Plate, Inc. (HELP)

requesting a waiver from the requirements of Sec. 393.60(c) to allow

mounting of an automatic vehicle identification transponder at the

upper border of the windshields of commercial motor vehicles ( 60 FR

12146). The waiver was necessary because Sec. 393.60(c) prohibits the

operation of a

[[Page 18181]]

commercial motor vehicle with vision-reducing matter covering any

portion of the windshield with certain exceptions for decals required

by law and affixed to the bottom of the windshield.

In evaluating the requests for waivers to Sec. 393.60(c), the FHWA

reviewed automotive engineering recommended practices, the NHTSA's

FMVSSs, and recent research concerning driver's field of view. The

agency also examined current commercial motor vehicle cab designs

related to placement of interior mirrors and sun visors which occupy

approximately the same space proposed for the transponder. Based upon

the information obtained from this review, the FHWA concluded that a

transponder mounted at the approximate center of the top of the

windshield would be extremely unlikely to create a situation

inconsistent with the safe operation of a commercial motor vehicle.

This location is well outside the area recommended for windshield wiper

sweep under the SAE recommended practice J198, Windshield Wiper

Systems--Trucks, Buses, and Multipurpose Vehicles, and the area

recommended for windshield defrosting under J342, Windshield Defrosting

Systems Performance Guidelines--Trucks, Buses, and Multipurpose

Vehicles. The findings of recent research reports on the subject also

suggested that the location of an object, such as a transponder device,

near the upper margin of a windshield is unlikely to have any effect on

a driver's ability to observe nearby objects, such as pedestrians.

For the reasons presented in the notice granting the waiver, the

agency is proposing to allow the installation of antennas,

transponders, and similar devices in the upper margin of windshields.

These devices could not be placed lower than 152 mm (6 inches) from the

upper edge of the windshield, must be outside the area swept by the

windshield wipers, and must be outside the driver's sight lines to the

road and highway signs or signals. The proposed amendment would codify

the March 6, 1995, waiver and help to promote the use of advanced

technologies to improve the efficiency and safety of operation of

commercial motor vehicles.

With regard to the current limitations on the placement of decals

and stickers at the bottom of the windshield, the FHWA would adopt a

performance-based requirement that decals required by law must not

obstruct the driver's view of the road, or traffic signs. Since the

decals in question are required by Federal or State law, the FHWA does

not believe it is necessary to retain the 11.4 cm (4-\1/2\ inch) -

restriction on the distance from the bottom of the windshield. It is

anticipated that the agencies responsible for specifying the location

of such decals will exercise discretion and limit the use of decals in

the windshield area.

Sections 393.61, 393.62, 393.63, 393.92--Window Construction and

Emergency Exits

Section 393.61 would be revised to cover only truck and truck

tractor window construction. Window construction for buses (or

emergency exits) would be covered under Sec. 393.62. The prohibitions

on window obstructions currently found at Sec. 393.62 would be

addressed along with the emergency exits requirements. The provisions

of Sec. 393.63 (Windows, markings) and Sec. 393.92 (Buses, marking

emergency doors) would also be covered under the revised rule on

emergency exits. Sections 393.63 and 393.92 would be removed.

In Sec. 393.61, the FHWA would remove 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, the FHWA would revise its cross-

references to FMVSS No. 217 so that motor carriers and enforcement

officials will have better guidance on the applicability of NHTSA's

recent amendments to those 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). The NHTSA final rule took effect September 1, 1994.

Further, in a separate notice, the NHTSA proposed allowing non-

school buses to meet either the non-school bus requirements or the new

upgraded school bus requirements (57 FR 49444, November 2, 1992). The

NHTSA issued the final rule on May 9, 1995 (60 FR 24562).

The FHWA has carefully reviewed the NHTSA rulemakings and

determined that the FMCSRs should be amended to address the November 2,

1992, and May 9, 1995, final rules. The FHWA is proposing to allow the

upgraded school bus emergency exit requirements on buses subject to the

FMCSRs so that motor carriers would be 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

proposed would be applicable. An example would be a small bus operated

by a private motor carrier of passengers.

