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Proposed Rule

Truck Length and Width Exclusive Devices

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Information about this document as published in the Federal Register.

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Federal Highway Administration (FHWA), DOT.


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


The FHWA is requesting comments on proposed criteria for excluding safety or efficiency enhancing devices from measurement of vehicle length and width.

All previous interpretations related to exclusions from measurements of vehicle length and width would be superseded to the extent they are inconsistent with these regulations.


Comments must be received on or before November 16, 2000.


Mail or hand deliver comments to docket number 1997-2234, U.S. Department of Transportation, Dockets Management Facility, Room PL-401, 400 Seventh Street, SW., Washington, DC 20590, or submit electronically at​submit. All comments received will be available for examination and copying at the above address from 9 a.m. to 5 p.m., e.t., Monday through Friday, except Federal Holidays. Those desiring notification of receipt of comments must include a self-addressed, stamped postcard or print the acknowledgment page after submitting comments electronically.

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Mr. Tom Klimek, Office of Freight Management and Operations, (202-366-2212); or Mr. Charles Medalen, Office of the Chief Counsel (202-366-1354), Federal Highway Administration, 400 Seventh Street, SW., Washington, DC 20590. Office hours are from 7:45 a.m. to 4:15 p.m., e.t., Monday through Friday, except Federal holidays.

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Section 411(h)of the Surface Transportation Assistance Act of 1982 (STAA) (Public Law 97-424, 96 Stat. 2097) gave the Secretary of Transportation (Secretary) authority to exclude from the measurement of vehicle length any safety and energy conservation devices found necessary for the safe and efficient operation of commercial motor vehicles (CMVs). That authority is now codified at 49 U.S.C. 31111(d). Section 416(b), now 49 U.S.C. 31113(b), authorized similar exclusions when measuring vehicle width. Section 411(h) also provided that no device excluded from length measurement by the Secretary could have, by design or use, the capability to carry cargo.

Since enactment of the STAA, four Federal Register notices have identified some 55 devices as length or width exclusive. Copies of all of them are available on-line under the FHWA docket number cited at the beginning of this document. (See 52 FR 7834, March 13, 1987; 54 FR 52591, December 26, 1989; 55 FR 10468, March 21, 1990; and 55 FR 25673, June 22, 1990.)

Prior to 1979, the FHWA operated under an administrative definition of the term “vehicle” that included the main structure of the vehicle with attachments unless an exception or tolerance was allowed by State law as of July 1, 1956. The width limit for trucks and buses at that time was 96 inches (2.44 meters) on the Interstate System, as established by the Federal-Aid Highway Act of 1956 (Public Law 84-627, 70 Stat. 374, at 381). However, it was the practice of the States to allow certain exceptions to that limit for mirrors, hand holds, and turn signals. The maximum width limit of buses was increased from 96 inches (2.44 meters) to 102 inches (2.6 meters) by the Federal-Aid Highway Act of 1976 (Public Law 94-280, 90 Stat. 425, at 438).

The States' practice of allowing exceptions to the width limit was acknowledged and endorsed in the American Association of State Highway Officials' (AASHO) 1963 “Recommended Policy on Maximum Dimensions and Weights of Motor Vehicles to be Operated Over the Highways of the United States.” Width was defined as follows:

Width: The total outside transverse dimension of a vehicle including any load or load-holding devices thereon, but excluding approved safety devices and tire bulge due to load.

This definition has been part of AASHO, now the American Association of State Highway and Transportation Officials (AASHTO), recommended practice since it was adopted in 1963. The difference between the AASHO/AASHTO recommended policy and the FHWA's administrative interpretation generated inquiries which were answered in a Notice of Interpretation (NOI) published on June 28, 1979 (44 FR 37710). The FHWA adopted the AASHO/AASHTO definition of width and allowed the States to exclude certain safety devices from the measurement of a vehicle's width. These consisted of load-induced tire bulge, rearview mirrors, turn signal lamps, and hand holds for cab entry/egress. A subsequent NOI published on January 2, 1981 (46 FR 32), allowed States to expand the list of safety devices which could extend beyond the 96-inch (2.44-meter) load surface. A final rule published on June 5, 1984 (49 FR 23302) and codified in part 658, reiterated the FHWA's previous policy of allowing States to exclude from vehicle width measurements those safety devices that do not extend more than 3 inches (76 millimeters) from either side. The rule interpreted the 102-inch width limit to include its approximate metric equivalent of 2.6 meters. In addition, it defined length exclusive devises as all non-cargo carrying appurtenances at the front or rear of a CMV semitrailer or trailer whose function is related to the safe and efficient operation of the semitrailer or trailer.

Two additional NOI's on length and width exclusive devices were issued on January 13, 1986, (51 FR 1367) and on March 13, 1987 (52 FR 7834). While these documents remain active, they simply represent FHWA's interpretations of statutory provisions and have no binding regulatory effect, either on the States or the motor carrier industry.

The January 13, 1986, NOI specifically excluded from any length measurement 6-inch and 8-inch (152mm and 203mm) front locking devices (bolsters) and a 12-inch (0.30-meter) rear lift tailgate in the “up” position. The NOI declined to exclude a 7-foot (2.13-meter) front trailer frame extension from length measurements on grounds that it was load bearing, but reiterated that this did not necessarily preclude its use because States could recognize it as a length exclusive device.

The March 13, 1987, NOI held that lift gates not over 24 inches (0.61 meters) from the rear of the trailer in the “up” position, B-train assemblies, and about 35 other devices qualified as length or width exclusive devices. It also provided that the width of a trailer be measured across the sidemost load-carrying structures, support members, and structural fasteners, and that the length of a semitrailer be measured from the front vertical plane of the foremost transverse load-carrying structure to the rear vertical of the rearmost traverse load-carrying structure.

