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Interpretation ID: 21938


    Mr. Jimmy Biondi
    W.J. Casey Trucking and Rigging Co., Inc.
    1200 Springfield Rd.
    Union, NJ 07083


    Dear Mr. Biondi:

    This is in response to your recent correspondence and telephone inquiries relating to the classification of certain specialized vehicles owned by your company.

    You ask whether the individual units are motor vehicles and therefore subject to safety standards administered by this agency.

    As discussed below, the answer to your question appears to be yes. The National Highway Traffic Safety Administration (NHTSA) issues safety standards for "motor vehicles." Section 30101(a)(6) of Chapter 301 of Volume 49 of the United States Code defines "motor vehicle" as:

      any vehicle driven or drawn by mechanical power manufactured primarily for use on the public streets, roads, and highways, except any vehicle operated exclusively on a rail or rails.

    You describe the vehicles as hydraulic suspension trailers that consist of a series of axles linked through a common hydraulic system in either a two, three, or four axle configuration. The individual units can be used alone or may be joined together depending on the load to be carried. The units have a minimum of 2 axles per unit with 8 tires per axle and have a maximum load of 34 metric tonnes (33.46 tons) per axle. The axle units are 10 feet wide and support a flat deck. Each axle is steerable and the hydraulic suspension may be adjusted while the vehicle is in motion in order to ensure that the deck remains level even when the unit is traveling over an uneven surface.

    You further indicate that these vehicles are to be used for the short distance transport of unusually large cargo to and from rail sidings, utility substations and shipping ports. Your letter indicates that when empty, the modules are trucked to the work site on trailers and then assembled in the configuration needed for the work at hand. You further state that when the units are to be used on a site that is "local," the modules would be configured at your site and the resulting trailer would be towed to the site where it is to be loaded. In a telephone conversation, you also indicated that with the exception of the two axle units, an individual unit or module would travel empty on the highway en route to a location where it would be loaded.

    In your letter, you stated that the trailer is always accompanied by company escorts and state police as required by permits. You also indicate that the maximum travel speed is 40 miles per hour empty and usually less than 20 miles per hour when the trailer is loaded. We assume that your use of these trailers is consistent with the intentions of the manufacturer.

    Based on the information you provided, it is our opinion that the vehicles you describe are motor vehicles for the purposes of Chapter 301 and Federal motor vehicle safety standards. As you indicated in your letter and telephone conversation, all of the units will travel on public highways at speeds above 20 miles per hour. Furthermore, such operation would not be incidental to their main use but would be part of the normal use and operation of the vehicles.

    As the trailers are motor vehicles, they are subject to the requirements of Chapter 301. Section 30115 of Chapter 301 (49 U.S.C. 30115) requires that the manufacturer must certify that a vehicle meets all applicable Federal motor vehicle safety standards and, in the case of a vehicle, must permanently affix a certification label or tag to the vehicle. For your information, I have enclosed an agency guide for trailer manufacturers which provides guidance on the safety standards applicable to trailers.

    We note, however, that due to the unusual configuration of these trailers, they would not be required to conform to several Federal motor vehicle safety standards that are applicable to more conventional trailers.

    For example, Standard No. 224, Rear impact protection, requires most trailers and semitrailers weighing over 10,000 pounds to be fitted at the rear with a rear impact (underride) guard meeting the requirements of Standard No. 223, Rear impact guards (49 CFR 571.223 and 571.224, published on January 24, 1996, at 61 FR 2004). However, certain kinds of vehicles are excluded. The only excluded categories that are relevant for the purposes of this letter are wheels back vehicles and low chassis vehicles. Wheels-back vehicles are excluded by S3 of Standard No. 224, Rear impact protection. The term is defined in S4 as a "trailer or semitrailer whose rearmost axle is permanently fixed and is located such that the rearmost surface of [the tire] on that axle is not more than 305 mm forward of the transverse vertical plane tangent to the rear extremity of the vehicle."

    The drawing you enclosed of the trailer owned by your company shows that the rear surface of the tires on that axle is within 305 mm of the rear extremity. Assuming the axle is "permanently fixed," this is a wheels back vehicle, and no guard is required.

    We also note that your trailers appear to be excluded from the requirements of Federal Motor Vehicle Safety Standard (Standard) No. 121, Air Brake Systems (49 Code of Federal Regulations (CFR) 571.121). Standard No. 121 applies to trucks, buses, and trailers equipped with air brake systems. However, subparagraphs S3(a) through (g) of Standard 121 lists seven types of vehicles to which the standard does not apply. Applicable to your trailer, paragraph S3(a) excludes any trailer that has a width of more than 102.36 inches with extendable equipment in the fully retracted position and is equipped with two short track axles in a line across the width of the trailer. Similarly, S3(e) excludes any trailer that has a GVWR of more than 120,000 pounds and whose body conforms to that described in the definition of heavy hauler trailer set forth in S4

    Heavy hauler trailer is defined in S4 as:

    [A] trailer which has one or more of the following characteristics, but which is not a container chassis trailer:

      (1) Its brake lines are designed to adapt to separation or extension of the vehicle frame; or

      (2) Its body consists only of a platform whose primary cargo-carrying surface is not more than 40 inches above the ground in an unloaded condition ...

    The drawings that you have provided indicate that the trailers at issue are 118 inches wide and have two short track axles under the trailer deck. Accordingly, these trailers are, by virtue of S3(a) of Standard No. 121, not required to meet the requirements of Standard No. 121. The information attached to your letter also indicates that the trailers have a GVWR exceeding 120,000 pounds and that the cargo-carrying surface of the trailer bed is less than forty inches above the ground. If so, S4(a)(2) applies and, when combined with the trailer's GVWR, excludes your trailer from the ABS requirements in accordance with S3(e) of Standard No. 121.

    I hope this information is helpful to you. Should you have any further questions or need additional information, please feel free to contact Mr. Otto Matheke at this address or at (202) 366-2992.

    Sincerely,

    John Womack.
    Acting Chief Counsel

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    d.3/22/01