For buses with a GVWR of more than 4,536 kg (10,000 pounds), the

FHWA would require 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 would incorporate NHTSA's final

rules.

For buses manufactured on or after September 1, 1973, but before

September 1, 1994, the FHWA is proposing 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 would have to meet the

requirements of FMVSS No. 217, S5.2.2.3, in effect on the date of

manufacture.

Section 393.62 would be 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, would have to 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) would have to 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, would be revised to provide requirements which are

easier to understand and enforce. These buses would have to 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

[[Page 18182]]

Standards Institute (ANSI), Safety Code for Safety Glazing Materials

for Glazing Motor Vehicles Operating on Land Highways, ANSI Z26.1-1990.

The FHWA would incorporate the ANSI document by reference.

With regard to push-out windows, the requirements would be revised

to adopt certain provisions of FMVSS No. 217. Each push-out window

would be 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).

The FHWA believes that the force requirements being proposed should

not present a problem for motor carriers and that older buses with

emergency exits that cannot meet these basic performance requirements

should have the emergency exit release mechanisms replaced. This

proposal 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, the FHWA would codify its regulatory guidance on buses used

for the transportation of prisoners. An exception to the emergency exit

requirements would be included for buses used exclusively for the

transportation of prisoners.

Subpart E--Fuel Systems

Section 393.67--Liquid Fuel Tanks

The FHWA proposes to revise 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 and the FHWA

believes the applicability statement of Sec. 393.67 should be amended

to be consistent with Sec. 393.65.

The FHWA also proposes to revise Sec. 393.67(d) and (e) to include

the information currently presented in a footnote to the section. 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, the FHWA proposes to correct 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. The FHWA intended that the date 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

The FHWA is proposing to create a new section to address

requirements for compressed natural gas (CNG) fuel containers. Section

393.68 would cross-reference 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.

The FHWA 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 the 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, the FHWA notes that a certain amount of

flexibility had been allowed such 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, the FHWA agrees that there

is a need to reexamine the requirement and eliminate any unnecessary

restrictions. To that end, the FHWA 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.

An amended rule that allows the attachment point to be offset no

more than a certain distance from the longitudinal centerline would

provide flexibility without adversely affecting the tracking of the

towed unit in the

[[Page 18183]]

event of a pintle hook failure. The FHWA 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 proposed change should not affect the safety of operation of the

vehicles.

The FHWA is proposing to allow 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. The

proposal would be 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 proposed 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.

The FHWA specifically requests comments on the following issues:

1. Although the petitioner did not specify a maximum offset

distance from the longitudinal centerline for the safety device

attachment point, the FHWA believes that a distance of 152 mm (6

inches) is consistent with the diagrams submitted by the petitioner.

Would allowing a 152 mm (6 inch) offset provide adequate flexibility to

motor carriers and trailer manufacturers without adversely affecting

the safety of operation of certain combination vehicles?

2. The petitioner believes that safety chains should be allowed to

be offset only to the right side of the longitudinal centerline in

order to prevent the towed vehicle from striking oncoming traffic on

undivided highways. In cases where a single safety device is used, and

it is not practical to attach it to a point at the longitudinal

centerline, should the offset be restricted to the right side, or

should it be permitted to be on either side?

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 requires clarification.

The FHWA 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 stability and

control would, at best, be comparable to a towing method which is

prohibited, the FHWA is proposing that Sec. 393.71(a)(2) be revised 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) would be

removed.

To improve the consistency between Sections 393.70 and 393.71, the

FHWA is proposing to amend 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

Secs. 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 Secs. 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 has 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

Secs. 393.70(b)(3), 393.71(b)(2) and 393.71(c)(3). The FHWA would

codify this guidance in Sec. 393.71(b)(3).

The FHWA is proposing to revise 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 connections 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 would codify 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

The FHWA is proposing to amend 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 this tire. According to the Tire and Rim Association's 1996

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. The

FHWA is proposing to use the 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 would be 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) would be a violation of Sec. 393.75(e) if used

on the front wheels of a truck or truck tractor.