The STAA required States to allow 102-inch (2.6-meter) wide CMVs on the National Network (NN). The NN consists of the Interstate System and other highways designated in 23 CFR part 658, appendix A. Hawaii, however, was allowed to keep its 108-inch (2.74-meter) width limit.

In addition, the STAA set minimum length limitations for semitrailers operating in a truck tractor-semitrailer combination on the NN. The States were required to allow semitrailers with a length of 48 feet (14.63-meters), unless the State allowed a longer semitrailer on December 1, 1982. In that case, the longer length was grandfathered and the State must continue to allow the use of semitrailers up to that length on the NN. A list of grandfathered semitrailer lengths is published in 23 CFR part 658, appendix B.

The minimum length limit for each semitrailer or trailer in a truck tractor-semitrailer-trailer combination was established at 28 feet (8.53 meters), or 28.5 feet (8.69 meters) if in legal operation on December 1, 1982, within an overall length of 65 feet (19.81 meters). States may not limit the overall length of a truck tractor semitrailer, or Start Printed Page 50473truck tractor-semitrailer-trailer combination, on the NN.

Pursuant to its authority under section 411(d) of the STAA, the FHWA designated several CMV combinations with unique characteristics as “specialized equipment” and established length parameters for their operation on the NN. The most common of these specialized vehicles are automobile transporters. Minimum length limits established include 65 feet (19.81 meters) for standard automobile transporters and 75 feet (22.86 meters) for stinger steered units, i.e., the fifth wheel is located on a drop frame located behind and below the rear-most axle of the power unit.

Boat transporters are also allowed the same lengths based on the fifth wheel connection location. In addition, all automobile and boat transporters are allowed cargo overhangs of up to 3 feet (0.91 meters) in front of the truck tractor and 4 feet (1.22 meters) beyond the rear of the semitrailer.

Other combinations considered specialized equipment include truck tractor-semitrailer-semitrailer vehicles with a “B-train” connection, Maxi-cubes, and beverage semitrailers. The length requirements established for these combinations are described in 23 CFR 658.13.

The Intermodal Surface Transportation Efficiency Act of 1991 (ISTEA), Public Law 102-240, 105 Stat. 1914, established a minimum length limit for buses of 45 feet (13.72 meters) on the NN. There are no Federal laws or regulations regarding the length of straight trucks.

The ISTEA also prohibited the States from allowing the cargo-carrying units of CMVs with two or more such units to exceed the length allowed and in actual use on the NN on June 1, 1991. It also provided that the length of the cargo-carrying units is to be measured from the front of the first unit to the rear of the last unit. These provisions did not affect the authority of the Secretary to exclude devices from the measurement of length and width if the vehicles are subject to Federal size requirements.

Today's proceeding was originally initiated through an advance notice of proposed rulemaking (ANPRM) issued on December 26, 1989 (54 FR 52951), which requested information on a series of issues. The comment period, originally established at 90 days, was subsequently extended to August 21, 1990 (55 FR 25673). After considering the comments received in response to the ANPRM, the statutory language on length and width exclusive devices in 49 U.S.C. 31111(d), 31113(b), and developments in the industry since 1990, the FHWA is proposing regulatory changes to 23 CFR part 658. The FHWA is requesting comments on proposed criteria for excluding safety or efficiency enhancing devices from measurement of vehicle length and width.

In 1997, the FHWA rearranged its docket system in accord with the electronic system adopted by the Department of Transportation. A new docket was established to receive the information with the number FHWA Docket 1997-2234. Material previously submitted to Docket Nos. 87-5 and 89-12 was transferred and scanned into FHWA Docket 1997-2234.

Sixty-eight comments were submitted in response to the ANPRM (FHWA Docket Nos. 87-5 and 89-12). Those commenting fell into the following groups: States—17, automobile transporter companies—14, trade associations—6, trailer manufacturers—5, bus and truck manufacturers—4, tarp and tarp hardware manufacturers—3, individuals—3, port authorities—1, carpet manufacturer—1, walkway and platform manufacturers—1, employees union—1, U.S. Government agencies—1, and comments relating to extending the comment period—2. Several respondents commented more than once.

Questions in the ANPRM and Comments from Respondents

The ANPRM asked the following questions:

1. What are the safety and enforcement implications of (1) Requiring that certain categories of vehicle components be included in a length or width measurement; and (2) allowing a blanket exclusion for other devices extending no more than 3 inches (76 millimeters) beyond the outer dimensions of the components that must be included in length and width measurements?

Seven States supported the concept, while seven did not. The Indiana State Police favored a blanket exclusion over a list of specific devices. The KansasDOT felt that all devices should be limited to 3 inches (76 millimeters). The Traffic Division and the State Police of Maine favored a 12-inch (0.30-meter) exclusion for non cargo-carrying devices at the rear of a trailer and an exclusion for devices which do not extend beyond the swing radius in front of a semitrailer or trailer. The Michigan DOT and the Oregon DOT felt that a 3-inch (76-millimeter) width exclusion should cover all devices except turn signal lamps and mirrors. The Minnesota DOT had no objection to a blanket 3-inch exclusion. The Virginia DOT accepted the 3-inch band concept, but preferred specific items over a blanket exclusion. The Florida DOT indicated that the proposal would increase uniformity, but degrade safety. The Georgia DOT felt that no new devices should be excluded. The Iowa DOT pointed out that a 3-inch (76-millimeter) exclusion would effectively legalize a 108-inch width (2.74 meter). The North Carolina Division of Motor Vehicles felt that no exclusion should be adopted for width, but a 24-inch (0.61-meter) length exclusion could be adopted at the front and rear of semitrailers and trailers. The Pennsylvania DOT favored determining excluded devices on a case-by-case basis. The Vermont DOT felt that the 3-inch (76-millimeter) exclusion should only be for safety and not efficiency enhancing devices and that excluded devices should be determined by cooperative State action and not Federal mandates. The Washington DOT opposed the concept, fearing it would encourage wider vehicles.

