Stephen E. Selander, Esq.
    Senior Counsel
    Warner Norcross & Judd LLP
    2000 Town Center, Suite 2700
    Southfield, MI   48075-1318

    Dear Mr. Selander:

    This responds to your request for an interpretation whether your client’s (Morbark’s) products, portable brush chippers, are "motor vehicles" for purposes of the National Traffic and Motor Vehicle Safety Act, including the TREAD Act. We will identify the relevant factors that should be considered in making such determinations.

    Title 49 U.S.C. Chapter 301 authorizes the National Highway Traffic Safety Administration (NHTSA) to prescribe Federal motor vehicle safety standards (FMVSSs) applicable to new motor vehicles and new items of motor vehicle equipment. Section 30102(a)(6) defines "motor vehicle" as:

    "[A] vehicle driven or drawn by mechanical power and manufactured primarily for use on the public streets, roads, and highways, but does not include a vehicle operated only on a rail line."

    We have issued a number of interpretations of this language. We have stated that vehicles equipped with tracks, agricultural equipment, and other vehicles incapable of highway travel are not motor vehicles. We have also determined that certain vehicles designed and sold solely for off-road use (e.g., airport runway vehicles and underground mining vehicles) are not motor vehicles, even if they may be operationally capable of highway travel. Finally, we have concluded that items of mobile construction equipment that use the highways only to move between job sites and that typically spend extended periods of time at a single site are not motor vehicles. However, we do consider vehicles that use the public roads on a necessary and recurring basis to be motor vehicles.

    You provided information about several models of brush chippers. You write that: "Eight of the models have axles, tires and wheels, and can be easily moved around a site or from site-to-site by towing."

    You stated that Morbark believes that its portable brush chippers are not covered by the Vehicle Safety Act or the TREAD Act. You stated that Morbark brush chippers are designed primarily for use off-highway in helping to clear sites of trees and brush by chipping the brush, tree limbs, and small tree trunks.

    You also stated that Morbark believes that its portable brush chippers are not trailers as defined in 49 CFR 571.3. That regulation defines trailer as "a motor vehicle with or without motive power, designed for carrying persons or property and for being drawn by another motor vehicle."

    We have reviewed the videotape you enclosed with your letter. We note that in some instances, the Morbark brush chipper and vehicle towing the chipper were depicted as parked on the side of the road in what appears to be a residential area. We also understand from the information you provided that some of these products are used by tree service and landscape companies. We have also reviewed information provided at Morbark’s web site:

    Whether Morbark’s portable brush chippers are considered motor vehicles under the National Traffic and Motor Vehicle Safety Act depends on their use, i.e., whether they typically spend extended periods of time at a single site or, by contrast, use the public roads on a necessary and recurring basis. By way of example, in a letter to DuraTech dated June 4, 1997, we took the position that mobile tub grinders are not motor vehicles because they stay on job sites for extended periods of time (usually for months and very rarely for less than a week). Similarly, we have concluded that mobile waterjet cutting and cleaning equipment was not a motor vehicle, based on the fact that it appeared to stay on job sites for extended periods of time ranging from a week to over a year.

    We do not have information concerning the specific usage patterns of each of Morbark’s brush chippers to determine whether they are motor vehicles. Moreover, while we seek to be helpful in providing opinions about our statutes, we do not have the resources to provide a detailed review of the products of each company. However, if the brush chippers use the public roads on a necessary and recurring basis, they would be motor vehicles. We would think that would likely be the case for at least some of Morbark’s portable brush chippers, since tree service and landscape companies would tow the portable brush chippers by trucks to jobs, park them along the curb during work, and then tow them to the next job or, at the end of the day, return them to the company’s facilities. Tree service company crews commonly complete one to two jobs per day. We also note that, in a letter to Lindig Manufacturing Corporation dated January 5, 1984, we took the position that brush chipper trailers are motor vehicles.

    As to your question concerning the definition of trailer, we would consider the brush chipper itself  to be the property being transported.

    I have enclosed a fact sheet entitled "Information for New Manufacturers of Motor Vehicles and Motor Vehicle Equipment." I hope this information is helpful. If you have any further questions, please feel free to contact Dorothy Nakama of my staff at this address or by telephone at (202) 366-2992.


    Jacqueline Glassman
    Chief Counsel