The FHWA 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. Since the prohibition is based

on load carrying capacity, the FHWA is proposing to replace the

[[Page 18184]]

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

The FHWA is proposing that Sec. 393.78 be revised to cross-

reference FMVSS No. 104. The NHTSA requirement has been in effect since

December 1968. Since vehicle manufacturers have been required to meet

the requirements since 1968, the FHWA does not believe that motor

carriers who have maintained their commercial motor vehicles should

have any problem complying with the proposed revision. As for motor

vehicles manufactured before December 1968, they would be 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 would have to 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. The requirements for

vehicles manufactured before December 1968 were originally established

by the Interstate Commerce Commision and were applicable to vehicles

manufactured on and after June 30, 1953.

The FHWA is proposing to remove the exemption for the towing

vehicle in a driveaway-towaway operation because there appears to be no

justification for allowing a vehicle to be driven without both

windshield wipers in proper working order. The proposed change should

not result in an increased economic burden on the motor carrier

industry.

Section 393.79--Windshield Defrosting Device

Section 393.79 would be revised to cross-reference FMVSS No. 103.

Vehicles manufactured on or after December 25, 1968, would be required

to meet the requirements in effect on the date of manufacture. Vehicles

manufactured before December 25, 1968, would be 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 would be 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. The

rule requires the speedometer to be operative 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. The FHWA is proposing to include this

accuracy limit in Sec. 393.82 to make the requirement easier to

understand. The FHWA is also proposing to remove 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 proposed changes should not result in an

increased economic burden on the motor carrier industry.

Section 393.87--Flags on Projecting Loads

Section 393.87 would be revised to make the requirements consistent

with the American Association of State Highway and Transportation

Officials's (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. Since the AASHTO guide appears to cover the majority of the

cases to which the current rule would be applicable, and represents a

consensus of State and industry practices, the FHWA proposes to revise

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 would be required to have the extremities of the load

marked with red or orange fluorescent warning flags. Each warning flag

would be required to 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 would be required if the projecting load is

610 mm (2 feet) wide or less. Two warning flags would be required if

the projecting load is wider than 610 mm. Flags would be 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

The FHWA is taking this opportunity to clarify and simplify 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. Since these deadlines have passed, the FHWA is

proposing to delete the references from Sec. 393.94.

In addition, the FHWA is proposing to update 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. The FHWA would

incorporate by reference the 1983 version and remove the footnote to

paragraph (c). Information on the availability of the ANSI document

would be covered under Sec. 393.7.

Section 393.95 Emergency Equipment on All Power Units

The FHWA is proposing to eliminate 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

and limited the applicability of the 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) would also be 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

would still be using fire extinguishers that are more than 20 years

old.

The FHWA would revise Sec. 393.95 by removing the specifications

for bidirectional warning triangles manufactured prior to January 1,

1974. Such triangles are already prohibited on

[[Page 18185]]

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, would be affected.

The FHWA would revise the requirements on the mounting of fire

extinguishers to provide more specific guidance. Fire extinguishers

would be 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, the agency is proposing to

replace 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. The UL has recommended that the FHWA consider referencing

the Environmental Protection Agency's regulations under Subpart G of 40

CFR 82, Protection of Stratospheric Ozone. Subpart G implements section

612 of the Clean Air Act 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 proposed 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. The FHWA is therefore proposing to require that fire

extinguishers comply with the toxicity provisions of the SNAP

regulations. While the other issues (ozone depletion, global warming,

etc.) are important, there would be no practical reason to address

these issues in Sec. 393.95.

Section 93.102--Securement Systems

On July 6, 1994, the FHWA amended Sec. 393.102(b) to adopt the use

of working load limits (WLL) in specifying the minimum strength of

cargo securement devices (59 FR 34712). Under the new rule, the

aggregate working load limit of the tiedown assemblies used to secure

an article against movement in any direction must be at least \1/2\

times the weight of the article secured. Although the rule did not

require manufacturers to attach a WLL label to their products, it did

add a table of working load limits for unmarked webbing, wire rope,

etc., to provide motor carriers with a means of determining the number

of tiedown assemblies required.