The U.S. Environmental Protection Agency (EPA) favored the 3-inch (76-millimeter) general width exclusion on each side and also favored allowing up to 8 inches (203 millimeters) on each side [a total of 16 inches overall (406 millimeters)] for energy conserving devices. The 8-inch (203-millimeter) exclusion on each side would apply only on a case-by-case basis in anticipation of new designs in innovative technology.

Five trade associations favored the proposal, as did two trailer and two truck manufacturers. Navistar International Transportation Corporation (NAVISTAR) stated that the 3-inch (76-millimeter) exclusion should extend from the maximum allowable width of a vehicle and not from the actual width of the vehicle, if less.

The Port Authority of New York and New Jersey opposed the proposal because some NN highways in the port area have lanes less than 12-feet (3.66-meters) wide.

Most of the respondents recognized the advantages of a general exclusion over specific exclusions from the measurement of vehicle length and width. Their principal concern was that this would somehow result in longer and wider vehicles. However, the idea that some accommodation must be provided for devices exceeding the maximum vehicle width and length was recognized in the STAA, which gave the Secretary authority to provide exemptions. In addition, the proposed rule specifies that excluded devices must be non-cargo carrying.

2. What other alternatives are there for simplifying the present process for determining which devices should be Start Printed Page 50474included or excluded when measuring the length or width of a vehicle?

Three States responded to this question. The California DOT observed that trailer manufacturers have designed for maximum width, with no allowance for protection of the load or trailer. The Georgia DOT suggested that only safety devices be excluded from width measurements, although both safety and operational devices could be excluded from length. The Nebraska State Patrol suggested that safety devices be clearly defined.

Four motor carrier respondents emphasized that any loss of trailer length or width would be detrimental to them and the economy. The Specialized Carriers & Rigging Association (SC&RA) suggested a general exclusion supplemented by specific exclusions for devices which could exceed the general exclusion. It further suggested an advisory committee to make recommendations to eliminate interpretation problems and determine which devices to exclude from length and width measurements. The American Trucking Associations (ATA) indicated that there was no way to simplify the process, that it should remain on a case-by-case basis. Navistar and Mack Trucks, Inc. (MACK) suggested that safety devices which could extend more than 3 inches (76 millimeters) from the side of a vehicle should be specifically listed. Navistar suggested that access steps should be included as a safety device.

The commenters recognized that unless vehicles were manufactured to include necessary safety and efficiency enhancing devices within maximum width and length limits, some exclusions from the measurement of length and width of vehicles would be necessary.

3. The following are possible categories for components of trailers: (1) Structural (needed to support or convey the load), (2) load protection, (3) protection of trailer components, and (4) vehicle safety. Are there any other categories that would be useful for determining whether a device should be included or excluded from a length or width measurement?

Of the six State DOT's that commented on this question, Missouri and Oregon favored the existing components. Iowa wanted aerodynamic devices to be excluded as a measurable vehicle component, while Minnesota wanted devices for loading and unloading vehicles excluded. California wanted to exclude load protection devices or devices that protect trailer components. Florida wanted to exclude rub rails and vehicular visibility enhancements from components to be measured in determining vehicle length.

The ATA suggested that attempting to specify additional components would only lead to debates over semantics. The SC&RA suggested that trailer components should be considered in four categories: (1) Structural (needed to support or convey the load), (2) load protection, load holding, and load securement, (3) protection of vehicle components, and (4) vehicle, driver, and public safety.

This question may have been confusing. It was intended to determine what components are integral parts of a trailer and should be included in its measurements. While it is clear that structural components should be included in the measurement of trailer dimensions, it appears that the other categories proposed by the SC&RA are not integral trailer components, but are devices to be included as needed. We believe that the proposal to include in the measurement of length and width all components of a vehicle which are not excluded is the simplest and easiest to apply. In addition, this NPRM proposes that an aerodynamic device at the front or rear that is an integral part of a semitrailer or trailer would be included in the measurement of its length unless it is a length exclusive device.

4. How would the proposed approach or an approach offered in response to question number 2 impact: Vehicle manufacturers? Motor carriers? Shippers? Highway operations?

Eight State DOT's and two truck manufacturers commented on this question. Georgia, Oregon, and Virginia recognized that a blanket exclusion would reduce confusion as to what devices were excluded. Florida said that eliminating length or width exclusions would result in reductions in cargo space in order to accommodate devices formerly excluded. California felt that it might need to reevaluate the routes available for large trucks. Iowa, Minnesota, and Nebraska felt that the impact would be unfavorable.

Navistar felt that a 3-inch (76-millimeter) exclusion would allow greater flexibility in designing devices, and Mack felt that the effect would depend on what devices were exempted from the 3-inch (76-millimeter) limit.

The responses to this question were general in nature. There are at least 10 devices which, under current Federal interpretation, may extend up to 3 inches (76 millimeters) beyond the 102-inch (2.6-meter) width of trailers, and States may allow additional safety devices to extend up to 3 inches (76 millimeters). The proposed exclusion is similar but will merely mean that new devices will be automatically excluded and not have to go through a rulemaking process.

5. Under existing Federal regulations, States must exempt specified devices from the measurement of vehicle length and width. They may exempt safety devices that do not extend more than 3 inches (76 millimeters) from the side of a vehicle. Does the problem of determining what new devices should be exempted from length and width measurements warrant further preemption of State authority by requiring them to allow a blanket 3-inch (76-millimeter) exemption?

