(1) It is unlawful to operate a vehicle upon the public highways of this state unless it is completely equipped with pneumatic rubber tires except vehicles equipped with temporary-use spare tires that meet federal standards that are installed and used in accordance with the manufacturer’s instructions.

(2) No tire on a vehicle moved on a highway may have on its periphery any block, flange, cleat, or spike or any other protuberance of any material other than rubber which projects beyond the tread of the traction surface of the tire, except that it is permissible to use farm machinery equipped with pneumatic tires or solid rubber tracks having protuberances that will not injure the highway, and except also that it is permissible to use tire chains, alternative traction devices, or metal studs imbedded within the tire of reasonable proportions and of a type conforming to rules adopted by the state patrol, upon any vehicle when required for safety because of snow, ice, or other conditions tending to cause a vehicle to skid. It is unlawful to use metal studs imbedded within the tire between April 1st and November 1st, except that a vehicle may be equipped year-round with tires that have retractable studs if: (a) The studs retract pneumatically or mechanically to below the wear bar of the tire when not in use; and (b) the retractable studs are engaged only between November 1st and April 1st. Retractable studs may be made of metal or other material and are not subject to the lightweight stud weight requirements under RCW 46.04.272. The state department of transportation may, from time to time, determine additional periods in which the use of tires with metal studs imbedded therein is lawful.

(3) The state department of transportation and local authorities in their respective jurisdictions may issue special permits authorizing the operation upon a highway of traction engines or tractors having movable tracks with transverse corrugations upon the periphery of the movable tracks or farm tractors or other farm machinery, the operation of which upon a highway would otherwise be prohibited under this section.

(4) Tires with metal studs imbedded therein may be used between November 1st and April 1st upon school buses and fire department vehicles, any law or regulation to the contrary notwithstanding.

Construction—Application of rules—Severability—1987 c 330: See notes following RCW 28B.12.050.

Dangerous road conditions requiring special tires, chains, metal studs: RCW 47.36.250.

Motorcycles and motor-driven cycles—Additional requirements and limitations: RCW 46.37.539.