Federal Motor Vehicle Safety Standards Rear Impact Guards; Rear Impact Protection

DEPARTMENT OF TRANSPORTATION

National Highway Traffic Safety Administration

49 CFR Part 571

[Docket NHTSA-98-3342, Notice 1]

RIN 2127-AA43

Federal Motor Vehicle Safety Standards Rear Impact Guards; Rear

Impact Protection

AGENCY: National Highway Traffic Safety Administration (NHTSA),

Department of Transportation (DOT).

ACTION: Final rule; response to petitions for reconsideration;

technical amendment; denial of petition to extend the effective date.

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SUMMARY: On January 24, 1996, NHTSA published a final rule establishing

an equipment standard for underride guards and a vehicle standard which

requires the installation of guards meeting the equipment standard on

the rear end of heavy trailers and semitrailers. In response to

petitions for reconsideration, NHTSA is amending that final rule to:

clarify the 100 mm (4 inch) height requirement for the horizontal

member of an underride guard, explicitly exclude from having to meet

the energy absorption requirements all cargo tank motor vehicles

manufactured with rear end protection complying with the high strength

requirements of 49 CFR part 178 (to protect hazardous material) that

occupies the area specified for NHTSA's underride guard, and increase

the acceptable range of force application rates during testing. The

agency is also excluding pulpwood trailers from the application of the

vehicle standard and denying a petition from the Truck Trailer

Manufacturer's Association (TTMA) for an extension of the effective

date of the final rule.

DATES: The amendments made by this rule will become effective on

January 26, 1998. Petitions for reconsideration of this rule must be

received no later than March 12, 1998.

ADDRESSES: Any petitions for reconsideration should refer to the docket

number and number of this notice and be submitted in writing to:

Administrator, National Highway Traffic Safety Administration, Room

5220, 400 Seventh Street, SW, Washington DC, 20590.

FOR FURTHER INFORMATION CONTACT: The following persons at the National

Highway Traffic Safety Administration, 400 Seventh Street, SW,

Washington, DC, 20590:

For non-legal issues:

Dr. George Mouchahoir (Telephone: 202-366-4919) or Mr. Michael

Huntley (202-366-0029), Office of Crashworthiness Standards

For legal issues:

Mr. Paul Atelsek, Office of the Chief Counsel (202-366-2992), e-

mail: [email protected]

SUPPLEMENTARY INFORMATION:

I. Background

On January 24, 1996, the National Highway Traffic Safety

Administration (NHTSA) published a final rule promulgating two new

Federal Motor Vehicle Safety Standards (FMVSS) to require upgraded rear

impact guards (underride guards) on trailers and semitrailers (61 FR

2004).\1\ The first standard (No. 223, Rear impact guards) specifies

performance requirements for strength and energy absorption for the

underride guards themselves. This standard also contains a

configuration requirement that the horizontal cross member of the guard

be at least 100 mm (4 inches) high at any point across the guard width.

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\1\ Although both trailers and semitrailers are equally affected

by the rule, they will sometimes be referred to simply as

``trailers'' in the remainder of this document.

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As issued in January 1996, the standard requires testing the guards

for strength by pushing with a 203 mm by 203 mm (8 inch by 8 inch)

force plate at specified points along the horizontal member of the

guard. The test continues displacing the force plate at a constant rate

of between 1.0 and 1.5 mm/sec (0.04 and 0.06 inches/sec) in a forward

direction, as the guard is oriented on the trailer, until the guard

resists a specified force, or until 125 mm (5 inches) of displacement

occurs. To pass, the guard has to resist the specified force within the

first 125 mm (5 inches) of displacement.

The standard's test for energy absorption is conducted by applying

a force in the same way as in the test for strength, but only at one

specified test point. The force is recorded at least ten times per 25

mm (1 inch) of displacement until the 125 mm (5 inch) displacement is

reached and the force plate is completely withdrawn from the guard. The

guard energy absorption is calculated from a force vs. deflection

diagram plotted using the recorded measurements. Only plastic

deformation (permanent deformation) is counted toward meeting the

required amount of energy absorption--elastic rebound of the guard does

not count.

The second standard (No. 224, Rear impact protection) requires most

new trailers and semitrailers with a Gross Vehicle Weight Rating of at

least 4,536 kg (10,000 pounds) to be equipped with a rear impact guard

meeting the requirements of the equipment standard. This standard also

specifies requirements for the location of the horizontal member of the

guard relative to the rear end of the trailer or semitrailer, including

a requirement that the rearmost surface of the member be located no

more than 305 mm (12 inches) forward of the trailer's rear extremity.

Certain types of trailers, including pole trailers and ``wheels-back''

vehicles, are excluded from the application of this rule.

The January 1996 final rule on truck underride protection specified

an effective date of January 26, 1998 and a March 11, 1996 deadline for

receiving petitions for reconsideration on this rule.

II. Petitions for Reconsideration

NHTSA received five petitions for reconsideration of the final rule

from companies in the trailer and semitrailer equipment and

manufacturing industries. In addition, one letter was received from an

insurance group.

The Insurance Institute for Highway Safety (IIHS) did not request

any change to the rule. IIHS's letter sought to clarify what IIHS

considered a misunderstanding (i.e., undercounting) on NHTSA's part

regarding the potential number of lives saved as a result of the final

rule. IIHS stated that this clarification was needed if the agency is

to decide on future rulemaking actions on rear underride for single-

unit trucks or side underride for large trucks. NHTSA has met with IIHS

staff to discuss their views on how best to estimate potential lives

saved, and made adjustments in its data collection efforts to improve

the quality of its data on underride crashes. The letter was not

labeled as a petition and will not be addressed further.

One of the petitioners was Rite-Hite Corporation which manufactures

``dock locks,'' safety restraint equipment that is mounted on loading

docks to secure trailers to the docks during loading and unloading.

Rite-Hite requested that the agency modify the configuration and

strength specifications of the guard to be compatible with its dock

locks. It stated that the requirements of the final rule directly

affect the ability of its dock locks to safely engage and hold trailers

to the loading docks. The Rite-Hite loading dock device uses a hook

that wraps around and over the rear protection guard to help prevent

guards from riding up and over the restraining barriers, and to help

prevent incidents

[[Page 3655]]

that can result from trailer tip-over and landing gear collapse. Rite-

Hite estimates that 100,000 of these dock locks currently exist.

Rite-Hite asked NHTSA to comment on the role of its final rule with

regard to limiting civil tort liability. Rite-Hite states that some

vehicle manufacturers and others in the industry consider the final

rule to be the sole factor to be considered in designing underride

guards. It requested that the agency clarify that compliance with the

final rule does not by itself insulate any manufacturer of rear impact

guards from all civil tort liability. It also urged NHTSA to state that

guard and trailer manufacturers must also take into account other

safety issues, such as loading dock uses of rear impact guards, in

making appropriate and reasonable design choices that are consistent

with the final rule.

