Rhode Island General Laws Title 31. Motor and Other Vehicles § 31-3-2. Vehicles subject to registration

(a) Any vehicle operated upon a highway in conformance with the provisions of the chapters relating to manufacturers, transporters, dealers, lien holders, or nonresidents;

(b) Any vehicle that is operated upon a highway only for the purpose of crossing the highway but not along the highway from one property to another;

(c) Any farm vehicle, whether or not of a type otherwise subject to registration under this chapter, that is only incidentally operated upon a highway. For purposes of this title, the phrase “incidentally operated upon a highway” shall mean the operation upon a highway of a slow-moving motor vehicle that is designed and used primarily as a farm implement for drawing plows, mowing machines, and other implements of husbandry, between agricultural operations owned or managed by the owner of the motor vehicle. Unless the incidental operation is only for purposes of crossing the highway but not traveling along it, the farm vehicle engaged in the incidental operation shall display a “Slow Moving Vehicle” emblem in a manner that complies with requirements established by the division of motor vehicles;

(d) Any special mobile equipment as defined in § 31-1-9;

(e) Any vehicle that is propelled exclusively by electric power obtained from overhead trolley wires, though not operated upon rails.