49 U.S.C. § 20301: Definition and nonapplication

(a) Definition.—In this chapter, “vehicle” means a car, locomotive, tender, or similar vehicle. (b) Nonapplication.—This chapter does not apply to the following:(1) a train of 4-wheel coal cars. (2) a train of 8-wheel standard logging cars if the height of each car from the top of the rail to the center of the coupling is not more than 25 inches. (3) a locomotive used in hauling a train referred to in clause (2) of this subsection when the locomotive and cars of the train are used only to transport logs. (4) a car, locomotive, or train used on a street railway.