Rite-Hite also petitioned for several changes to specific

provisions of the final rule. It requested NHTSA to change the minimum

cross sectional vertical height requirement in S5.1 of Standard No.

223, which currently specifies that ``[t]he horizontal member of each

guard shall have a cross sectional vertical height of at least 100 mm

[4 inches] at any point across the guard width'' (emphasis added). Some

manufacturers are manufacturing guards with horizontal members that are

100 mm (4 inches) high on both the front and back sides of the

horizontal member. Rite-Hite is concerned because the vehicle restraint

may not engage properly in certain circumstances (e.g., abnormally high

horizontal member, guard located forward of the rear extremity, poor

alignment of the vehicle with the dock, and bumpers affixed to the

horizontal member). It is also concerned that the restraint's warning

light may not indicate the failure to engage without being modified.

To address this potential problem, Rite-Hite petitioned NHTSA to

either: (1) Specify 4 inches as the maximum height, (2) change the

regulatory language to restrict the height specification to the rear-

facing side of the horizontal member, or (3) insert an interpretation

that the existing language applies only to the rear-facing side of the

horizontal member and an advisory that some vehicle restraint

manufacturers recommend forward-facing surfaces be about 1.25 inches

high.

Rite-Hite also requested NHTSA to modify S5.2.1 of Standard No. 223

to increase the minimum guard strength at location P2 (in the center of

the guard, where Rite-Hite's dock locks attach). It stated that,

because many vehicle restraints will provide 2-3 times more holding

power than the guard strength requirement of the rule (50,000 N, or

11,240 lb), guard strength is not sufficient to withstand the forces

encountered during premature trailer pull-out from loading docks.

Therefore, Rite-Hite petitioned the agency to increase the minimum

force at test point P2 (where dock locks typically attach) to

approximately 150,000 N (33,370 lb).

Rite-Hite requested that the test procedures of S6.6 of Standard

No. 223 be amended so the guard would have to meet similar strength

requirements when pushed in a rearward direction (i.e., in the opposite

direction from the striking vehicle) as it has to meet when it is

pushed forward.

Rite-Hite requested that NHTSA delete the exclusion from Standard

No. 224 for ``wheels-back vehicles.'' These are vehicles on which the

rear tires are fixed at a position within 305 mm (12 inches) of the

rear extremity of the trailer. Rite-Hite suggested that there will be

an increase of loading dock incidents without an underride guard to

secure the rear of the trailer to the dock. It also argued that wheels-

back vehicles with wide-spaced single tires and no underride guard

would increase the chance of passenger compartment intrusion,

presumably by allowing the striking vehicle to penetrate between the

tires.

Rite-Hite also requested that the horizontal member of the guard,

and of hydraulic guards in particular, not be permitted, as it

currently is, to extend rearward of the rear extremity of the vehicle.

The company is concerned about damage to the dock locks, the dock

walls, the underride guard itself, and with the dock lock not properly

engaging. It is also concerned that rear-extending guards will prevent

the trailer from backing up flush with the dock, creating a gap between

the trailer bed and the loading dock, even with a dock lock engaged.

Rite-Hite states that this gap could cause loss of ``lip purchase'' of

loading dock levelers on the bed of the trailer, and personal injury to

loading dock employees. Rite-Hite also asked that NHTSA clarify that

hydraulic guards must meet the dimensional and guard strength

requirements for non-hydraulic guards.

To ensure adequate engagement with dock locks, Rite-Hite also

requested that the horizontal member be restricted to a position no

more than 2 inches forward of the trailer rear extremity, rather than

the currently permitted 305 mm (12 inches).

Rite Hite wants the agency to specify a minimum horizontal guard

member height of 457 (18 inches) above the ground. It is concerned that

lower heights might not adequately engage the dock locks and might

increase the chances of the guards being damaged by road surfaces and

falling off.

Finally, Rite Hite requested NHTSA to prohibit a sloped surface on

the forward side of the rear impact guard and require a vertical

surface there instead. Rite Hite states that the sloping surface will

depress all kinds of vehicle restraints designed to hold on to the

underride guard, thus causing disengagement.

TTMA petitioned the agency to define ``cargo tank motor vehicle''

and make it clear that any vehicle so constructed would not have to

meet the energy absorption requirements of the rule. It stated that the

``present definition of a special purpose vehicle defines a cargo tank

motor vehicle excluded by Standard No. 224 by its operational

characteristics, namely, hazardous material held in transit, instead of

by its construction characteristics.'' It noted that cargo tank motor

vehicles are required by 49 CFR 178.345-8(d) 2 to have very

strong rear end protection to protect the cargo tank and its piping in

the event that another vehicle impacts it from the rear. TTMA argued

that a manufacturer cannot design a guard to meet both the extreme

rigidity requirements of 49 CFR 178.345-8(d) and the energy absorption

(yielding) requirements of S5.2.2 of Standard No. 223.

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\2\ These rules are administered by the Department of

Transportation's Research and Special Programs Administration

(RSPA).

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Great Dane Trailers, Inc. (Great Dane) petitioned the agency to

increase the permissible range of force application during the strength

and energy absorption tests. It stated that the current requirement to

maintain a constant rate of between 1 mm and 1.5 mm per second (60 mm

and 90 mm per minute) ``may require expensive and sophisticated

equipment'' and that the rate of displacement is not a significant

indicator of the performance of the guard. Great Dane suggested

changing the requirement to specify a rate that ``averages not less

than 1 mm and not more than 25 mm per second over each 25 mm of

displacement.''

Great Dane also requested that the minimum energy absorption test

be amended to double the displacement of the horizontal member of the

guard. Great Dane stated that its current guards do not respond by

plastic deformation until 75 mm (3 inches) of displacement has been

achieved, and that stopping the test at 125 mm (5 inches) of

displacement, as currently specified,

[[Page 3656]]

will require it to weaken the guards to meet the requirements. Great

Dane petitioned to displace the guard to 250 mm (10 inches), thus

ensuring more plastic deformation of the guards and increasing the

energy absorption to 2-3 times the desired minimum. Great Dane

subsequently forwarded test data that it believed supported its

request.

STRICK Corporation (STRICK), a trailer manufacturer, also expressed

concern over the need to purchase expensive precision testing equipment

to replace their current devices. In its testing, STRICK found it

``impossible to determine the exact displacement for each and every

second over the time of the test.'' STRICK petitioned to change the

requirement from maintaining a constant rate of displacement between 1

mm and 1.5 mm per second band to a requirement of ``displacement rate

of the force is approximately constant over a time of 1 to 5 minutes''.

