[Federal Register Volume 63, Number 93 (Thursday, May 14, 1998)]
[Proposed Rules]
[Pages 26759-26764]
From the Federal Register Online via the Government Publishing Office [www.gpo.gov]
[FR Doc No: 98-12753]


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DEPARTMENT OF TRANSPORTATION

Federal Highway Administration

49 CFR Part 393

[FHWA Docket No. FHWA-97-3201]
RIN 2125-AE15


Parts and Accessories Necessary for Safe Operation; Rear Impact 
Guards and Rear Impact Protection

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 the Federal Motor Carrier 
Safety Regulations (FMCSRs) to require that certain trailers and 
semitrailers with a gross vehicle weight rating (GVWR) of 4,536 
kilograms (kg) (10,000 pounds) or more, and manufactured on or after 
January 26, 1998, be equipped with rear impact guards that meet the 
requirements of Federal Motor Vehicle Safety Standard (FMVSS) No. 223. 
The rear impact guards would be installed to ensure that the trailer or 
semitrailer meets the rear impact protection requirements of FMVSS No. 
224. This rulemaking is intended to ensure that the rear impact 
protection requirements of the FMCSRs are consistent with the FMVSSs 
and to improve the safety of operation of commercial motor vehicles 
(CMVs) by reducing the incidence of passenger compartment intrusion 
during underride accidents in which the passenger vehicle strikes the 
rear of the trailer. With regard to trailers manufactured before 
January 26, 1998, the FHWA is not proposing that motor carriers be 
required to retrofit a rear impact guard that conforms to FMVSS No. 
223. However, motor carriers operating these trailers would be required 
to continue complying with the FHWA's current requirements for rear 
impact guards and rear impact protection.

DATES: Comments must be received on or before July 13, 1998.

ADDRESSES: Submit written, signed comments to the docket number that 
appears in the heading of this document 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 from 10 a.m. to 5 p.m., et., 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, (202) 366-4009, or Mr. Charles Medalen, 
Office of the Chief Counsel, (202) 366-1354, Federal Highway 
Administration, Department of Transportation, 400 Seventh Street, SW., 
Washington, D.C. 20590. Office hours are from 7:45 a.m. to 4:15 p.m., 
e.t., Monday through Friday, except Federal holidays.

SUPPLEMENTARY INFORMATION:

Electronic Access

    Internet users can access all comments received by the U.S. DOT 
Dockets, Room PL-401, by using the universal resource locator (URL): 
http://dms.dot.gov. It is available 24 hours each day, 365 days each 
year. Please follow the instructions online for more information and 
help.
    An electronic copy of this document may be downloaded using a modem 
and suitable communications software from the Federal Register 
Electronic Bulletin Board Service at (202) 512-1661. Internet users may 
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fedreg">http://www.nara.gov/nara/
fedreg</a> and the Government Printing Office's database at: <a href="http://
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www.access.gpo.gov/su__docs</a>.

Background

    On January 24, 1996 (61 FR 2003), the National Highway Traffic 
Safety Administration (NHTSA) published a final rule creating Federal 
Motor Vehicle Safety Standards (FMVSSs) Nos. 223, Rear Impact Guards, 
and 224, Rear Impact Protection. The requirements apply to trailers 
manufactured on or after January 26, 1997.
    The first standard, FMVSS No. 223 (49 CFR 571.223), specifies 
performance requirements that rear impact guards must meet before they 
can be installed on new trailers and semitrailers. It specifies 
strength requirements for the impact guards as well as test procedures 
that manufacturers and the NHTSA will use to determine compliance with 
the standard. The standard also requires the guard manufacturer to 
permanently label the impact guard to certify that the device meets the 
requirements and to provide instructions on the proper installation of 
the guard.
    The second standard, FMVSS No. 224 (49 CFR 571.224), requires that 
most new trailers and semitrailers with a gross vehicle weight rating 
(GVWR) of 4,536 kg (10,000 pounds) or more be equipped with a rear 
impact guard meeting FMVSS No. 223. Requirements for the location of 
the guard relative to the rear end and sides of the trailer are also 
specified in the vehicle standard. In addition, the vehicle standard 
requires that the guard be mounted on the trailer or semitrailer in 
accordance with the instructions of the guard manufacturer.

