Oregon Revised Statutes Chapter 815 § 815.160 — if the person so charged produces a variance permit issued under ORS

if the person so charged produces a variance permit issued under ORS 818.200 authorizing the operation issued prior to and valid at the time of the offense. (4) Vehicles actually engaged at the time in construction or repair of highways in this state. (5) Traction engines moved upon dirt or unimproved roads. (6) Vehicles equipped with chains as defined in ORS 815.045. (7) Between November 1 of any year and April 1 of the following year, vehicles equipped with any tire having on its periphery studs of metal or other material projecting beyond the tread surface of the tire not less than four-hundredths (0.04) inch nor more than six-hundredths (0.06) inch and made of such material that the studs will wear, through use, at the same rate as the tread surface of the tire. When the preservation of the highway surface or the safety of the traveling public so indicates, the Department of Transportation shall have the authority to shorten or lengthen the period for the permissible use of such tires in any area of the state specifically designated by the department. (8) School buses with a loaded weight of 10,000 pounds or more. (9) Emergency vehicles and ambulances used in an emergency situation. (10) Motor vehicles used for regularly scheduled medical transport services. (11) The owner or lessee of any land adjoining any highway may move across or along the highway any tractor or implement of husbandry for the purpose of planting, cultivating, caring for or harvesting any crop, on condition that the owner or lessee shall be liable to the State of Oregon for the benefit of the State Highway Fund with respect to state highways, or to the proper county for the benefit of the county road fund with respect to county highways, for any damage or injury done to the highway by the movement. (12) Vehicles equipped with retractable studded tires as defined in ORS 815.045. [1983 c.338 §479; 1985 c.420 §7; 1997 c.493 §4; 2003 c.757 §1; 2007 c.406 §2]