STRICK is basically requesting a slower force application (i.e., more

time, which would be required with a slower pump) to reach the 125 mm

(5 inch) required displacement. STRICK also argued that the

``displacement requirement'' in the final rule was inserted without

adequate notice and represents a major change from the proposal.

Finally, James King & Co. (King) petitioned the agency to amend the

rule to require that rear truck underride guards protect from damage

the reflective conspicuity markings required by Standard No. 108,

Lamps, reflective devices, and associated equipment. King has observed

that few manufacturers have provided the protective measures that NHTSA

had suggested that manufacturers could take (e.g., mounting the

reflective material in a steel channel or placing small metal beads

above and below the reflective stripe). As a result, King believes

that, contrary to the agency's assumptions, the majority of markings

are damaged after a short time in use. King did not suggest a

particular solution.

III. Response to Petitions

NHTSA agrees with Rite Hite that mere compliance with NHTSA's

vehicle safety standards does not insulate any guard or trailer

manufacturer from civil liability. 49 U.S.C. 30103(e) explicitly states

``[c]ompliance with a motor vehicle safety standard * * * does not

exempt a person from liability at common law.'' NHTSA's standards are

minimum standards that specify a floor, not a ceiling, for performance.

They are intended to allow manufacturers flexibility in the selection

of means of compliance. Designers of underride guards and trailer

manufacturers that install them are free to consider the non-highway

safety implications of their designs, including the functioning of the

guards with existing dock locks.

The agency also agrees with Rite Hite that the standard currently

does not specify where, within its longitudinal cross section, the

horizontal member of the guard must have a vertical height of 100 mm (4

inches). Some guard manufacturers are apparently misinterpreting that

provision as requiring a 100 mm (4 inch) height across the entire

longitudinal cross section, from front to back.

However, this reading is more design restrictive than the agency

intended, and is not necessary for safety purposes. The 100 mm (4 inch)

minimum height is intended to assure adequate engagement with and

crushing of the frontal vehicle structure by preventing ``knife-

edging'' by a guard that is too thin. In the final rule, the agency

concluded that this objective would be achieved by any guard with a 100

mm (4 inch) cross sectional height that is forward of the rear

extremity by not more than 305 mm (12 inches). The requirement in S5.1

of Standard No. 223 for a cross sectional vertical height of 100 mm (4

inches) does not need to be met in any specific transverse vertical

plane. The important relationship is the distance between the trailer

rear extremity and the forwardmost point at which at least 100 mm (4

inches) of guard height would be engaged by a colliding vehicle.

Given the preceding statement, Rite Hite's proposed changes to the

regulation would unnecessarily restrict guard configuration. For

example, it would be too design restrictive to require that the 100 mm

(4 inch) cross section be measured at the rearmost point on the

horizontal member, as Rite Hite suggests. This would be equivalent to

saying that the guard must have a 100 mm (4 inch) vertical face at the

rear. Although this design is common and probably the best at assuring

immediate engagement, some manufacturers might prefer to use tubular

designs for the horizontal member. Tubular designs would not comply

with Rite Hite's suggested amendment, because the rearmost surface

would be a line rather than a 100 mm (4 inch) high plane. Nevertheless,

a tubular horizontal member would assure adequate engagement. It would

also be too design restrictive to require that the cross section be

vertical. Some shapes without vertical transverse cross sections of the

required height might provide superior engagement or crash dynamics.

For example, some guards might be shaped with sloped rear surfaces to

account for the guard pivoting during a crash. As long as the

horizontal projection of the horizontal member on a vertical plane

presents a 4-inch high profile, then the desired objective will

generally be achieved.

The agency is concerned about the development of certain untested

guard shapes, however. As previously stated, most current guard designs

have a vertical face with a 100 mm (4 inch) minimum height at the first

point of contact for an underriding vehicle. This configuration

provided good protection for passenger vehicle occupants in the NHTSA's

tests. The non-design-restrictive requirements should not imply

encouragement of the development of horizontal members with convex

cross sections at the rear. For example, some manufacturers might want

to design guards with angular, or lens-shaped, cross sections to

achieve better aerodynamic properties. The quality of engagement of

such guard shapes with the underriding vehicle has not been evaluated.

The agency is also concerned that portions of the horizontal member

necessary for adequate engagement might be located more than 305 mm (12

inches) forward of the vehicle's rear extremity. For example, on a

guard with a 100 mm (4 inch) high tubular horizontal cross member whose

rearmost surface is located the full 305 mm (12 inches) forward of the

trailer rear extremity, a full engagement of the guard's horizontal

member will not occur until it has advanced 305 mm (12 inches), plus

the 25 mm (2-inch) radius of the tube. In some cases, engagement might

come too late to prevent passenger compartment intrusion. The purpose

of the requirement in S5.1.3 of Standard No. 224 regarding the location

of the guard's rearmost surface is to assure that full engagement is

achieved as early in the crash event as possible, but in any case

before the passenger vehicle has penetrated more than 305 mm (12

inches) under the trailer. Therefore, NHTSA is amending S5.1 to require

that the vertical height requirement be met by the horizontally

projected height of the horizontal member of the guard on a transverse

vertical plane, and that the guard manufacturer's installation

instructions or procedures specify that the forwardmost part of the

horizontal member necessary to meet this requirement must be located no

more than 305 mm (12 inches) forward of the rear extremity of the

vehicle.

The agency denies Rite-Hite's request to eliminate the wheels back

vehicle exclusion in S3 of Standard No. 224, as it applies to the

single-tire wheels back

[[Page 3657]]

trailers, because the agency does not have enough information on these

vehicles at this time. However, NHTSA is concerned with the possibility

that some smaller passenger vehicles could fit between the tires of

these trailers. In this case, the passenger vehicle might advance past

the rear extremity of the trailer by 305 mm (12 inches) before reaching

the rearmost point on the rear tires, and then advance an additional

distance approximately equivalent to the radius of these large tires,

before contacting the axle. This distance, combined with the subsequent

crush of the front end of the passenger vehicle, might allow passenger

compartment intrusion. The agency appreciates Rite-Hite's concern about

the lack of guards leading to an inability to engage dock locks. NHTSA

notes that the rule does not prohibit ``partial'' guards in between the

wheels of wheels back trailers. Manufacturers of excluded vehicles may

install partial or full underride guards if they consider it essential

to engage loading dock restraint devices.

NHTSA requested data from TTMA on trailers and semitrailers with

single rear tires. TTMA was able to confirm that these vehicles exist

and provided a picture of one, but had no further information on hand.