History of Current FHWA Requirements

    The first Federal requirements concerning heavy vehicle rear 
underride protection were issued in 1952 by the Bureau of Motor 
Carriers of the Interstate Commerce Commission (ICC) (presently the 
Office of Motor Carriers of the Federal Highway Administration). The 
regulation, which is still in effect (49 CFR 393.86), requires heavy 
trucks, trailers, and semitrailers to be equipped with a rear-end 
protection device

[[Page 26760]]

designed to help prevent underride. The rule requires that the ground 
clearance of the underride guard be no more than 760 mm (30 inches) 
when the vehicle is empty. The rule also requires that the underride 
guard be located no more than 610 mm (24 inches) forward of the rear of 
the vehicle and that it extend laterally to within 460 mm (18 inches) 
of each side. The underride device is required to be ``substantially 
constructed and firmly attached.''
    The language that the ICC adopted was based upon the 
recommendations of the Bumper Heights Committee of the Society of 
Automotive Engineers (SAE). On January 2, 1947, the Director of the 
Bureau of Motor Carriers sent a letter to the SAE requesting that the 
Bumper Heights Committee consider expanding its work on passenger car 
bumpers to include recommendations for rear bumpers on heavy vehicles. 
The SAE provided a report entitled ``Recommendations Covering Rear 
Bumpers on Trucks and Trailers,'' in September 1947. A copy of the 
report is included in the docket file.

NHTSA and FHWA Efforts To Develop Improved Underride Regulations

    Efforts to improve the Federal requirements for rear underride 
protection started in the late 1960's. On October 14, 1967, the FHWA's 
National Highway Safety Bureau (NHSB, the predecessor of the NHTSA) 
issued an advance notice of proposed rulemaking (ANPRM) requesting 
comments on possible amendments to the Federal Motor Vehicle Safety 
Standards (32 FR 14278).
    On March 19, 1969, the NHSB issued a notice of proposed rulemaking 
on rear underride protection devices (34 FR 5383). The proposal would 
have applied to all new trucks and trailers (except pole trailers) with 
a GVWR greater than 4,536 kgs (10,000 pounds). The maximum ground 
clearance for the underride protection would have been 457 mm (18 
inches). The proposal also included a static strength test that would 
have required that the device deflect no more than 381 mm (15 inches) 
forward of the rearmost part of the vehicle when a force of 333,600 
Newtons (75,000 pounds) was applied.
    In 1970, the NHSB (acting as a regulatory agency within the 
Department of Transportation but independent of the FHWA) issued a 
supplemental notice of proposed rulemaking (SNPRM) in response to 
comments to the 1969 NPRM (35 FR 12956, August 14, 1970). The 
commenters had expressed concern about operational problems that would 
be created if the ground clearance for the rear underride guard could 
not exceed 457 mm (18 inches). Commenters also expressed concerns about 
the test procedures. Although the NHSB did not increase the ground 
clearance for the underride guard, the agency proposed reducing the 
test force requirements from 333,600 Newtons (75,000 pounds) to 222,400 
Newtons (50,000 pounds).
    The NHTSA (successor to the NHSB pursuant to the Highway Safety Act 
of 1970) terminated the rulemaking on rear underride on June 18, 1971 
(36 FR 11750). The NHTSA stated that ``[b]ased upon the information 
received in response to the notices and evaluations of cost and 
accident data, the Administration has concluded that, at the present 
time, the safety benefits achievable in terms of lives and injuries 
saved would not be commensurate with the cost of implementing the 
proposed requirements.''
    In response to a petition for rulemaking from the Insurance 
Institute for Highway Safety (IIHS) and a March 16, 1977, hearing 
before the Senate Committee on Commerce, Science, and Transportation on 
auto-truck crash safety, the NHTSA and the FHWA jointly issued an ANPRM 
requesting information on possible revisions to 49 CFR 571 and 49 CFR 
393.86 (42 FR 43414, August 29, 1977). The notice stated:

    [I]t is the conclusion of the Department of Transportation that 
the present requirements should be reexamined because the problem of 
rear underride accidents remains, and it is likely to become more 
severe as automobiles become smaller and are used in greater 
numbers. Improved rear end protection devices on heavy motor 
vehicles that may contribute substantially to saving lives and 
preventing injuries may be possible without incurring either 
unacceptable costs or unacceptable restrictions on operations.