Ten State DOT's, two trade associations, two truck manufacturers, and one employee union responded to this question. Maine, Minnesota, and Nebraska agreed that a 3-inch (76-millimeter) exclusion was justified. Vermont felt that exclusions should be determined by cooperative State action. Connecticut and Missouri opposed a blanket 3-inch (76-millimeter) exclusion. Virginia felt preemption was justified only if State laws or regulations were unreasonable. Iowa and Georgia were concerned about the safety of a blanket 3-inch (76-millimeter) exclusion. California favored individual over blanket exclusions.

The ATA, SC&RA, Navistar, and Mack favored Federal preemption. The International Brotherhood of Teamsters worried about the safety of trucks growing to 108 inches (2.74 meters).

The commenters generally accepted that some devices must extend beyond the structural elements of a vehicle. Since publication of the 1987 NOI, the 3-inch band for width exclusion has evolved into a national “standard” generally followed by States and the industry.

6. Current regulations provide that the length of a semitrailer and a full trailer is to be measured from the front vertical plane of the foremost transverse load-carrying structure to the rear vertical plane of the rearmost transverse load-carrying structure. Current regulations also provide that the width of a trailer is measured across the sidemost load-carrying structures, support members, and structural fasteners. Should these regulations be clarified and if so, how?


The “regulation” in question 6 was in fact the NOI published on March 13, 1987, which, as stated earlier, represents the FHWA's interpretation of statutory language, but is not binding in its application.

Six State DOT's, two carrier associations, one trailer manufacturer, and the EPA commented. Florida and Iowa felt that no clarification was needed. Oregon suggested that trailer Start Printed Page 50475lengths should be measured “from the front of the foremost structural or load bearing member to the rearmost structural or load bearing member.” It had no comment on how widths should be measured. Georgia and Nebraska felt that the measurements should be from the outermost trailer extremities, and Michigan merely criticized the existing definition.

The EPA said that “cargo carrying structure” is more understandable than “structural element.” Lufkin, a trailer manufacturer, suggested that vehicles should be measured against an imaginary box of legal dimension, while the SC&RA felt the matter should be studied by an advisory committee. The ATA favored a manufacturer's certification that the vehicle was of legal dimensions as a way of taking the responsibility for measurements off field enforcement personnel.

We believe that the proposal to measure all parts of a vehicle, except those excluded from measurement, is the simplest and easiest to apply. Even if the ATA's suggestion was adopted, manufacturers would have to know how to measure a trailer. The concept of measuring against an imaginary box would have pragmatic application problems. Many of the size variances which prompt enforcement action are relatively small with respect to the overall size of the vehicle, i.e., a few inches versus 48-feet long or 8-feet 6-inches wide. It is quite likely that many violations would be missed as a vehicle could appear to be “legal” yet actually be far enough out of “square” to be in violation.

7. There are no regulations on how buses or other commercial vehicles are to be measured. Are they needed? If so, how should they read?

Eleven State DOT's, two carrier associations, one bus manufacturer, and one trailer manufacturer commented.

California and Indiana felt this should be left to the States. Iowa, Minnesota, and Oregon reported no problems measuring buses. Nebraska and North Carolina felt that all CMV's, including buses, should be measured the same. Michigan believes that regulations should be adopted, while Florida believes they are not needed. Virginia suggested that buses should be measured from the front vertical plane to the rear vertical plane. Georgia believes that buses should not exceed 102 inches (2.6 meters) in width except for mirrors.

Lufkin Industries Inc. and Flxible Corporation believe that regulations should be adopted. The ATA favored a manufacturer's certification as a substitute for field measurements, while the SC&RA supported the development of standards by the FHWA for measuring all vehicles.

Section 4006(b)(1) of the ISTEA amended section 411(a) of the STAA [49 U.S.C. 31111(d)] to require States to allow buses up to 45-feet (13.72-meters) long on the NN. The FHWA is proposing to measure buses the same as other vehicles, i.e., including all parts except those excluded from measurement.

Another issue which has developed, specifically with respect to buses, is whether the measured length should include or exclude bumpers. In establishing the 45-foot length requirement for buses, the Congress was silent on the subject. Existing regulatory language is also silent on the issue as the definition of length exclusive devices in 23 CFR 658.5 refers generally to “all appurtenances at the front or rear of a commercial motor vehicle semitrailer, or trailer”. Buses are not specifically mentioned in the definition, yet they are commercial vehicles. The only relevant guidance is that provided in the March 13, 1987, NOI. The drawings included in that document to demonstrate trailer length exclude a “resilient bumper block” at the rear of a semitrailer while including a “non-resilient bumper”.

While revising their statutes to reflect the Federal requirement for 45-foot buses, some States have adopted a limit inclusive of bumpers, some a limit excluding bumpers, and many a 45-foot limit with no further qualification of the issue.

Consistent State-to-State treatment of STAA vehicles is the primary goal of Federal legislation in this area. In recent years, however, different State policies on bus bumpers have caused compliance problems for operators.

For these reasons, this proposal would allow States to exclude from the length measurement of a commercial vehicle, including buses, resilient bumpers up to 6 inches out from the front and rear of the vehicle. Resilient bumpers would include devices made from any material which can be deformed by impact, and substantially return to its original shape immediately upon disengagement with the item impacted. While the genesis of this issue has involved buses, the application to all commercial vehicles will match what is indicated in the NOI of March 13, 1987, and not make illegal any vehicles operating under the 1987 guidance on resilient bumper blocks.

8. Should there be a limit on how far a width exclusive device may extend, if more than 3 inches (76 millimeters), from the side of a vehicle (i.e., rearview mirrors, turn signal lamps, hand holds for cab entry and egress, and splash and spray suppressant devices)? If so, what should the limit be?

Twelve State DOT's, three trade associations, four truck or trailer manufacturers, one bus manufacturer, and one motor carrier responded. Florida, Maine, and Missouri did not support a limit on the length of mirrors. They felt mirrors should be as wide as necessary. Maine said there would be no reason for them to extend further than necessary, and Navistar said that weight, vibration, and aerodynamics would limit the extension of safety devices to no more than necessary. Michigan favored making mirrors retractable. Of these ten commenters, six also would not limit the lateral extension of turn signal lamps.