The agency also has little information on these vehicles, their tire-

to-tire spacing, or their uses. Therefore, NHTSA currently has

insufficient information to determine whether the wheels back exclusion

should continue to apply to these vehicles or whether partial guards

might be appropriate. The agency is planning to begin collecting data

within the National Automotive Sampling System starting in the summer

of 1998 to define the scope of this potential problem. When NHTSA has

gathered the appropriate information, it will consider whether a

rulemaking is warranted to address the issue of single-tire wheels back

vehicles.

NHTSA denies the remainder of Rite-Hite's requests. These requests

appear to be intended to ensure that guards are required to be

compatible withRite-Hite's particular dock lock design. Although NHTSA

is also interested in ensuring the safety of loading dock workers, the

requested changes all tend to restrict underride guard design and

reduce manufacturer flexibility that NHTSA considers essential to the

practicability of the rule. Not all trailers and semitrailers use

loading docks. Further, NHTSA understands that there are dock lock

designs that do not require underride guard design restrictions. If

trucking companies want maximum compatibility with all types of dock

locks, including Rite-Hite's, there is nothing in NHTSA's rule to

prevent them from ordering, or to prevent manufacturers from designing,

underride guards exactly as Rite-Hite suggests.

For the same reason that NHTSA is granting Rite-Hite's request to

clarify that the cross-sectional vertical height requirement need not

be met at the forward-facing surface of the horizontal member of the

guard, the agency denies Rite-Hite's request to prohibit sloping

surfaces or to require a maximum height of 1.25 inches on that surface.

Because there are no vehicle safety benefits related to the shape and

size of the forward-facing surface, it would be unnecessarily design

restrictive to impose certain geometries or height requirements on that

surface. Regardless of the geometry, Rite-Hite's petition indicates

that manufacturers can adapt the forward-facing surface to be

compatible with dock locks by attaching a \3/4\ inch metal bar to the

bottom of the forward-facing surface. Standard No. 223 does not

prohibit this approach.

The agency also denies Rite-Hite's request to modify S5.2.1 of

Standard No. 223 to require the guard's strength at location P2 be

increased to approximately 150,000 N (33,370 lb). A guard strong enough

to withstand the forces encountered when drivers attempt to pull out

while still locked to the dock is not necessary for crashworthiness.

This request pertains to the strength of the guard in the opposite

direction (i.e., rearward) from the one specified in the final rule.

The rule specifies a minimum strength to withstand forces in the

forward direction, such as would result from an underriding vehicle.

The rule does not regulate the requested aspect of performance, and

regulating it would not serve the purpose of the rule. For the same

reasons, the agency denies Rite-Hite's request that S6.6 of Standard

No. 223 be amended so there is a rearward direction force application

test in addition to the specified forward direction test. NHTSA again

notes that there is nothing in the rule to prevent guard manufacturers

from designing guards as Rite-Hite suggests, with 150,000 N (33,370 lb)

strength in the rearward direction.

The agency denies Rite-Hite's request to amend the language of

S5.1.3 of Standard No. 224 to prohibit the horizontal member of the

guard from extending rearward of the transverse vertical plane tangent

to the rear extremity of the vehicle. NHTSA expects that manufacturers

will not design, and trucking companies will not order, underride

guards for uses that will damage loading docks, dock locks, loading

dock levelers, and the guards themselves. NHTSA is aware of some

trailer and semitrailer applications for which a guard extending

rearward of the trailer rear extremity is useful. These applications do

not use loading docks. In addition, rearward mounting is useful in

preventing underride and passenger compartment intrusion by the rear of

the passenger vehicle. The agency does not want to prohibit these

benefits for the sake of regulating the unlikely occurrence of

excessively rearward guard location. For the same reasons, Rite-Hite's

request that ``hydraulic guards not hinge rearward of the transverse

vertical plane tangent to the rear extremity of the vehicle'' is

denied. NHTSA notes that hydraulic guards are already required to meet

the same dimensional and strength requirements as non-hydraulic guards.

NHTSA denies Rite-Hite's request to prohibit positioning the guard

more than 2 inches forward of the trailer rear extremity. This would

eliminate nearly all of the fore-aft flexibility that the agency

believes that manufacturers need in positioning their guards, merely

because a distance more than 50 mm (2 inches) will not be compatible

with Rite-Hite's restraint. NHTSA emphasizes that the final rule

specified mounting the guard within a range of 305 mm (12 inches) or

less, and as close to the rear extremity as practical. This requirement

is probably sufficient to ensure that the vast majority of trailers and

semitrailers are compatible with Rite-Hite's needs. Nearly all guards

are currently being mounted flush with the trailer rear extremity.

NHTSA does not believe that the final rule will change that practice.

If a certain kind of guard is needed for safely docking with dock

locks, trucking companies will presumably specify such guards in their

orders for new vehicles. This would be an additional factor making

change unlikely.

NHTSA denies Rite-Hite's request that S5.1.2 of Standard No. 224 be

amended to prohibit mounting guards with the horizontal member lower

than 457 mm (18 inches) from the ground. The possibility of guard

damage, along with the extensive comments received from the public on

ground clearance, were discussed at length in the preamble of the

January 1996 final rule. The comments indicated that it would be

impractical to mount the guards much lower than the maximum clearance

of 560 mm (22 inches) anyway. The agency does not expect vehicle

manufacturers to mount guards at heights at which the guards or the

vehicles would be damaged due to operational restrictions (e.g.,

railroad crossings). In addition,

[[Page 3658]]

higher costs of lower guards and the difficulty of meeting the strength

requirements at lower heights are additional factors that will keep

most manufacturers from producing guards that are lower than the

maximum height. Therefore, setting a minimum clearance requirement is

unnecessary. Assuming manufacturers did want to produce them for uses

with fewer operational restrictions, lower guards would be safer in a

crash. NHTSA has no evidence that loose guards are falling off and

creating a highway hazard. Regulation is not necessary in this area.

The agency agrees with TTMA that the current language of Standard

No. 224's definition of ``special purpose vehicle'' might be

interpreted to exclude cargo tank motor vehicles due to their

operational use, rather than their construction characteristics. The

rule defines special purpose vehicles as having ``work-performing

equipment (including any pipe equipment that would hold hazardous

materials in transit * * *) 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 * * *'' The phrase ``that

would hold hazardous materials'' might, in the case of a cargo tank

motor vehicle, imply that the exclusion depends on the intentions or

subsequent actions of the purchaser of the cargo tank motor vehicle.

Although manufacturers generally know that trailer owners willing to

pay for a trailer certified to RSPA's standards are planning to

transport hazardous materials, the manufacturer of a cargo tank motor

vehicle should not be charged with the responsibility for determining

what its use will be after it is out of the manufacturer's control.