    The notice also indicated that the FHWA was starting a research 
program to ``establish the level of rear underride protection needed to 
reduce injuries and fatalities in a variety of realistic accident 
situations.'' The goals of the research program were described:

    This will be an attempt to develop a number of rear underride 
designs to determine the desired level of performance, giving due 
consideration to cost, weight, and operational problems. Results of 
this contract effort will be used in determining what form any 
amendments to FMCSR Section 393.86 and FMVSS Part 571 should take.

    The FHWA and the NHTSA worked together in developing a rear 
underride research program and initiated two separate studies. The FHWA 
contracted with the Texas Transportation Institute (TTI) of Texas A&M 
University to develop low-cost underride guards that would be practical 
and effective in preventing underride. The NHTSA contracted with 
Dynamic Sciences, Inc. (DSI) to develop compliance test procedures for 
the guards. These joint contract efforts were intended to generate 
sufficient data to support a rule applicable to vehicles with a GVWR 
greater than 4,536 kg (10,000 pounds).
    The research contracts focused on preventing excessive underride 
primarily through the use of a rigid guard having a low ground 
clearance. This approach was similar to that followed by IIHS in a test 
program conducted in 1976. The tests performed by TTI and DSI 
demonstrated what the IIHS program had shown earlier: Excessive 
underride could be prevented with rigid guards. However, the tests also 
indicated that rigid guards increase the deceleration forces 
experienced by passenger car occupants during a crash and therefore 
increase the risk of injury due to hazards other than underride.
    Restrained anthropomorphic test devices (commonly referred to as 
test dummies) placed in passenger cars that were crashed into the rigid 
guards at speeds of 56.3 km/hr (35 mph) or more experienced injury 
responses (forces detected by sensors in the test dummies) that were 
outside of the ranges allowed under FMVSS No. 208, Occupant Crash 
Protection. This was significant because the accident statistics 
available at that time indicated that most accidents in which a 
passenger car collided with a heavy vehicle rear end were survivable. 
The data further indicated that a majority of the fatalities that 
occurred took place in accidents that did not involve excessive 
underride.
    Dynamic Sciences, Inc. also tested production underride devices 
that were typical of the guards in use at the time. The guards were not 
able to prevent small cars from excessively underriding test trailers 
at collision speeds above 48.3 km/hr (30 mph). In these tests, the 
dummies experienced injury responses that were above the limits of 
FMVSS No. 208. When small cars were crashed into the guards, the guards 
did not fail (i.e., did not permanently deform). In tests of large cars 
at collision speeds of 48.3 km/hr (30 mph), underride was excessive in 
offset collisions but not when the collision was centric. Occupant 
injury responses were within the allowable limits of FMVSS No. 208 and 
none of the guards failed. Occupant injury responses were also within 
the permissible limits of FMVSS No. 208 when the large cars were 
crashed into the guard at 64.4 km/hr (40 mph). However, the underride 
was excessive

[[Page 26761]]

and the guards were permanently deformed.
    In addition, the TTI program tested a hydraulic energy-absorbing 
guard manufactured by Quinton-Hazell Automotive Ltd. (Quinton-Hazell). 
The Quinton-Hazell device was very effective at preventing excessive 
underride, reducing occupant injury responses, and reducing damage to 
the colliding vehicle.
    The TTI also conducted two tests in which passenger vehicles were 
crashed into a van-type trailer that had no guard but whose adjustable 
rear wheels were set in the rearmost position. The purpose of these 
tests was to determine the effectiveness of rear tandems as a means for 
preventing underride. The tests demonstrated that the rear wheels, when 
placed at the extreme rear of the truck or trailer, prevent excessive 
underride at approximately 56.3 km/hr (35 mph). Further, the restrained 
dummies used in these tests experienced injury responses that were 
within the allowable limits of FMVSS No. 208.
    The NHTSA issued an NPRM on January 8, 1981 (46 FR 2136). The 
proposed standard would have required large trucks and trailers to be 
equipped with an underride guard that met specified strength 
requirements and prescribed requirements concerning the configuration 
of the impact guard. The proposed standard differed from the FHWA's 
regulation in three ways. First, the NHTSA's proposal included 
objective strength requirements for the guard. Second, the proposed 
configuration requirements would have resulted in the guard having a 
lower ground clearance and being closer to the rear of the vehicle. 
Third, the NHTSA's proposed impact guard would have been wider (i.e., 
closer to the sides of the vehicle).
    Based upon comments received in response to the 1981 NPRM and the 
results of the TTI and DSI studies, the NHTSA published a supplemental 
notice of proposed rulemaking (SNPRM) (57 FR 252, January 3, 1992). 
Instead of a vehicle-based safety standard as proposed in 1981, the 
NHTSA proposed separate standards for the impact guard as an item of 
motor vehicle equipment and for the vehicle. The equipment standard 
would specify the strength requirements that the guard would have to 
meet when attached to a rigid test fixture rather than the vehicle. The 
vehicle standard would require vehicle manufacturers to install a guard 
meeting the equipment standard, and to certify that the trailer has an 
impact guard installed at the required location.
    The NHTSA's Vehicle Research and Test Center (VRTC) initiated a 
program to develop and evaluate the effectiveness of a rear impact 
guard design that would meet the proposed requirements. The VRTC 
developed a static test fixture and fabricated an impact guard design 
that met, but did not exceed, the minimum requirements. A number of 
additional guards were fabricated and tested to evaluate the 
repeatability of the design.
    In addition, a rigid simulated trailer was developed to mount the 
guard for dynamic testing. Two sub-compact and two compact vehicle 
models were selected for crash testing to evaluate the effectiveness of 
the guard design in preventing rear underride injuries. Tests were 
conducted using the simulated trailer and an actual tractor trailer. A 
crash test was also performed with a rigid guard configuration for 
comparison with the results of the design. The researchers concluded 
that:

    1. The currently proposed maximum guard height of 22 inches 
appeared to adequately engage the structures of all 4 vehicles 
tested [Honda Civic, Ford Tempo, General Motors Saturn, and 
Chevrolet Corsica]. The test vehicles were all high sales volume 
sub-compact and compact models with a low frontal profile.
    a. The guards contacted each vehicle just above the bumper, 
engaging hood and fenders, engine, and upper suspension support 
structures.
    b. The air bag restraints of all 4 vehicles deployed early 
enough to provide protection for the unbelted driver dummy.
    2. For the test conducted, the 22 inch guard height prevented 
occupant compartment intrusion as long as the attachment at the 
guard/trailer interface was sufficiently strong. In one test (the 
first Saturn test), the guard attachment hardware failed. In the 
first test with the production trailer, the trailer sub-frame rails 
to which the guard was attached also failed. In each case, the 
mounting hardware was changed and all subsequent tests produced no 
interface failure or occupant compartment intrusion by the rear end 
of the trailer.
    3. There is a trade-off between energy absorption, which reduces 
occupant accelerations by allowing the guard to give, and limiting 
underride, which reduces the possibility of passenger compartment 
intrusion. It is possible to significantly increase the strength of 
the guard, without exceeding the NHTSA's Occupant Crash Protection 
criteria [FMVSS No. 208 (49 CFR 571.208) Occupant Crash Protection].

    The Corsica test with the ``minimally compliant'' guard design 
resulted in a clearance of 0.2 inches between the rear of the trailer 
and the forward-most part of the windshield after the collision, and 
low test dummy injury responses. A rigid guard test for the same 
vehicle resulted in 32.2 inches of clearance to the windshield. Dummy 
injury responses increased with one chest response just over 60 g's [60 
times gravitational acceleration, 9.825 m/sec<SUP>2</SUP> (32.2 feet/
sec<SUP>2</SUP>)], but in general response levels were similar to that 
seen in [FMVSS No. 208 compliance] tests.
    A copy of the NHTSA's report, ``Heavy Truck Rear Underride 
Protection,'' DOT HS 808-081, June 1993, has been placed in the docket 
file.
    On January 24, 1996, the NHTSA issued a final rule establishing new 
safety standards for rear impact guards and rear impact protection (61 
FR 2004). The rule applies to certain trailers manufactured on or after 
January 26, 1998. One of the major differences between the final rule 
and the SNPRM is the addition of a requirement for energy absorption. 
The SNPRM would have permitted fairly rigid guards because it did not 
require the guard to yield in response to force. The preamble to the 
final rule indicated that rigid guards may stop the passenger vehicles 
too quickly, causing occupant deaths and injuries.
    The NHTSA also changed some of the impact guard configuration 
requirements to allow rounded guard ends. To account for high rear 
overhang on trailers such as automobile transporters, the NHTSA changed 
the definition of the vertical zone to be considered when determining 
the trailer's rear extremity. The location of the guard is based upon 
the location of the rear extremity.
    On January 26, 1998, the NHTSA issued a final rule responding to 
petitions for reconsideration of the 1996 final rule, and making 
technical amendments to the rear impact guard requirements (63 FR 
3654). The 1998 final rule clarified the applicability of the energy-
absorption requirements with regard to cargo tank motor vehicles, as 
defined in 49 CFR 171.8, excluded pulpwood trailers from the rear 
impact protection requirements (a definition of pulpwood trailer was 
added to Sec. 571.224), and revised the definition of special purpose 
vehicle.