Indiana favored a 12-inch (0.30-meter) limit for mirrors, 6 inches (152 millimeters) for turn signal lamps, 4 inches (102 millimeters) for hand holds for cab entry/egress, and 3 inches (76 millimeters) for splash and spray suppressant devices. Virginia also favored a 12-inch (0.30-meter) limit for mirrors, provided they were mounted on collapsible holders. California and Minnesota favored a 10-inch (254-millimeter) limit for mirrors. The Port Authority of New York and New Jersey favored an 8-inch (203-millimeter) limit for mirrors, Iowa favored a 6-inch (152-millimeter) limit provided they were a hinged or a breakaway design, Oregon and Nebraska favored a 5-inch (127-millimeter) limit, and Georgia, Missouri, and Central Freightlines favored a 3-inch (76-millimeter) limit. The ATA felt that the length of mirrors should be considered by an advisory committee. The National Truck Equipment Association, SC&RA, Freightliner, Navistar, Mack, Lufkin, and Flxible felt that in addition to mirrors and turn signal lamps, hand holds for cab entry/egress and splash and spray suppressant devices should not be subject to specific length limits.

Rearview mirrors are essential to the safe operation of CMVs. The National Highway Traffic Safety Administration (NHTSA) requires vehicle manufactures to install outside mirrors when the driver of a motor vehicle does not have a clear and reasonably unobstructed view to the rear (49 CFR 571.111). The Federal Motor Carrier Safety Administration (FMCSA) requires motor carriers operating CMVs in interstate commerce to maintain these mirrors (49 CFR 393.80). However, neither the NHTSA nor the FMCSA have requirements concerning the distance the mirror may extend beyond the sides of CMVs. Many commenters to the Start Printed Page 50476ANPRM favored the establishment of a restriction on the distance a review may extend beyond the sides of CMVs, but differing on the value. The distances mentioned ranged from 3 to 12 inches (25.4mm to 0.30 meters). Two commenters suggested that mirrors be of a hinged or breakaway design. No commenters provided support for the distance they suggested, or why hinged or breakaway designs should be required.

The FHWA believes that mirrors must extend far enough from the side of the vehicle to provide a reasonably unobstructed view to the rear of the vehicle, yet not so far that a driver cannot easily adjust the mirror as necessary. Most mirror designs extend more than 3 inches (76 millimeters) beyond the sides of the vehicle, and a 12 inch (0.30-meter) distance was the maximum requested by commenters. The FHWA believes 12 inches (0.30 meter) is a reasonable maximum distance for mirrors to extend from the side of a CMV and is proposing a 12-inch maximum (0.30-meter). There is no safety data to indicate that motor carriers operating CMVs with mirrors extending to the 12-inch distance are having difficulty operating these vehicles on the NN.

9. Are there any devices on trailers manufactured between 1983 and 1987 that would be eliminated by the proposed regulations? If so, what are they? Should they be grandfathered? What should the grandfather date be?

Eight State DOT's, three trade associations, and two trailer manufacturers commented. Florida, Nebraska, Virginia, and the SC&RA said that either there should be no permanent grandfathers or that they were not aware of any. California and Iowa said that no illegal devices should be grandfathered. Georgia, Kansas, and Oregon said that there should be no permanent grandfathers but only equipment grandfathers, and those for not more than 2 or 3 years.

The Truck Trailer Manufacturers Association, Lufkin, and Kolstad Company said that devices on trailers manufactured before any new regulations become effective should be grandfathered. The ATA, who favored self-certification by trailer manufacturers, agreed.

We are unaware, at this point, of any devices that exceed the limits proposed to be allowed. Consideration will be given to grandfathering any devices that are pointed out to us in comments to this NPRM. In addition, any unauthorized new devices that may exceed the limits proposed in this rulemaking may be considered for exclusion from length or width measurement. Sufficient justification should be provided in either case to determine if it would be appropriate to exclude them from the measurement of vehicle length or width.

Miscellaneous Docket Comments

There were miscellaneous comments from several State DOT's. Kansas suggested that regulations for length and width exclusive safety devices should be included in the Federal Motor Carrier Safety Regulations for ease of enforcement. Michigan said that if a long vehicle scraped another vehicle on a turn without the driver being aware of it, leaving the scene of the accident would be a felony offense that could cost the driver his/her license. However, a driver who was unaware of an accident and who had not acted in wanton and willful disregard for the consequences of his/her action would not have the requisite intent to sustain a felony conviction. In any event, this would be true for a vehicle of any length or width.

California, Iowa, and Virginia urged that consideration be given to a hinged or breakaway design for excluded devices. This is unnecessary as excluded devices are not made sturdier than necessary since this would add to the tare weight of the vehicle. Furthermore, inertial forces would render an underdesigned hinged or breakaway design ineffective if a vehicle was moving at more than a minimum speed.

Missouri asked if a 4-foot 11-inch (1.50-meter) front extension on trailers used to haul test vehicles was excluded from length measurement. Automobile transporter combinations are subject to a minimum overall length limit on the NN. States must allow them to be that long but are not required to allow them to be longer. States would have to allow attachments on automobile transporter trailers within the overall length limit provided they were not unsafe.

The ATA, National Industrial Transportation League, Moore's Lumber and Building Supplies, Watkins Shepard Trucking, Inc., Churchill Truck Lines, Inc., and Comcar Industries, Inc., believe that manufacturing, operational, and maintenance tolerances should be adopted. They pointed out that thermal expansion, variations in structural components, and operational bending and twisting could all cause trailers to exceed legal measurements. Also fifth wheel height, differences in suspension components, and tire inflation can all cause trailers to tilt, lean, or both. Repairs, such as external “fish plate” repairs to bottom rails or reinforcements for intermodal operations and side doors, are all necessary for efficient trailer operations.