Therefore, as the TTMA requested, the agency is deleting the phrase

in the definition of special purpose vehicle that explicitly recognized

pipe equipment that would carry hazardous material as work performing

equipment. Piping that carries hazardous materials would still be

considered work-performing equipment, as would any other piping that

needs to occupy the area of the guard while the vehicle is in transit.

However, piping carrying hazardous materials would probably not be

located in such an exposed location, because RSPA's regulations (e.g.,

178.345-8, 178.338-10) generally require that such piping be protected

by RSPA's vehicle rear end protection device or rear

bumper.3

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\3\ Both terms are used to refer to underride guard-type devices

in RSPA's regulation. ``Rear-end protection device'' is used in 49

CFR 178.345, while ``rear bumper'' is used in 49 CFR 178.337 and

178.338. These terms are used below when discussing cargo tank motor

vehicles, both to avoid confusion and to emphasize the different

primary purpose they serve--protecting hazardous material in the

tank, rather than protecting colliding vehicle occupants with crash

protection.

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The standard still needs to be revised to prevent conflict with

RSPA's rule. The high strength requirements for cargo tank motor

vehicle rear end protection devices or rear bumpers in RSPA's

regulations are incompatible with NHTSA's energy absorption

requirement. NHTSA intended to apply only the configuration and

strength requirements, but not the energy absorption requirements, to

vehicles meeting RSPA's requirements with rear-end protection device or

rear bumpers in the area specified by NHTSA for the underride guard.

NHTSA's strength requirements are far lower than RSPA's, so meeting

NHTSA's strength requirements will not be a problem for hazardous

materials cargo tank motor vehicles. The agency stated in the final

rule (at 61 FR 2023) that:

RSPA's rule for underride guards on hazardous materials tankers

(49 CFR Part 178.345-8) is generally compatible with this rule, and

this rule applies to hazardous materials tankers. However, to

prevent any confusion as to the relationship between RSPA's rule and

NHTSA's rule, this rule explicitly recognizes that piping that

carries hazardous materials while in transit needs the special

protection that is provided by RSPA's rule.

Explicitly recognizing vehicles with the pipe equipment in the area

of the guard as special purpose vehicles did not capture within the

exclusion all the vehicles that must be excluded. Any tanker built to

conform to RSPA's regulations with a rear-end protection device or rear

bumper in the area specified for NHTSA's underride guard cannot

practically comply with NHTSA's energy absorption requirement,

regardless of whether it has pipe equipment in the area of the guard or

whether the pipe equipment passes through the area where the guard

could be located.

Therefore, NHTSA is adding a paragraph to the Application section

of Standard No. 224 explicitly excluding all cargo tank motor vehicles

built to RSPA's standards, including insulated cargo tanks and tanks

that carry compressed gases, from the requirement to meet the energy

absorption requirements of S5.2.2 of Standard No. 223, if the rear-end

protection device or rear bumper is in the area specified for NHTSA's

underride guard.

The agency is stating the exclusion more broadly than the TTMA

suggested. The TTMA petitioned to add a definition for a cargo tank

motor vehicle, which referenced some (but not all) of RSPA's tanker

specifications. In NHTSA's view, the benefits of energy absorption for

the striking vehicle are outweighed by the additional danger to that

and other vehicles from spillage of hazardous cargo, so that all

tankers that might be carrying hazardous materials should be excluded

from the energy absorption requirement. RSPA occasionally adds cargo

tank motor vehicle specifications and may also add vehicle rear end

protection device or rear bumper specifications to its regulations. If

the rule referenced RSPA's regulations for every specific tanker and

guard type, every change to the RSPA regulations would necessitate a

corresponding change to Standard No. 224's application section. Due to

the difficulty of coordinating interagency rulemakings and effective

dates, the rule simply references the part of RSPA's regulations that

specifies cargo tank motor vehicles and rear end protection devices or

rear bumper requirements, and excludes from the energy absorption

requirements of this rule all cargo tank motor vehicles that comply

with that part and have a rear end protection device or rear bumper in

the area specified for the underride guard. Any future changes by RSPA

to its tanker guard requirements will likely be made to this part, and

would be automatically incorporated by reference in Standard No 224.

The agency notes that this exclusion from the energy absorption

requirements for RSPA guards on cargo tank motor vehicles applies only

when the RSPA rear end protection device or rear bumper occupies the

space specified for the horizontal member of the NHTSA guard and meets

the configuration and strength requirements specified for the NHTSA

guard. For example, many cargo tank motor vehicles have a rear end

protection device or rear bumper located several feet off the ground.

The guards on these trailers are not excluded from NHTSA's energy

absorption requirement of Standard No. 223.

The requests of Great Dane Trailers and STRICK Corporation

regarding the rate of force application in the tests for strength and

energy absorption can be treated together. NHTSA agrees that changing

the displacement rate requirements in S6.6(a) of Standard No. 223 to

accommodate concerns about the practicability of the test procedure

would not affect the intent of the rule or the determination of the

guard's strength. The objective of the requirement is to assure that

the guard

[[Page 3659]]

is being tested quasi-statically because the specified test procedure

is not a dynamic test.

The specified rate of displacement during force application (1.0 to

1.5 mm/s) may be narrow and too restrictive to accommodate slow-pumping

force application equipment. NHTSA accepts Great Dane's and STRICK's

assertions that new and expensive equipment would be required for those

companies to achieve this rate. More powerful hydraulic pumps are

required to achieve higher rates of displacement during the test,

especially with stronger guards. The agency has no information on how

powerful STRICK's pumps are, but NHTSA chose the quasi-static test

procedure at least in part to accommodate small trailer manufacturers

that presumably have less sophisticated equipment. For steel, the most

common guard material, the rate of force application, within reasonable

bounds, should not make a significant difference in the test results.

For reasons that seem inconsistent with the basis for their

requests, both companies asked for an increase in the permitted

displacement rate. The agency denies these requests. Great Dane

requested an increase in the upper limit of the specified range from

1.5 mm/sec to 25 mm/sec, and STRICK requested an increase to 2.08 mm/

sec. At a displacement rate of 25 mm/sec, a 125 mm (5-inch) test

displacement would be completed in a very short duration of about 5

seconds. This is a very fast force application and conflicts with the

intent of the rule to specify a quasi-static, not a dynamic, test

procedure. Moreover, Great Dane's proposed rate of 25 mm/s would

require high precision and sophisticated computer-controlled test

equipment as well as powerful and efficient pumps--potentially

representing upgraded equipment that both companies state they want to

avoid. The agency notes that NHTSA's Vehicle Research and Test Center

(VRTC) successfully performed its testing program for the subject final

rule using manually-controlled test equipment with no special

instrumentation. Less sophisticated equipment with lower pump capacity

requires more, not less, test duration. The current upper limit on the

rate of displacement during force application of 1.5 mm/sec is being

retained. This should not present a problem for Great Dane or STRICK,

because lower displacement rates can also be selected on more capable

equipment.

