Interpretation ID: 20588.ztv

Mr. Terry Vos
Tioga, Inc.
850 Florida Avenue South
Golden Valley, MN 55426

Dear Mr. Vos:

We are replying to your fax of August 17, 1999, to Rich Van Iderstine of this agency, on trailer lighting.

You tell us that you manufacture "air heaters used by the construction industry." The assembled unit "is permanently mounted to an axle and hitch that is suitable for highway transport when necessary, to move from job to job." These units "are used at construction sites nationwide," and their rear lamps are easily broken. You have asked "since these are portable machines, rather than cargo trailers, do the same trailer lightings requirements apply . . . or are there some exceptions that may apply" which would permit you to use reflectors rather than lamps.

Under the laws that we administer, a "motor vehicle" must comply with all applicable Federal motor vehicle safety standards, such as the one that specifies requirements for lamps, reflective devices, and associated equipment (Standard No. 108). For this purpose, a "motor vehicle" is defined as a vehicle that is driven or drawn by mechanical power and "manufactured primarily for use on the public streets, roads, and highways." (49 U.S.C. 30102(a)(6)).

Whether we consider your trailer-mounted equipment to be a "motor vehicle" depends on its use. It is our position that this statutory definition does not encompass mobile construction equipment, such as cranes and scrapers, which use the highway only to move between job sites and which typically spend extended periods of time at a single job site. In such cases, the on-highway use of the vehicle is merely incidental and is not the primary purpose for which the vehicle was manufactured. In contrast are instances where vehicles, such as dump trucks, frequently use the highway going to and from job sites, and stay at a job site for only a limited time. Such vehicles are considered "motor vehicles" since the on-highway use is more than "incidental."

If your equipment typically spends extended periods of time at a single job site and only uses the public road infrequently to move between job sites, it would not be considered a "motor vehicle" subject to the Federal motor vehicle safety standards. Assuming this is the case, you may equip the air heater with such lamps and reflectors as you deem appropriate. However, your productwould still be subject to local laws when used on the public roads. If your equipment uses the public roads on more than an incidental basis, it would be considered a "motor vehicle" subject to the Federal motor vehicle safety standards, including Standard No. 108.

If you have any questions, you may phone Taylor Vinson of this Office (202-366-5263).

Sincerely,
Frank Seales, Jr.
Chief Counsel
ref:108
d.11/9/99