Oregon Revised Statutes Oregon Vehicle Code § 818.225

(1)(a) In addition to any fee for a single-trip nondivisible load permit, a person who is issued the permit or who operates a vehicle in a manner that requires the permit is liable for payment of a road use assessment fee of seven and one-tenths cents per equivalent single-axle load mile traveled. As used in this subsection, “equivalent single-axle load” means the relationship between actual or requested weight and an 18,000 pound single-axle load as determined by the American Association of State Highway and Transportation Officials Road Tests reported at the Proceedings Conference of 1962. The Department of Transportation may adopt rules to standardize the determination of equivalent single-axle load computation based on average highway conditions.

(b) If the road use assessment fee is not collected at the time of issuance of the permit, the department shall bill the permittee for the amount due. The account shall be considered delinquent if not paid within 60 days of billing.

(c) The miles of travel authorized by a single-trip nondivisible load permit shall be exempt from taxation under ORS chapter 825.