Regarding the lower bound for displacement rate, the agency

believes that 6.3 minutes is adequate time to achieve the required

displacement without the need for sophisticated control equipment and

powerful pumps. No petitioner has requested a longer period and, unless

the agency is presented with evidence of a problem with this rate, it

will consider longer periods as unnecessarily prolonging certification

and compliance testing. As explained earlier, reasonably slower

displacement rates will probably not make a significant difference in

test results anyway. Therefore, NHTSA is granting part of STRICK's

request and widening the specified displacement rate range to allow

displacement rates as low as 0.33 mm/sec. Testing at this rate will

allow a 125 mm (5 inch) test displacement to be achieved in a period of

about six minutes.

The range of force displacement rate will now be specified in

centimeters and minutes rather than in millimeters and seconds, i.e.,

as 2.0 cm/minute to 9.0 cm/minute. This range replaces the currently

specified range of 1.0 to 1.5 mm/sec (6.0 to 9.0 cm/minute). The larger

distance per time period is easier for most people to visualize. It is

NHTSA's understanding that the displacement rate on most modern test

equipment (and on all the equipment NHTSA would use for compliance

testing) is controlled by a computer with a feedback system capable of

quickly and automatically adjusting the displacement rate. However, for

purposes of certification testing on non-computer controlled equipment,

precise adjustment is impractical. Specifying the distance on a per-

minute time scale will allow for practical adjustments of the rate of

displacement within each minute. This change would result in a more

practical test procedure and should not compromise the performance

requirements of the rule. The language of section 6.6(a) of Standard

No. 223 is changed accordingly.

The word ``constant'' has been eliminated from the test procedure

as a modifier of the displacement rate. As Great Dane pointed out, the

term ``constant'' is confusing because it is so absolute. The concept

of tolerance, for purposes of compliance testing, has been introduced

as explained below.

Normally, when NHTSA specifies a range in the test conditions of

its standards, the equipment being tested is expected to meet the

specified performance requirements when testing at any point within the

range. In this case, the agency is allowing a broader range of

displacement rates (with a significantly slower rate of displacement at

the lower end of the range) than was allowed originally, to accommodate

the manufacturers' desire to conduct certification testing with their

existing equipment. Applying the usual procedure, NHTSA could test and

expect compliance at any rate within the wider displacement rate range.

However, this would have the effect of making it more, not less,

difficult for manufacturers to certify compliance, because the same

requirements would have to be met under a wider range of conditions.

The agency notes again that tests within the new range of displacement

rates should yield similar results to tests within the old range

because the performance of most current guard materials is not rate

sensitive even over this broader range of load application rates.

Because merely granting the petitioner's request would not achieve

the petitioner's objective of making certification testing easier,

NHTSA will allow the guard manufacturer to designate the displacement

rate, within the range of 2.0 to 9.0 cm/minute, on which it based its

certification. If compliance tests are conducted by the agency, the

manufacturer's designated rate, plus or minus 10 percent, will be used.

The practical effect of this is that the guard must comply at the

designated rate as well as any rate within 10 percent above or below

that rate. As noted above, having to maintain a ``constant'' designated

displacement rate would make it practically impossible for the agency

to conduct compliance testing. For the same reason, NHTSA will not

attempt to duplicate during compliance testing the deflection/time

curve that the manufacturer experienced during certification testing.

As long as the agency stays within the 10 percent tolerance during the

entire test, the compliance test will be valid. If the manufacturer,

for whatever reason, does not designate a displacement rate, NHTSA may

pick any rate within the specified range.

NHTSA denies Great Dane's request to amend the energy requirement

to require twice as much displacement for the purpose of the energy

absorption test. The petitioner stated that the ``current limit of 125

mm will require guards which are weaker (less stiffness) be installed

merely to meet the energy absorption level of 5650 J.'' This amendment

would have the effect of allowing stiffer guards by displacing the

guard 250 mm (10 inches) instead of 125 mm (5 inches) before measuring

to determine whether the guard absorbed the minimum 5,650 joules (4,170

ft-lbs) of energy. The greater displacement would make it easier for

the required plastic deformation of the guard to occur. However, the

point of the energy absorption requirement is to prevent

[[Page 3660]]

overly stiff guards. It would enhance crash safety if manufacturers

weaken guards that are too stiff, because this will allow a softer

``crash pulse'' for the colliding passenger vehicle by ``riding down''

the speed over a short distance during the crash.

Moreover, NHTSA notes that the data that Great Dane submitted in

support of this request does not indicate that any change is needed in

the standard. The test data provided by Great Dane show that the guards

they tested displayed more than twice the required energy absorption

when tested according to the current requirement of 125 mm (5 inches)

of displacement.

Finally, the agency denies King's request to amend the final rule

to include requirements that rear underride guards protect conspicuity

markings from damage. The Federal Highway Administration (FHWA) has

jurisdiction over trailers after the first sale for purposes other than

resale and regulates the maintenance of required safety equipment.

Section 393.11 of the Federal Motor Carrier Safety Regulations (FMCSRs)

requires that commercial motor vehicles meet the requirements of

Standard No. 108 in effect at the time the vehicle was manufactured (49

CFR 393.11). Since December 1, 1993, Standard No. 108 has required new

trailers to meet conspicuity requirements. Accordingly, motor carriers

are currently required under FHWA regulations to maintain the

conspicuity treatments on these trailers. This includes maintaining the

conspicuity treatment on the horizontal member of the underride guard.

On April 14, 1997, FHWA issued an NPRM (62 FR 18170) that would

amend the FMCSRs at 49 CFR 393.11, Lighting Devices and Reflectors, to

make certain that all motor carriers operating trailers subject to the

FMCSRs are aware of their responsibility to maintain the conspicuity

treatments in all locations required by Standard No. 108. However, FHWA

requested comment on whether an exemption from the maintenance

requirement for the tape on the underride guard should be provided due

to practicability problems.4 NHTSA has forwarded King's

comment to FHWA for consideration. Irrespective of whether FHWA

continues to require motor carriers to maintain the conspicuity

treatment on the guards, NHTSA encourages manufacturers to design the

treatment to be as durable as practicable to ensure that the safety

benefits of applying the treatment to that location are realized.

---------------------------------------------------------------------------

\4\ ``The [FHWA Notice of Proposed Rulemaking] does not,

however, include an exemption to the requirement that motor carriers

maintain the conspicuity 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.'' 62 FR 18172-73.

