Wash. Rev. Code § 46.32.060
It shall be unlawful for any person to operate or move, or for any owner to cause or permit to be operated or moved upon any public highway, any vehicle or combination of vehicles, which is not at all times equipped in the manner required by this title, or the equipment of which is not in a proper condition and adjustment as required by this title or rules adopted by the chief of the Washington state patrol.
Any vehicle operating upon the public highways of this state and at any time found to be defective in equipment in such a manner that it may be considered unsafe shall be an unlawful vehicle and may be prevented from further operation until such equipment defect is corrected and any peace officer is empowered to impound such vehicle until the same has been placed in a condition satisfactory to vehicle inspection. The necessary cost of impounding any such unlawful vehicle and any cost for the storage and keeping thereof shall be paid by the owner thereof. The impounding of any such vehicle shall be in addition to any penalties for such unlawful operation.
The provisions of this section shall not be construed to prevent the operation of any such defective vehicle to a place for correction of equipment defect in the manner directed by any peace officer or representative of the state patrol.
RCW 46.32.060
Construction-Application of rules-Severability-1987 c 330: See notes following RCW 28B.12.050.
Moving unsafe or noncomplying vehicle: RCW 46.37.010.