The FHWA did not provide guidance on unmarked welded steel chain,

however. The National Association of Chain Manufacturers' (NACM) Welded

Steel Chain Specifications (which were incorporated by reference into

Sec. 393.102(b)) include guidelines on the marking of chain. While

grades 43, 70, and 80 have periodic embossing for identification

purposes, Grade 30, or proof coil chain, is marked at the option of the

manufacturer. The use of unmarked chain for cargo securement purposes

would not be a cause for concern if all unmarked chain were the same

grade or strength. The FHWA has no indication that this is the case.

Generally, manufacturers which meet the NACM's guidelines would

mark their chain accordingly. But some manufacturers which produce

chain that meets the NACM guidelines may choose, for whatever reason,

not to mark their products. If unmarked chains of varying grades are

readily available, motor carriers could unknowingly violate

Sec. 393.102(b) by failing to have an adequate number of securement

devices. The consequences for a load such as a steel or aluminum coil

could be fatal to other motorists.

The risks of such an accident could be greatly minimized by

prohibiting motor carriers from using unmarked chain. Before doing so,

the FHWA would have to quantify the potential economic burden on the

motor carrier industry and those involved with the manufacture, sale,

and distribution of unmarked chain. Since the FHWA has no reliable

information on the number of manufacturers, distributors, and retailers

of unmarked chain, the quality or strength of such chain, or the amount

of this chain currently in use by motor carriers and in retailers''

stock, it would be inappropriate to propose a prohibition at this time.

However, in view of the potential safety hazards of motor carriers

misidentifying unmarked chain, the FHWA is proposing that all unmarked

welded steel chain be considered to have a working load limit equal to

that of grade 30 proof coil. This is consistent with the way in which

the FHWA addressed the use of synthetic cordage (e.g., nylon,

polypropylene, polyester) in the July 6, 1994, final rule. The FHWA

specifically requests comments on this proposal.

Section 393.201--Frames

In the final rule published on December 7, 1988 (53 FR 49380)

prohibiting cracked, loose, sagging or broken frames, the FHWA

inadvertently failed to include trailer frames. The FHWA proposes to

remedy this oversight by replacing ``bus, truck and truck-tractor''

with the term ``commercial motor vehicles'' in paragraph (a).

The FHWA is proposing to revise Sec. 393.201(d) to make the

regulation more practical. Paragraph (d) was meant to prohibit welding

on vehicle frames constructed of certain types of steel which would be

weakened by the welding process. However, the current wording is overly

restrictive. To address this issue, paragraph (d) would be revised to

allow welding which is performed in accordance with the vehicle

manufacturer's recommendations.

In addition, the FHWA is proposing that paragraph (f) be removed.

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

The Truck Trailer Manufacturers Association (TTMA) petitioned the

FHWA to amend part 393 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. The 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 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

[[Page 18186]]

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.

The FHWA believes that the petition has merit and proposes to amend

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.

Section 393.209--Steering Wheel Systems

The FHWA is proposing to amend 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. Since there is no apparent technical basis for having a less

stringent standard for 406 mm (16 inch) diameter steering wheel systems

the FHWA proposes to change the steering wheel lash limit to 108 mm

(4\1/4\ inches).

The FHWA is proposing the addition of 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

that would be adopted for these steering wheel diameters would be

consistent with the 14 degree and 30 degree limits currently used for

manual and power steering systems respectively.

Section 393.209 would also be 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.

Rulemaking Analyses and Notices

All comments received before the close of business on the comment

closing date indicated above will be considered and will be available

for examination in the docket at the above address. Comments received

after the comment closing date will be filed in the docket and will be

considered to the extent practicable, but the FHWA may issue a final

rule at any time after the close of the comment period. In addition to

late comments, the FHWA will also continue to file in the docket

relevant information that becomes available after the comment closing

date, and interested persons should continue to examine the docket for

new material.