---------------------------------------------------------------------------

If FHWA requires the conspicuity treatment on the horizontal member

of the guard to be maintained, and sufficiently durable conspicuity

treatments are not available, NHTSA assumes that manufacturers would

design guards with channels or other protective features for the

conspicuity treatment. There is nothing in Standard No. 223 that would

prevent such designs. NHTSA will consult with FHWA on whether NHTSA

rulemaking to mandate physical protection for conspicuity treatment is

needed after FHWA completes its rulemaking.

IV. Response to TTMA Petition on Extension of Effective Date

In an April 18, 1997 letter, TTMA petitioned NHTSA to commence

rulemaking to extend the effective date from January 26, 1998 to a date

at least nine months after this response to the petitions for

reconsideration is issued. It stated only that trailer manufacturers

were reluctant to complete the designs of their guards and test these

guards until the petitions were answered.

TTMA's petition for an extension of the effective date is denied.

NHTSA does not see any reason why manufacturers can not complete and

test their guard designs in the allotted time. Except for a few of Rite

Hite's requests, all the petitions dealt with relatively minor issues

of testing and clarification. Manufacturers should have been planning

to comply with the rule as it was published in January of 1996.

The guards that will be required on January 26, 1998 are very

similar to guards currently being produced. NHTSA made no amendments

requiring configuration changes in its responses to the petitions. The

change to the regulatory text relating to vertical cross-sectional

height is basically a clarification of the current requirements. There

were only two minor changes to the test procedures (allowing a more

flexible force application rate and allowing the manufacturer to

designate the force application rate on which it based its

certification). These changes will make it easier for manufacturers to

test the guards and to comply with the requirements. The guards that

manufacturers will be required to produce after this rule is issued

will be essentially the same guards that NHTSA required in the January

1996 final rule. NHTSA notes that the TTMA's Recommended Practice,

``Rear Impact Guard and Protection'' is virtually identical to the

NPRM, except for the energy absorption requirement of Standard No. 223.

This Recommended Practice is designated RP No. 92-94, and was

originally issued in April of 1994 and revised in November of 1994.

Apparently it has been adopted as an industry standard, so little

reengineering should be necessary to meet Standard No. 223. Therefore,

NHTSA believes that the manufacturers have had sufficient time to

complete their designs prior to the January 26, 1998 effective date. A

general extension is not warranted.

However, the agency will consider petitions for temporary exemption

from Standard No. 224. The agency has received a number of these

petitions from small-volume trailer manufacturers within the past few

months. Under 49 CFR 555.6(a), a manufacturer whose yearly production

is not more than 10,000 units may ask for a temporary exemption from a

Federal motor vehicle safety standard for up to three years on the

basis that compliance would cause it substantial economic hardship and

that it has attempted in good faith to comply with the standard from

which it has asked to be excused. Part 555 requires the agency to

publish a notice in the Federal Register seeking public comment on each

exemption petition before a decision can be made on such a request, and

then publish a second notice either granting or denying the petition.

NHTSA expects to issue final decisions on these petitions approximately

three to four months after the date of submission of the petition.

V. Technical Amendment on Logging Trailers

The Application section (S3) of Standard No. 224 currently excludes

``pole trailers'' from the application of the rule. Pole trailers are

trailers with a single, longitudinal telescoping pole, rather than a

normal trailer chassis, connecting the front wheels to the back wheels.

Pole trailers are predominantly used by the logging industry to

transport logs. They spend a great deal of their time off-road at

logging sites and on rough logging roads. NHTSA proposed to exclude

these vehicles in the January 8, 1981 NPRM (46 FR 2139), stating:

the proposed rule does not apply to pole trailers. The agency

believes that requiring underride guards on such vehicles would

provide little benefit to car occupants. Since the poles carried by

these trailers normally overhang the back end of the vehicles for a

considerable distance, the danger of

[[Page 3661]]

underride is due not to the structure of the trailer but to the

structure of the cargo.

This was not a controversial exclusion and it was retained in the 1992

Supplemental Notice of Proposed Rulemaking (SNPRM) and the 1996 final

rule without comment.

Changes in the trailer design and in the logging industry since

1981 have led to a decline in the popularity of pole trailers and the

emergence of ``pulpwood trailers'' to take their place. Pulpwood

trailers are similar in use and structure to pole trailers, but they

have more structure (often two poles or beams) connecting the front

wheels to the back wheels. NHTSA has recently become aware, through an

April 25, 1997 letter from Mr. Buck Ford, that some manufacturers of

pulpwood trailers are deciding how to install underride guards to

comply with the January 1996 final rule, but that other manufacturers

are completely unaware of the rule. Pulpwood trailers are not currently

excluded because they are not technically pole trailers. According to

Mr. Ford, there may be a shortage of pulpwood trailers in 1998 due to

few manufacturers being able to meet the requirements.

NHTSA intended to exclude all trailers that, like pole trailers,

lack structure for attaching guards and that would carry loads likely

to overhang the rear of the trailer substantially when it published the

January 1996 final rule. Pulpwood trailers do not differ significantly

from pole trailers in their construction or use. They also carry

overhanging logs that would negate the value of the underride guard and

operate on rough logging roads on which an underride guard would be a

serious impediment. Due to the lack of controversy regarding the

exclusion of pole trailers, and due to the lack of comment from

pulpwood trailer manufacturers, the agency assumed that the language of

the exclusion covered all trailers of this type.

Because this appears to have been an incorrect assumption, NHTSA is

adding pulpwood trailers to the list of excluded vehicle types. This is

being done by technical amendment because the agency's intent to

exclude vehicles that carry this kind of load was clear from the 1981

NPRM's rationale for the exclusion. This technical amendment will also

avoid a shortage of pulpwood trailers needed by the logging industry in

1998. NHTSA is adopting the pertinent part of the language contained in

Standard No. 121, Air Brake Systems, which defines ``pulpwood trailer''

as ``a trailer 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 * * *''.

VI. Effective Date

The agency finds that there is good cause to make this rule

effective immediately. These amendments do not impose any new

requirements. Instead, they relieve some of the testing burden imposed

on the manufacturers by the January 24, 1996 final rule. It will be

slightly easier for manufacturers to test using the new load

application rates specified in these amendments. These amendments also

make it clear that pulpwood trailers are an excluded category of

vehicle, and that cargo tank motor vehicles built to RSPA's standards

with a rear-end protection device or rear bumper in the area specified

for NHTSA's underride guard do not have to meet the energy absorption

requirements of Standard No. 223. A delayed effective date would impose

a needless compliance burden on the trailer industry, including many

small businesses that manufacture trailers.

VII. Rulemaking Analyses and Notices

A. Executive Order 12866 (Federal Regulation) and Regulatory Policies

and Procedures

This rulemaking action was reviewed under Executive Order 12866.