Since there is no authority in the STAA to exclude structural or load-carrying components from length and width measurements, manufacturing tolerances for these components would be inconsistent with the statute. We will not propose any such tolerance. The alleged need for operational tolerances involving lean, tilt, or twist can be removed by requiring that measurements be made from the same point on each side, or at the front and rear of the vehicle. This is reflected in the proposed regulations.

Structural repairs and reinforcements for side doors or intermodal operations, while incidentally load supporting, have as their primary purpose repairing or adapting trailers to other uses, thereby increasing their efficiency. Therefore, we are proposing to consider structural repairs and structural reinforcements for side doors and intermodal operations as width exclusive devices and allowed to extend 1 inch (25.4 millimeters) on either side of the vehicle beyond the components to be included in width measurements. However, at the locations where these structural reinforcements have been added, the 3-inch (76-millimeters) overall exclusion would still apply to the basic 102-inch (2.6-meters) unit width. The 3-inch (76-millimeters) band would be inclusive of the 1-inch (25.4-millimeter) reinforcement and not additive.

The National Automobile Transporters Association and fourteen individual automobile transporters wanted load-carrying tiedowns or “flippers” to be excluded from length measurements.

The STAA authorized the FHWA to adopt rules to accommodate automobile transporters on the NN. Under that authority, the FHWA required States to allow automobile transporters to be a minimum of 65 feet (19.81 meters) in overall length [75 feet (22.86 meters) if stinger-steered], plus cargo overhangs of up to 3 feet (0.91 meters) in front of the truck tractor and 4 feet (1.22 meters) beyond the rear of the semitrailer. These overhangs are not length exclusive devices, but are simply operating rights created for, and limited to, this specialized equipment. The need for overhangs is an illustration of why the Congress authorized special treatment for these vehicles.

In order to load modern automobiles, many with bodies that extend only a short distance beyond their front and rear axles, to the full extent of the allowed overhangs, automobile Start Printed Page 50477transporters must use retractable platforms to position and secure them. Although not explicity authorized in our existing regulations, their use is consistent with the implementation of regulations allowing cargo overhangs. Therefore, we propose to amend 23 CFR 658.13(e) to clarify that retractable platforms or “flippers” are not to be included in the length determination of automobile transporters when positioning and securing assembled highway vehicles, provided that when being used, the platforms (or flippers) themselves do not extend more than 3 feet (0.91 meters) beyond the front of the auto transporter, or 4 feet (1.22 meters) beyond the rear of the semitrailer. However, when not being used to secure vehicles, they must be retracted since they are not cargo, do not provide a mount for or restrain cargo, and thus serve none of the intended purposes of the overhang provision. It is not necessary to consider if they should be excluded from measurement of the length of automobile transporters plus overhangs since they do not extend beyond the minimum lengths that States must allow.

One automobile transporter who responded to the ANPRM also wanted an exclusion for a step to extend 4 inches (102 millimeters) in front of the front bumper of the cab of automobile transporter vehicles. This would enable the driver to stand on the step while tying down cargo on the power units. The proposed 3-inches (76-millimeter) exclusion would cover such devices. Transporters who believe a 4-inch step surface is necessary could partially recess the step into the bumper to obtain the extra inch of width.

The EPA and one individual wanted the FHWA to establish a point of contact for equipment innovators to learn about length and width exclusions. The Size and Weight Team Leader [currently Mr. Klimek (202-366-2212)] in the Office of Freight Management and Operations is the agency's contact for questions of that kind.

World Carpets wanted up to a 6-inch (152-millimeter) width exclusion on each side of a trailer for bulge due to load. Strick Trailers said that loads, such as carpets, bulk grain, bagged livestock feed, and others press against the side of a trailer and bow it as much as 7.5 inches (191 millimeters). Load-induced bulges in the sides of a trailer are neither safety nor energy conservation devices and therefore are not covered by the proposed exclusion.

A manufacturer of external work platforms for cattle trailers requests exclusion of the platform for safety reasons which will extend 21/2 inches (64 millimeters) from the load bearing vertical trailer ribs when folded in the up position. This platform is included in the proposed exclusion band.

One tarp and tarp equipment manufacturer proposed that no exclusion be allowed for tarps and tarp hardware since its system did not exceed applicable width limits, while two others advocated up to a 5-inch (123-millimeter) exclusion. We believe that tarps, tarp hardware, and complete tarping systems can be accommodated within a 3-inch (76-millimeter) exclusion. This would be the case even if the system being considered included a component piece (e.g., headboard, frame, etc.) of a width equal to that of the vehicle itself plus up to 6 inches. Assuming the component is not also intended or designed to meet the front-end structure requirements of 49 CFR 393.106, and is properly centered as part of the installation process, the net effect would remain that no part of the device would extend beyond 3 inches from the measured width of the vehicle. Also allowed would be transition pieces or “wings” between a front-end structure which is designed to meet the requirements of 49 CFR 393.106 (and limited to 102-inches wide), and the movable portion of a tarping system. However, for these wings to remain eligible for width exclusion, they must: (1) Not extend more than 3 inches (76 millimeter) from the side of the bulkhead, (2) not be attached to any other cargo-carrying or supporting part of the flatbed structure, and (3) remain as an add-on piece as opposed to building a single piece bulkhead up to 108-inches wide. This would apply to tarping systems for open-top trailers that are used (1) to protect the cargo from weather and vandalism, (2) prevent the contents of a vehicle from spilling onto the road, and (3) tarping systems that when deployed enclose the cargo carrying area of a flatbed. All three eliminate the need for drivers to climb onto the vehicle in order to position and fasten these coverings.