Executive Order 12866 (Regulatory Planning and Review) and DOT

Regulatory Policies and Procedures

The FHWA has considered the impacts of this document and has

determined that it is neither a significant rulemaking action within

the meaning of Executive Order 12866 nor a significant rulemaking under

the regulatory policies and procedures of the Department of

Transportation. The rulemaking would amend parts 390, 392, and 393 of

the FMCSRs by removing obsolete and redundant regulatory language;

responding to several petitions for rulemaking; providing improved

definitions of vehicle types, systems, and components; resolving

inconsistencies between part 393 and the FHWA's periodic inspection

criteria (appendix G to subchapter B); resolving inconsistencies

between part 393 and the NHTSA's Federal Motor Vehicle Safety Standards

(49 CFR 571); and codifying certain FHWA regulatory guidance concerning

the requirements of part 393. Generally, the proposed amendments do not

involve the establishment of new or more stringent requirements but a

clarification of existing requirements. It is anticipated that the

economic impact of this rulemaking will be minimal. Therefore, a full

regulatory evaluation is not required.

The new or more stringent requirements include a cross-reference to

the NHTSA's compressed natural gas (CNG) fuel container regulations

which would result in carriers having to ensure that the CNG containers

are properly maintained. In addition, the agency is proposing to

prohibit certain controls used for dumping air individually from either

of the two-axle suspension systems on a semitrailer equipped with air-

suspended ``spread'' or ``split'' tandem axles. The FHWA does not

believe the new requirements will result in an increased economic

burden on the motor carrier industry.

Regulatory Flexibility Act

In compliance with the Regulatory Flexibility Act (5 U.S.C. 601-

612), the FHWA has evaluated the effects of this rule on small

entities. Based on this evaluation, and for the reasons set forth in

the preceeding paragraph, the FHWA certifies that this rule would not

have a significant economic impact on a substantial number of small

entities.

Executive Order 12612 (Federalism Assessment)

This action has been analyzed in accordance with the principles and

criteria contained in Executive Order 12612, and it has been determined

that this rule does not have sufficient federalism implications to

warrant the preparation of a Federalism Assessment.

Executive Order 12372 (Intergovernmental Review)

Catalog of 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 document does not contain information collection requirements

for the purposes of the Paperwork Reduction Act of 1980 [44 U.S.C. 3501

et seq.].

National Environmental Policy Act

The agency has analyzed this rulemaking for the purpose of the

National Environmental Policy Act of 1969 (42 U.S.C. 4321 et seq.) and

has determined that this action would not have any effect on the

quality of the environment.

[[Page 18187]]

Regulation Identification Number

A regulation identification number (RIN) is assigned to each

regulatory action listed in the Unified Agenda of Federal Regulations.

The Regulatory Information Service Center publishes the Unified Agenda

in April and October of each year. The RIN contained in the heading of

this document can be used to cross-reference this action with the

Unified Agenda.

List of Subjects in 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: April 1, 1997.

Jane Garvey,

Acting Administrator, Federal Highway Administration.

In consideration of the foregoing, the FHWA proposes to amend title

49, Code of Federal Regulations, subchapter B, chapter III, as follows:

PART 390--[AMENDED]

1. The authority citation for Part 390 continues to read as

follows:

Authority: 49 U.S.C. 5901-5907, 13301, 13902, 31132, 31133,

31136, 31502, and 31504; 49 CFR 1.48.

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 set of wheels on the surface of

the roadway is being transported

(1) between a vehicle manufacturer and a dealership or purchaser,

(2) between a dealership or other entity selling or leasing the

vehicle and a purchaser or lessee,

(3) to a maintenance/repair facility for the repair of disabling

damage (as defined in Sec. 390.5), or

(4) by means of a saddle-mount.

* * * * *

PART 392--[AMENDED]

3. The authority citation for Part 392 is revised to read as

follows:

Authority: Section 1041(b) of Pub. L. 102-240, 105 Stat. 1914,

1993 (1991), 49 U.S.C. 31136 and 31502; 49 CFR 1.48.

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

are obscured by the tailboard, or by any part of the load, by dirt, or

otherwise.

(b) Exception. The conspicuity treatments on the front end

protection devices of the trailer may be obscured by part of the load

being transported.

PART 393--[AMENDED]

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

follows:

Authority: Section 1041(b) of Pub. L. 102-240, 105 Stat. 1914,

1993 (1991); 49 U.S.C. 31136 and 31502; 49 CFR 1.48.

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 commercial motor vehicle, or cause or permit it to be

operated, unless it is equipped in accordance with the requirements and

specifications of this part.