Discussion of the FHWA Proposal

    To ensure that the safety benefits intended by the NHTSA rulemaking 
are achieved, the FHWA is proposing to amend Sec. 393.86 to establish a 
requirement that certain trailers manufactured on or after January 26, 
1998, and operated in interstate commerce, be equipped to comply with 
FMVSS Nos. 223 and 224. This action is necessary because the FMVSSs are 
applicable only to vehicle and vehicle component manufacturers. In the 
absence of an amendment to the FMCSRs, there would be no Federal

[[Page 26762]]

requirement that motor carriers maintain their trailers to conform to 
the rear impact protection requirements of FMVSS No. 224, or repair 
damaged rear impact guards. Motor carriers could also replace rear 
impact guards with devices that failed to comply with the NHTSA 
requirements.
    Paragraph (a) of Sec. 393.86 would provide a general statement of 
the applicability of the new rear impact guard requirements and cross 
reference FMVSS Nos. 223 and 224. Paragraph (a) would also identify the 
types of trailers (which would be defined in Sec. 393.5) that are 
exempted from the new rear impact guard requirements. Paragraphs (b) 
through (e) would specify the following requirements, respectively: The 
minimum width for the impact guard; the maximum ground clearance; the 
maximum distance from the rear of the vehicle to the rear surface of 
the impact guard; and the cross-sectional vertical height of the 
horizontal member of the guard. Paragraph (f) would specify the 
certification and labeling requirements. The agency is proposing to 
include detailed requirements in Sec. 393.86(b) through (f) to help 
motor carriers quickly determine if the underride device on a newly 
manufactured trailer meets the NHTSA's requirements, and to assist 
State agencies responsible for enforcing motor carrier safety 
regulations.
    The existing requirements (for all commercial motor vehicles 
manufactured after December 31, 1952, except trailers or semitrailers 
manufactured on or after January 26, 1998) would be covered under 
paragraphs (g) through (i). Paragraph (g) would specify the minimum 
dimensions for the rear impact guard as installed on the motor vehicle. 
Paragraph (h) would specify that the impact guard must be substantially 
constructed and attached by bolts, welding, or other comparable means. 
Paragraph (h) differs from the current attachment requirements in that 
the phrase ``firmly attached'' would be replaced with ``attached by 
means of bolts, welding, or other comparable means'' to make the 
regulations easier to understand and enforce.
    The current language contained in paragraph (e) would be revised 
and included in a new paragraph (i). The FHWA would specify that low 
chassis vehicles, special purpose vehicles, and wheels-back vehicles 
which are constructed and maintained so that the body, chassis, or 
other parts of the vehicle provide rear end protection comparable to an 
impact guard(s) conforming to the requirements of paragraph (g) of 
Sec. 393.86 shall be considered in compliance with the requirements.

