(1) It is unlawful for any person to operate upon the public highways of this state any vehicle having an overall length, with or without load, in excess of forty feet. This restriction does not apply to (a) a municipal transit vehicle, (b) auto stage, private carrier bus, school bus, travel trailer, or motor home with an overall length not to exceed forty-six feet, (c) an articulated auto stage with an overall length not to exceed sixty-one feet, excluding a bike rack up to four feet in length, or (d) an auto recycling carrier up to forty-two feet in length manufactured prior to 2005.
(2)(a) It is unlawful for any person to operate upon the public highways of this state any combination consisting of a tractor and semitrailer that has a semitrailer length in excess of fifty-three feet or a combination consisting of a tractor and two trailers in which the combined length of the trailers exceeds sixty-one feet, with or without load.
(b) The restriction under this subsection does not apply to two trailers or semitrailers with a total weight that does not exceed twenty-six thousand pounds and when the two trailers or semitrailers do not carry property but constitute inventory property of a manufacturer, distributor, or dealer of such trailers. The total combination under this subsection (2)(b) may not exceed eighty-two feet of overall length.
(3) It is unlawful for any person to operate on the highways of this state any combination consisting of a truck and trailer, or log truck and stinger-steered pole trailer, with an overall length, with or without load, in excess of seventy-five feet. "Stinger-steered," as used in this section, means the coupling device is located behind the tread of the tires of the last axle of the towing vehicle.
(4)(a) The length limitations under this section do not apply to vehicles transporting poles, pipe, machinery, or other objects of a structural nature that cannot be dismembered and operated by a public utility when required for emergency repair of public service facilities or properties, but in respect to night transportation every such vehicle and load thereon shall be equipped with a sufficient number of clearance lamps on both sides and marker lamps upon the extreme ends of any projecting load to clearly mark the dimensions of the load.
(b) Excluded from the calculation of length under this section are certain devices that provide added safety, energy conservation, or are otherwise necessary, and are not designed or used to carry cargo. The length-exclusive devices must be identified in rules adopted by the department of transportation under RCW 46.44.101