7. Section 393.5 is amended by removing the definition of ``bus'';

and by adding 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,'' ``intermodal shipping container,''

``multi-piece windshield,'' ``split service brake system,'' ``tow

bar,'' ``trailer kingpin,'' ``vacuum brake system,'' ``windshield'';

and by revising the definitions of ``chassis,'' ``clearance lamp,''

``container chassis'' (now ``container chassis trailer''), ``heater,''

``heavy hauler trailer,'' ``parking brake system,'' ``side marker lamp

(intermediate),'' and ``side marker lamps'', keeping them in

alphabetical order, 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 headlamp 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 mounted on the permanent structure of the

vehicle as near as practicable to the upper left and right extreme

edges that provide light to the front or rear to indicate the overall

width and height of the vehicle.

Container chassis trailer. A semitrailer of skeleton construction

[[Page 18188]]

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 mounted to provide illumination

forward of the vehicle under conditions of rain, snow, dust, or fog.

The lamp may be used with a lower beam headlamp or switch controlled in

conjunction with the headlamps and used at the driver's discretion with

either low or high beam headlamps.

* * * * *

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.

* * * * *

Intermodal shipping container. An article of transport equipment;

(1) Of a permanent character and accordingly strong enough to be

suitable for repeated use;

(2) Specially designed to facilitate the carriage of goods by one

or more modes of transport, without intermediate reloading;

(3) Fitted with devices permitting its ready handling, particularly

its transfer from one mode of transport to another;

(4) So designed as to be easy to fill and empty; and

(5) Having an internal volume of one cubic meter (35.3 cubic feet)

or more.

* * * * *

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 shown to the side of a

motor vehicle 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 permanent structure of the

motor vehicle as near as practicable to the front and rear edges, 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.

8. Section 393.7 is amended by adding paragraphs (b)(7) and (b)(8)

to read as follows:

Sec. 393.7 Matter incorporated by reference.

* * * * *

(b) * * *

(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, 11 West 42nd Street, New York, New York 10036.

* * * * *

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

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

10. Section 393.9 is revised to read as follows:

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

reflectors.

(a) All lamps required by this subpart shall be capable of being

operated at all times. This paragraph shall not be construed to require

that any auxiliary or additional lamp be capable of operating at all

times.

(b) Lamps and reflective devices/material required by this subpart

must not be obscured by the tailboard, or by any part of the load, by

dirt, or otherwise. Exception: The conspicuity treatments on the front

end protection devices may be obscured by part of the load being

transported.

11. Section 393.11 is amended by revising paragraphs (a) through

(c), table 1 and footnotes 4 through 10 and 15, and adding footnotes 16

and 17 to read as follows:

Sec. 393.11 Lamps and reflective devices.

(a)(1) Lamps and reflex reflectors. Table 1 of this section

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 this subpart 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

[[Page 18189]]

requirements of paragraph (b) of this section 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 geometric 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 (49 CFR 571.108, S5.7.1), reflex

reflectors that meet the requirements FMVSS No. 108 (49 CFR 571.108,

S5.7.2), or a combination of retroreflective sheeting and reflex

reflectors that meet the requirements of FMVSS No. 108 (49 CFR 571.108,

S5.7.3). The conspicuity system shall be installed and located as

specified in FMVSS No. 108 (49 CFR 571.108) [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, tail

lamp, or other lamp which is optically combined with an amber stop lamp

or tail lamp.

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 the Not less than A, B, C

same height, with 559 mm (22

an equal number at inches) nor

each side of the more than

vertical centerline 1,372 mm (54

as far apart as inches).

practicable.

Turn signal (front). See 2 Amber............ At or near the One on each side of Not less than A, B, C

footnotes #2 and 12. front. the vertical 381 mm (15

centerline at the inches) nor

same height and as more than

far apart as 2,108 mm (83

practicable. inches).

Identification lamps (front). 3 Amber............ Front.......... As close as All three on B, C

See footnote #1. practicable to the the same level

top of the vehicle, as close as

at the same height, practicable to

and as close as the top of the

practicable to the motor vehicle.