The action has been determined to be ``not significant'' under

Executive Order 12866 and under the Department of Transportation

regulatory policies and procedures. The Final Regulatory Evaluation

(FRE) for the January 1996 final rule describes the economic and other

effects of that rule in detail.

The responses to these petitions for reconsideration and this

technical amendment do not alter the costs or benefits of that rule

significantly. They merely clarify the intended application of the rule

and provide more flexibility in the test procedures. They do not change

the requirements enough to significantly alter the performance or the

price of rear underride guards. Therefore, a regulatory analysis is not

warranted.

B. Regulatory Flexibility Act

NHTSA analyzed the potential impacts of the January 1996 final rule

on small entities under the Regulatory Flexibility Act and certified

that it would have a significant economic impact on a substantial

number of small entities. NHTSA has described those possible impacts in

the FRE to the January 1996 final rule, which was, in part, a

regulatory flexibility analysis.

The responses to these petitions for reconsideration and this

technical amendment slightly increase manufacturer flexibility in

testing, but NHTSA certifies that the changes made by today's rule do

not have a significant economic impact on a substantial number of small

entities. Most of the changes are interpretations and clarifications of

the existing language, not changes in requirements that impose new

burdens. The changes in requirements are designed to make the guards

easier for manufacturers, especially small businesses, to test their

guards, not to change the guard performance. As a result, some

businesses that otherwise would have had to buy sophisticated testing

equipment or change their guard designs unnecessarily will not need to

do so. Therefore, there will be no new significant impact on small

businesses.

C. Executive Order 12612 (Federalism)

NHTSA has analyzed this rule in accordance with the principles and

criteria contained in E.O. 12612, and has determined that this rule

will not have sufficient federalism implications to warrant the

preparation of a Federalism Assessment.

This rule makes only minor changes to the January 1996 final rule

which had only minimal federalism implications. Nearly all States

require underride protection guards for heavy trailers and

semitrailers. Further, most states require that the guards meet certain

configuration requirements, or that they be positioned in a certain

location relative to the rear and sides of the vehicle. The January

1996 final rule will preempt State requirements for rear impact

protection. However, the agency believes that federalism implications

will be minor because the guards required by that final rule are not

fundamentally different from those required by State law. Several

States, including Michigan, North Carolina, New York, and New Jersey,

already require trailers longer than 15 m (50 ft) to have guards with

the configuration required by that rule. For practical purposes, the

only effect that that rule will have in these States is to require the

guards to be tested and certified for strength and energy absorption.

NHTSA believes that effective rear impact protection measures can

be implemented only at the national level. Only vehicle manufacturers

can produce trailers and semitrailers with improved rear impact

protection. The improvements required by the January 1996 final rule

will cause vehicle manufacturers and operators to incur costs that

could affect their competitive

[[Page 3662]]

position if compliance were voluntary and attempted by some, but not

all manufacturers. That rule applies uniformly to all manufacturers and

will ensure that the competitive position of the manufacturers will not

be significantly affected by the required safety improvements.

D. Preemptive Effect and Judicial Review

Under 49 U.S.C. Sec. 30103(b), whenever a Federal motor vehicle

safety standard is in effect, a State may not adopt or maintain a

safety standard applicable to the same aspect of performance which is

not identical to the Federal standard. 49 U.S.C. Sec. 30161 sets forth

a procedure for judicial review of final rulemaking establishing,

amending, or revoking Federal motor vehicle safety standards. That

section does not require submission of a petition for reconsideration

or other administrative proceeding before parties may file suit in

court. This final rule does not have any retroactive effect.

E. Paperwork Reduction Act

In accordance with the Paperwork Reduction Act of 1980 (P.L. 96-

511), there are no new requirements for information collection

associated with this response to petitions for reconsideration and

technical amendment.

List of Subjects in 49 CFR Part 571

Imports, Incorporation by reference, Motor vehicle safety, Motor

vehicles, Rubber and rubber products, Tires.

PART 571--FEDERAL MOTOR VEHICLE SAFETY STANDARDS

In consideration of the foregoing, 49 CFR part 571 is amended as

follows:

1. The authority citation for part 571 continues to read as

follows:

Authority: 49 U.S.C. 322, 30111, 30115, 30117 and 30166;

delegation of authority at 49 CFR 1.50

2. Sections S5.1 and S6.6(a) of 49 CFR 571.223 are revised to read

as follows:

Sec. 571.223 Standard No. 223; rear impact guards

* * * * *

S5.1 Projected Vertical Height. The horizontal member of each

guard, when viewed from the rear as it would be installed on a trailer

pursuant to the installation instructions or procedures required by

S5.5 of this standard, shall have a vertical height of at least 100 mm

at each point across the guard width, when projected horizontally on a

transverse vertical plane. Those installation instructions or

procedures shall specify that the guard is to be mounted so that all

portions of the horizontal member necessary to achieve a 100 mm high

projected vertical height are located not more than 305 mm forward of

the vehicle's rear extremity, as defined in S4 of 49 CFR 571.224, Rear

Impact Protection. See Figure 1 of this section.

* * * * *

S6.6 Force Application.

* * * * *

(a) Using the force application device, apply force to the guard in

a forward direction such that the displacement rate of the force

application device is the rate, plus or minus 10 percent, designated by

the guard manufacturer within the range of 2.0 cm per minute to 9.0 cm

per minute. If the guard manufacturer does not designate a rate, any

rate within that range may be chosen.

* * * * *

3. In Sec. 571.224 section S3 is revised and section S4 is amended

by adding a definition of pulpwood trailer and revising the definition

of Special purpose vehicle to read as follows:

Sec. 571.224 Standard No. 224; rear impact protection

* * * * *

S3. Application. This standard applies to trailers and semitrailers

with a GVWR of 4,536 kg or more. The standard does not apply to pole

trailers, pulpwood trailers, special purpose vehicles, wheels back

vehicles, or temporary living quarters as defined in 49 CFR 529.2.

If a cargo tank motor vehicle, as defined in 49 CFR 171.8, is

certified to carry hazardous materials and has a rear bumper or rear

end protection device conforming with 49 CFR part 178 located in the

area of the horizontal member of the rear underride guard required by

this standard, the guard need not comply with the energy absorption

requirement (S5.2.2) of 49 CFR 571.223.

S4. Definitions.

* * * * *

Pulpwood trailer means a trailer 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.

* * * * *

Special purpose vehicle means 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 underride guard, as defined by S5.1.1 through

S5.1.3.

* * * * *

Issued on: January 20, 1998.

Ricardo Martinez,

Administrator.

[FR Doc. 98-1783 Filed 1-21-98; 2:18 pm]

BILLING CODE 4910-59-P