Other Issues

Section 411(h) of the STAA reads as follows:

The length limitations described in this section, shall be exclusive of safety and energy conservation devices, such as rear view mirrors, turn signal lamps, marker lamps, steps and handholds for entry and egress, flexible fender extensions, mudflaps and splash and spray suppressant devices, load-induced tire bulge, refrigerator units or air compressors * * *.

Refrigeration units and air compressors are usually mounted on the front of trailers and were, therefore, intended to be length exclusive. All of the rest were intended to be width exclusive.

Rear view mirrors, turn signal lamps, hand holds for cab entry/egress, splash and spray suppressant devices, and load-induced tire bulge have been identified as width exclusive devices in 23 CFR 658.5 but with no limit on how far they may extend beyond the side of a vehicle. The FHWA policy announced in the 1987 NOI allows a 3 inch (76 millimeter) width limit for marker lamps. In addition, prior regulations have not explained how far steps and hand holds for entry and egress, flexible fender extensions and mudflaps may extend beyond the side of a vehicle.

Except for mirrors and turn signal lamps, we believe the lateral extension of all these devices should not exceed 3 inches (76 millimeters). We therefore propose not to provide a specific exclusion for these devices but to leave them subject to the general 3-inch (76-millimeter) width exclusion.

We also propose to apply a general rule to refrigeration units and air compressors, i.e., they will be excluded from measurement of vehicle length insofar as they do not extend beyond the swing radius in front of a semitrailer or trailer. Again, no specific exclusion will be provided. We would be interested in any comments concerning whether this will accommodate the newer refrigeration units which are wider and flatter.

In response to section 414(a) of the STAA, the NHTSA and the FHWA opened companion rulemaking proceedings, the former applicable to new vehicles, the latter to those already in service, to prescribe minimum standards for the performance and installation of splash and spray suppressions devices. Both proceedings were terminated on grounds that no available technology had been demonstrated to reduce splash and spray significantly [53 FR 18860 (FHWA), 18861 (NHTSA), May 25, 1988]. However, the devices tested by the NHTSA did not increase splash and spray, and probably helped to prevent truck tires from throwing gravel and other road debris into the path of other vehicles. Since mudflaps are required by many States, we propose to include within the 3-inch (76 millimeter) blanket exclusion all devices intended to reduce splash and spray or to block or contain debris kicked up by tires.

States may allow a semitrailer or trailer longer than the minimum length required by the STAA to operate on the NN. They may also issue permits allowing vehicles to exceed the 102-inch (2.6 meter) width limit on the NN. Start Printed Page 50478In those cases, the length-and-width-exclusions proposed by this NPRM would not apply: the Federal government does not have jurisdiction to regulate non-STAA vehicles, and the States may impose any conditions they wish on the use of overwidth permits, including complete prohibition of width-exclusive devices. Nonetheless, the Federal Motor Carrier Safety Regulations (in particular 49 CFR part 393, Parts and Accessories Necessary for Safe Operation) generally apply to all CMVs (as defined in 49 CFR 390.5) operated in interstate commerce irrespective of their length or width.

The ISTEA length freeze applies only to cargo-carrying units, not to length exclusive devices which are prohibited from carrying cargo.

Aerodynamic Devices

The 1987 NOI suggests that aerodynamics devices up to 5-feet (1.52 meters) long be excluded from vehicle length measurement. Four individuals wanted an exclusion for aerodynamic devices extending beyond the 5 feet (1.52 meters) and one asked for an exclusion of up to 8 feet (2.44 meters). The discussion in the NOI required that aerodynamic devices not obscure tail lamps, turn signals, marker lamps, identification lamps, license plates or any other required safety devices, such as hazardous materials placards. Regulations published at 49 CFR 393.3 require that any additional equipment or accessories not decrease the safety of operation of the CMVs on which they are attached. This would include the effect of splash and spray on following or passing vehicles, the effect of aerodynamic buffeting on passing vehicles, and any hazards posed by the device if the vehicle on which it was attached was in an accident.

The purpose of aerodynamic devices is to increase fuel economy. We recognize that this is critically important to the Nation's transportation system. However, solid aerodynamic devices or those which include a rigid frame may pose a danger in case of crashes where vehicle underride is a factor.

Because of FHWA's concern about any solid or rigid frame aerodynamic devices being attached to the rear of trailers, such as panels on each side of the rear of the trailer and hinged metal plates extending beyond the rear of the trailer, no exclusions for solid or rigid devices are proposed in this rulemaking. New technological advances would be considered on a case-by-case basis. At a minimum, such requests would have to include sufficient information to demonstrate clearly that they would be safe under all highway conditions that might be encountered.

There are no similar concerns for aerodynamic devices made of flexible material, inflated by air pressure and which have no rigid structure. They would have to comply with 49 CFR 393.3 which requires that any additional equipment or accessories not decrease the safety of the vehicle on which they are attached.

We propose to exclude flexible aerodynamic devices up to 8 feet (2.4 meters) in length from the measurement of vehicle length.

Any aerodynamic device attached to the rear of a vehicle must also comply with the conspicuity requirements.

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 using the docket number appearing at the top of this document in the docket room at the above address. We will file comments received after the comment closing date in the docket and will consider late comments to the extent practicable. We may, however, issue a final rule at any time after the close of the comment period. In addition to late comments, we will also continue to file, in the docket, relevant information becoming available after the comment closing date, and interested persons should continue to examine the docket for new material.

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

We have determined that this action is not a significant regulatory action within the meaning of Executive Order 12866 or significant within the meaning of Department of Transportation regulatory policies and procedures. It is anticipated that the economic impact of this rulemaking will be minimal; therefore, a regulatory evaluation is not required.

