Oregon Revised Statutes Oregon Vehicle Code § 801.285

(a) To support and move a permanent load in the form of equipment or appliances constructed as part of or permanently attached to the body of the vehicle;

(b) For transportation of equipment or appliances that are ordinarily kept on or in the vehicle in order that the vehicle may be used for its primary purpose; and

(c) Except for the transportation of permanent load, appliances and equipment described in paragraphs (a) and (b) of this subsection, for purposes other than for the transportation of persons or property over public highways or streets.

(a) A travel trailer.

(b) A tow vehicle, including a tow vehicle with cranes, hoists or dollies.

(c) A truck-mounted transit mixer.

(d) A self-propelled mobile crane.

(a) Air compressors, air drills, asphalt plants, asphalt spreaders, bituminous plants, bituminous mixers, bituminous spreaders and bucket loaders;

(b) Cement batch plants, cement mixers other than transit mix, cement spreaders, carryalls, crawler cranes, crushers and crushing plants, diggers and ditchers, power units and plants;

(c) Earthmoving scrapers, electric generating equipment, electric load-bank and wiring equipment, front-end loaders, leveling graders, lighting plants and portable wiring, motor graders, payloaders, power hoists, road graders, scoopmobiles, skip hoists, stackers and hoists;

(d) Athey wheels, backhoes, bituminous and cement pavement finishers, drag lines, fork lift trucks, log loaders, mixmobiles, portable bins, portable parts and storage bins, portable shops, portable storage tanks, power shovels, road rollers, sheepsfoot rollers and paving mixers, towermobiles, welders, yarders;

(e) Bituminous and cement finishing machines, elevator equipment, scarifiers and rooters, traction engines, vibro screens and rotary screens, wheeled and crawler tractors other than truck tractors; and

(f) Apron feeders, grain grinders, grain rollers, sand classifiers and drags, sawmills and special construction equipment, scrap metal balers, scrubber screens and plate feeders.