Retrofitting

    The FHWA is not proposing a retrofitting requirement for improved 
rear impact protection on trailers and semitrailers manufactured before 
January 26, 1998. There is insufficient accident, cost, and research 
data to support such a proposal at this time. The types of data 
required to justify a retrofitting requirement would be much more 
detailed than the information analyzed by the NHTSA.
    Section 393.86(g) does not specify minimum strength requirements, 
or energy absorption capabilities, nor does it prohibit the use of 
impact guards that have a ground clearance less than 762 mm (30 
inches), and impact guards that are closer than 61 cm (24 inches) to 
the rear and 45.7 cm (18 inches) to the sides of the vehicle. In 
addition, the existing standard allows impact guards to be constructed 
of more than one section provided the distance between the sections 
does not exceed 610 mm (24 inches). As a result, manufacturers have 
used a number of rear impact guard designs to satisfy the FHWA's 
requirements.
    To develop a sound technical basis for a retrofitting proposal, the 
FHWA would have to establish criteria for determining which of the 
older impact guard designs should be considered acceptable, and which 
ones should be replaced. The FHWA would then have to estimate the total 
number of guards that would have to be replaced or modified, the total 
cost for replacing or modifying those guards (including lost revenues 
while the trailer was being retrofitted), and the benefits in lives 
saved and injuries prevented if a certain number of vehicles were 
retrofitted. This is particularly difficult because some rear impact 
guards currently in use may meet or exceed the NHTSA's strength 
requirements but fail to meet dimensional or energy absorption 
requirements. Others may meet the dimensional requirements but fall 
short of the minimum strength requirements.
    The FHWA does not have test data or engineering analyses concerning 
the performance capabilities of any of the rear impact guard designs 
currently in use. The ICC did not have authority to regulate vehicle 
and component manufacturers when it issued the first rear underride 
protection requirements in 1952 and, consequently, had no authority to 
compel manufacturers to provide technical data on their products. Also, 
the initial FMVSSs issued by the FHWA did not include rear impact 
protection requirements. Therefore, the agency did not have access to 
this information during the relatively short period of time (between 
1966 and 1970, when the NHTSA was established) in which vehicle and 
component manufacturers were regulated by the FHWA. Because of the lack 
of technical data concerning the performance capabilities of underride 
devices currently in use, the agency cannot prepare an accurate 
estimate of the costs and benefits associated with a retrofitting 
requirement.
    The FHWA specifically requests comments from any interested party 
with data relevant to the costs and benefits of retrofitting.

Applicability to Canadian and Mexican Vehicles

    The FHWA is not proposing an exemption for CMVs operated in the 
United States by Canada- and Mexico-based motor carriers. Although the 
Federal governments of Canada and Mexico have not indicated whether 
they intend to require rear impact guards (which meet the NHTSA 
standard) on newly manufactured trailers operating in their countries, 
the FHWA believes that it is appropriate to require such guards on 
foreign-based trailers manufactured on or after the effective date of 
the NHTSA requirements if those vehicles are operated within the United 
States.
    Vehicles operated in the United States by Canada- and Mexico-based 
motor carriers are required to comply with the existing rear underride 
device requirements. The proposed revision of Sec. 393.86 would require 
that trailers and semitrailers manufactured on or after January 26, 
1998, and operated by foreign-based motor carriers meet the NHTSA 
standards. The FHWA specifically requests comments from Canada- and 
Mexico-based motor carriers and original equipment manufacturers that 
sell trailers and semitrailers for the Canadian and Mexican markets.

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 public docket and 
will be considered to the extent practicable, but the FHWA may adopt 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 
public docket, relevant information that becomes available after the

[[Page 26763]]

comment closing date. Interested persons should continue to examine the 
public docket for new material.

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

    The FHWA has determined that this action is not a significant 
regulatory action within the meaning of Executive Order 12866. This 
rule would, if adopted, require that certain trailers and semitrailers 
manufactured on or after January 26, 1998, be equipped with rear impact 
protection devices meeting the requirements of FMVSS No. 223 and 
installed on trailers in accordance with FMVSS 224. Motor carriers 
would be responsible for maintaining the underride protection devices 
on these trailers. It is anticipated that the economic impact of this 
proposed requirement would be minimal because the NHTSA requires 
trailer manufacturers to equip new trailers and semitrailers with rear 
impact guards and the FHWA's rulemaking would only require motor 
carriers to maintain the improved underride protection devices. It is 
expected that the costs of repairing damaged underride devices would be 
the only economic burden placed upon motor carriers and that this 
burden generally would not exceed the costs of properly repairing 
underride devices on trailers manufactured prior to the effective date 
of the NHTSA's requirements. Accordingly, a full regulatory evaluation 
is not required. For the purposes of the Department of Transportation's 
regulatory policies and procedures, however, the proposed rule would be 
significant because of the substantial public interest in the 
prevention of rear-underride accidents involving commercial motor 
vehicles.

Regulatory Flexibility Act

    In compliance with the Regulatory Flexibility Act (5 U.S.C. 601-
612), the FHWA has evaluated the effects of this proposed rule on small 
entities. This rule would modify the rear impact protection standards 
for trailers in the Federal Motor Carrier Safety Regulations (FMCSRs) 
to make them consistent with the manufacturing standards in the FMVSS 
No. 224, which requires the installation of rear impact protection 
devices conforming to FMVSS No. 223 on certain newly-manufactured 
semitrailers and trailers. The FHWA believes that maintenance costs of 
the rear impact protection devices required under the new FMVSSs will 
be minimal. Therefore, the FHWA hereby certifies that this action 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.