Regulatory Flexibility Act

In compliance with the Regulatory Flexibility Act (5 U.S.C. 601-612), we have evaluated the effects of this rule on small entities. The FHWA certifies that this action will not have a significant economic impact on a substantial number of small entities. This action merely replaces a list of specific devices that may extend beyond the structural members of a vehicle with a general rule covering how far devices may extend beyond the structural members of vehicles.

Executive Order 13132 (Federalism)

This action has been analyzed in accordance with the principles and criteria contained in Executive Order 13132, dated August 4, 1999, and it has been determined that this action does not have a substantial direct effect or sufficient federalism implications on States that would limit the policymaking discretion of the States. While aspects of this document directly preempt State law and or regulation, the practical effect is to simply codify what has evolved into standard practice by the States and industry since enactment of the STAA in 1983.

Executive Order 12372 (Intergovernmental Review)

Catalog of Federal Domestic Assistance Program Number 20.205, Highway Planning and Construction. The regulations implementing Executive Order 12372 regarding intergovernmental consultation on Federal programs and activities apply to this program.

Paperwork Reduction Act

Under the Paperwork Reduction Act of 1995 (PRA) (44 U.S.C. 3501, et. seq.), Federal agencies must obtain approval from the Office of Management and Budget (OMB) for each collection of information they conduct, sponsor, or require through regulations. The FHWA has reviewed this proposal and determined that it does not contain collection of information requirements for the purposes of the PRA.

Unfunded Mandates Reform Act of 1995

This rule does not impose a Federal mandate resulting in the expenditure by State, local, and tribal governments, in the aggregate, or by the private sector, of $100 million or more in any one year. (2 U.S.C.1531 et seq.).

Executive Order 12988 (Civil Justice Reform)

This action meets applicable standards in sections 3(a) and 3(b)(2) of Executive Order 12988, Civil Justice Reform, to minimize litigation, eliminate ambiguity, and reduce burden.

Executive Order 13045 (Protection of Children)

We have analyzed this action under Executive Order 13045, Protection of Children from Environmental Health Risks and Safety Risks. This rule is not economically significant rule and does not concern an environmental risk to health or safety that may disproportionately affect children. Start Printed Page 50479

Executive Order 12630 (Taking of Private Property)

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

National Environmental Policy Act

The agency has analyzed this action for the purposes of the National Environmental Policy Act of 1969, as amended (42 U.S.C. 4321 et seq.) and has determined that this action will 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.

Start List of Subjects

List of Subjects in 23 CFR Part 658

  • Grants program—transportation
  • Highways and roads
  • Motor carrier—size and weight
End List of Subjects Start Signature

Issued on: August 11, 2000.

Walter L. Sutton, Jr.,

Federal Highway Deputy Administrator.

End Signature Start Part


In consideration of the foregoing, the FHWA proposes to amend 23 CFR part 658 as follows:

1. Revise the authority citation for 23 CFR 658 to read as follows:

Start Authority

Authority: 23 U.S.C. 127 and 315; 49 U.S.C. 31111, 31112, 31113, and 31114; 49 CFR 1.48.

End Authority

2. Amend § 658.5 by revising the definition of Length exclusive devices and Safety devices—width exclusion and adding a definition of Swing radius to read as follows:

* * * * *

Length exclusive devices. Devices excluded from the measurement of vehicle length. Such devices shall not be designed or used to carry cargo.

* * * * *

Safety devices—width exclusion. Devices excluded from the measurement of vehicle width. Such devices shall not be designed or used to carry cargo.

* * * * *

Swing radius. The swing radius is the volume bounded by the front wall of a semitrailer or trailer and the arc formed when a line centered on the kingpin is rotated from the lower left to the lower right front corner of the vehicles. The swing radius extends from the bottom to the top of the semitrailer or trailer.

* * * * *

3. In § 658.13, remove paragraph (f); redesignate paragraphs (g) and (h) as paragraphs (f) and (g), respectively; and revise paragraph (e)(1)(ii) to read as follows:

* * * * *

(e) * * *

(1) * * *

(ii) All length provisions regarding automobile transporters are exclusive of front and rear overhang. Further, no State shall impose a front overhang limitation of less than 3 feet or a rearmost overhang limitation of less than 4 feet. Extendable ramps or “flippers” on automobile transporters which are used to achieve the allowable 3-foot front and 4-foot rear cargo overhangs are excluded from the measurement of vehicle length, provided they are retracted when not supporting cargo.


4. Amend § 658.15 by removing paragraph (c) and redesignating paragraph (d) as paragraph (c).

5. Add § 658.16 to read as follows:

Exclusions from length and width determinations.

(a) Vehicle components not excluded by law or regulation shall be included in the measurement of the length and width of commercial motor vehicles.

(b) The following shall be excluded from measurements of commercial motor vehicle length and width: All nonload-carrying devices which do not extend more than 3 inches beyond the front or each side of the vehicle, or 24 inches beyond the rear of the vehicle, and all nonload-carrying devices within the swing radius at the front of a semitrailer or trailer. In addition, resilient bumpers extending up to 6 inches from the front and rear of a commercial vehicle shall be excluded from the measurement of length.

(c) Rear view mirrors may extend up to 12 inches and turn signal lamps my extend up to 6 inches beyond each side of a vehicle.

(d) Aerodynamic devices made of flexible material which are inflated by air pressure and lack a rigid structure may extend not more than 8 feet beyond the rear of a vehicle, provided they do not obscure tail lamps, turn signals, marker lamps, identification lamps, license plates, or any other required safety devices, such as hazardous materials placards or conspicuity markings.

(e) These exclusions are specific and may not be added to other excluded devices.

(f) Measurements are to be made from a point on one side or end of a commercial motor vehicle to the same point on the opposite side or end of the vehicle.

End Part End Supplemental Information

[FR Doc. 00-20939 Filed 8-17-00; 8:45 am]