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 2 Red.............. Rear........... One lamp on each Both on the A, B, C, D, E, F, G, H

and 11. side of the same level

vertical centerline between 381 mm

at the same height (15 inches)

and as far apart as and 1,829 mm

practicable. (72 inches).

Stop lamps. See footnotes #5 2 Red.............. Rear........... One lamp on each Both on the A, B, C, D, E, F, G

and 13. side of the same level

vertical centerline between 381 mm

at the same height (15 inches)

and as far apart as and 1,829 mm

practicable. (72 inches).

[[Page 18190]]

Clearance lamps. See 2 Amber............ One on each One on each side of Both on the B, C, D, G, H

footnotes #8, 9, 10, 15 & 17. side of the the vertical same level as

rear of the centerline to high as

vehicle. indicate overall practicable.

width.

2 Red.............. One on each One on each side of Both on the B, D, G, H

side of the the vertical same level as

front of the centerline to high as

vehicle. indicate overall practicable.

width.

Reflex reflector, 2 Amber............ One on each At or near the Between 381 mm A, B, D, F, G

intermediate (side). side. midpoint between (15 inches)

the front and rear and 1,524 mm

side marker lamps, (60 inches).

if the length of

the vehicle is more

than 9,144 mm (30

feet).

Reflex reflector (rear). See 2 Red.............. Rear........... One on each side of Both on the A, B, C, D, E, F, G

footnotes #5, 6, and 8. the vertical same level,

centerline, as far between 381 mm

apart as (15 inches)

practicable and at and 1,524 mm

the same height. (60 inches).

Reflex reflector (rear side). 2 Red.............. One on each As far to the rear Both on the A, B, D, F, G

side (rear). as practicable. same level,

between 381 mm

(15 inches)

and 1,524 mm

(60 inches).

Reflex reflector (front 2 Amber............ One on each As far to the front Between 381 mm A, B, C, D, F, G

side). See footnote #16. side (front). as practicable. (15 inches)

and 1,524 mm

(60 inches).

License plate lamp (rear). 1 White............ At rear license No requirements A, B, C, D, F, G

See 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 front Not less than A, B, C, D, F

footnote #16. side. as practicable. 381 mm (15

inches).

Side marker lamp, 2 Amber............ One on each At or near the Not less than A, B, D, F, G

intermediate. side. midpoint between 381 mm (15

the front and rear inches).

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 rear Not less than A, B, D, F, G

footnotes #4 and 8. side. as practicable. 381 mm (15

inches) and,

on the rear of

trailers, not

more than

1,524 mm (60

inches).

[[Page 18191]]

Turn signal (rear). See 2 Amber or red..... Rear........... One lamp on each Both on the A, B, C, D, E, F, G

footnotes #5 and 12. side of the same level,

vertical centerline between 381 mm

as far apart as (15 inches)

practicable. and 2,108 mm

(83 inches).

Identification lamp (rear). 3 Red.............. Rear........... One as close as All three on B, D, G

See footnotes #3, 7, and 15. practicable to the the same level

vertical as close as

centerline. One on practicable to

each side with lamp the top of the

centers spaced not vehicle.

less than 152 mm (6

inches) or more

than 305 mm (12

inches) apart.

Vehicular hazard warning 2 Amber............ Front.......... One lamp on each Both on the A, B, C,

signal flasher lamps. See side of the same level,

footnotes #5 and 12. vertical between 381 mm

centerline, as far (15 inches)

apart as and 2,108 mm

practicable. (83 inches).

2 Amber or red..... Rear........... One lamp on each Both on the A, B, C, D, E, F, G

side of the same level,

vertical between 381 mm

centerline, as far (15 inches)

apart as and 2,108 mm

practicable. (83 inches).

Backup lamp. See footnote #14 1 White............ Rear........... Rear................ No requirement. A, B, C

Parking lamp................. 2 Amber or white... Front.......... One lamp on each Both on the A

side of the same level,

vertical between 381 mm

centerline, as far (15 inches)

apart as and 1,829 mm

practicable. (72 inches).

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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.

Note: Lamps and reflectors may be combined as permitted by Sec. 393.22 and S5.4 of 49 CFR 571.108, Equipment combinations.

* * * * *

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) nor 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.

[[Page 18192]]

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

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