Unfunded Mandates Reform Act

    This proposal would not impose an unfunded Federal mandate, as 
defined by the Unfunded Mandates Reform Act of 1995 (2 U.S.C. 1532 et 
seq.), that will result in the expenditure by State, local, and tribal 
governments, in the aggregate, or by the private sector, or $100 
million or more in any one year.

Paperwork Reduction Act

    This document does not contain information collection requirements 
for the purposes of the Paperwork Reduction Act of 1995 (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.

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 393

    Highways and roads, Motor carriers, Motor vehicle equipment, Motor 
vehicle safety.

    Issued on: April 28, 1998.
Kenneth R. Wykle,
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 393--[AMENDED]

    1. 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.

    2. Section 393.5 is amended by adding the definitions of ``low 
chassis vehicle,'' ``special purpose vehicle,'' and ``wheels back 
vehicle,'' and by revising the definitions of ``pulpwood trailer,'' 
``rear extremity,'' and ``side extremities'' (now ``side extremity'') 
to read as follows:


Sec. 393.5  Definitions.

* * * * *
    Low chassis vehicle. A trailer or semitrailer having a chassis 
which extends behind the rearmost point of the rearmost tires and a 
lower rear surface that meets the guard width, height, and rear surface 
requirements of Sec. 571.224. For vehicles not subject to the 
requirements of Sec. 571.224 on the date of manufacture, the 
configuration requirements of Sec. 393.86(g) may be used.
* * * * *
    Pulpwood trailer. A trailer or semitrailer that is designed 
exclusively for harvesting logs or pulpwood and constructed with a 
skeletal frame with no means for attachment of a solid bed, body, or 
container.
    Rear extremity. The rearmost point on a vehicle that falls above a 
horizontal plane located 560 mm (22 inches) above the ground and below 
a horizontal plane located 1,900 mm (75 inches) above the ground when 
the vehicle is stopped on level ground; unloaded; its fuel tanks are 
full; the tires (and air suspension, if so equipped) are inflated in 
accordance with the manufacturer's recommendations; and the vehicle's 
cargo doors, tailgate, or other permanent structures are positioned as 
they normally are when the vehicle is in motion. Nonstructural 
protrusions such as taillamps, rubber bumpers, hinges and latches are 
excluded from the determination of the rearmost point.
* * * * *
    Side extremity. The outermost point on a side of the vehicle that 
is above a horizontal plane located 560 mm (22 inches) above the 
ground, below a

[[Page 26764]]

horizontal plane located 1,900 mm (75 inches) above the ground, and 
between a transverse vertical plane tangent to the rear extremity of 
the vehicle and a transverse vertical plane located 305 mm (12 inches) 
forward of that plane when the vehicle is unloaded; its fuel tanks are 
full; and the tires (and air suspension, if so equipped) are inflated 
in accordance with the manufacturer's recommendations. Non-structural 
protrusions such as taillights, hinges and latches are excluded from 
the determination of the outermost point.
* * * * *
    Special purpose vehicle. A trailer or semitrailer having work-
performing equipment that, while the vehicle is in transit, resides in 
or moves through the area that could be occupied by the horizontal 
member of the rear impact guard, as defined by the guard width, height 
and rear surface requirements of Sec. 571.224 (paragraphs S5.1.1 
through S5.1.3).
* * * * *
    Wheels back vehicle. A trailer or semitrailer whose rearmost axle 
is permanently fixed and is located such that the rearmost surface of 
the tires (of the size recommended by the vehicle manufacturer for the 
rear axle) is not more than 305 mm (12 inches) forward of the 
transverse vertical plane tangent to the rear extremity of the vehicle.
    3. Section 393.86 is revised to read as follows:


Sec. 393.86  Rear impact guards and rear end protection.

    (a) General requirements for trailers and semitrailers manufactured 
on or after January 26, 1998. Each trailer and semitrailer with a gross 
vehicle weight rating of 4,536 kg (10,000 pounds) or more, and 
manufactured on or after January 26, 1998, must be equipped with a rear 
impact guard that meets the requirements of Federal Motor Vehicle 
Safety Standard No. 223 (49 CFR 571.223) in effect at the time the 
vehicle was manufactured. When the rear impact guard is installed on 
the trailer or semitrailer, the vehicle must, at a minimum, meet the 
requirements of FMVSS No. 224 (49 CFR 571.224) in effect at the time 
the vehicle was manufactured. Trailers and semitrailers subject to this 
paragraph must meet the requirements of paragraphs (b) through (f) of 
this section. The requirements of paragraphs (a) through (f) do not 
apply to pole trailers (as defined in Sec. 390.5); pulpwood trailers, 
low chassis trailers, special purpose trailers, wheels back trailers 
(as defined in Sec. 393.5); and trailers towed in driveaway-towaway 
operations (as defined in Sec. 390.5).
    (b) Impact guard width. The outermost surfaces of the horizontal 
member of the guard must extend to within 100 mm (4 inches) of the side 
extremities of the vehicle. The outermost surface of the horizontal 
member shall not extend beyond the side extremity of the vehicle.
    (c) Guard height. The vertical distance between the bottom edge of 
the horizontal member of the guard and the ground shall not exceed 560 
mm (22 inches) at any point across the full width of the member. Guards 
with rounded corners may curve upward within 255 mm (10 inches) of the 
longitudinal vertical planes that are tangent to the side extremities 
of the vehicle.
    (d) Guard rear surface. At any height 560 mm (22 inches) or more 
above the ground, the rearmost surface of the horizontal member of the 
guard must be within 305 mm (12 inches) of the rear extremity of the 
vehicle. This paragraph shall not be construed to prohibit the rear 
surface of the guard from extending beyond the rear extremity of the 
vehicle. Guards with rounded corners may curve forward within 255 mm 
(10 inches) of the side extremity.
    (e) Cross-sectional vertical height. The horizontal member of each 
guard must have a cross sectional vertical height of at least 100 mm 
(3.94 inches) at any point across the guard width.
    (f) Certification and labeling requirements for rear impact 
protection guards. Each rear impact guard used to satisfy the 
requirements of paragraph (a) of this section must be permanently 
marked or labeled as required by FMVSS No. 223 (49 CFR 571.223, S5.3). 
The label must be on the forward-facing surface of the horizontal 
member of the guard, 305 mm (12 inches) inboard of the right end of the 
guard. The certification label must contain the following information:
    (1) The impact guard manufacturer's name and address;
    (2) The statement ``Manufactured in ________'' (inserting the month 
and year that the guard was manufactured); and,
    (3) The letters ``DOT'', constituting a certification by the guard 
manufacturer that the guard conforms to all requirements of FMVSS No. 
223.
    (g) Requirements for motor vehicles manufactured after December 31, 
1952 (except trailers or semitrailers manufactured on or after January 
26, 1998). Each motor vehicle manufactured after December 31, 1952, 
(except of truck tractors, pole trailers, or vehicles in driveaway-
towaway operations) in which the vertical distance between the rear 
bottom edge of the body (or the chassis assembly if the chassis is the 
rearmost part of the vehicle) and the ground is greater than 76.2 cm 
(30 inches) when the motor vehicle is empty, shall be equipped with a 
rear impact guard(s). The rear impact guard(s) must be installed and 
maintained in such a manner that:
    (1) The vertical distance between the bottom of the guard(s) and 
the ground does not exceed 76.2 cm (30 inches) when the motor vehicle 
is empty;
    (2) The maximum distance between the closest points between guards, 
if more than one is used, does not exceed 61 cm (24 inches);
    (3) The outermost surfaces of the horizontal member of the guard 
are no more than 45.7 cm (18 inches) from each side extremity of the 
motor vehicle;
    (4) The impact guard(s) are no more than 61 cm (24 inches) forward 
of the rear extremity of the motor vehicle.
    (h) Construction and attachment. The rear impact guard(s) must be 
substantially constructed and attached by means of bolts, welding, or 
other comparable means.
    (i) Vehicle components and structures that may be used to satisfy 
the requirements of paragraph (g) of this section. Low chassis 
vehicles, special purpose vehicles, or wheels back vehicles constructed 
and maintained so that the body, chassis, or other parts of the vehicle 
provide the rear end protection comparable to impact guard(s) 
conforming to the requirements of paragraph (g) of this section shall 
be considered to be in compliance with those requirements.

[FR Doc. 98-12753 Filed 5-13-98; 8:45 am]
BILLING CODE 4910-22-P