Washington Revised Code Title 46. Motor Vehicles § 46.61.212. Emergency or work zones--Approaching--Penalty--Violation

(a) A stationary authorized emergency vehicle that is making use of audible and/or visual signals meeting the requirements of RCW 46.37.190;

(b) A tow truck that is making use of visual red lights meeting the requirements of RCW 46.37.196;

(c) Other vehicles providing roadside assistance that are making use of warning lights with three hundred sixty degree visibility;

(d) A police vehicle properly and lawfully displaying a flashing, blinking, or alternating emergency light or lights;  or

(e) A stationary or slow moving highway construction vehicle, highway maintenance vehicle, solid waste vehicle, or utility service vehicle making use of flashing lights that meet the requirements of RCW 46.37.300 or warning lights with three hundred sixty degree visibility.

(a) On a highway having four or more lanes, at least two of which are intended for traffic proceeding in the same direction as the approaching vehicle, proceed with caution and, if the opportunity exists, with due regard for safety and traffic conditions, yield the right-of-way by making a lane change or moving away from the lane or shoulder occupied by an emergency or work zone vehicle identified in subsection (1) of this section;

(b) On a highway having less than four lanes, proceed with caution, reduce the speed of the vehicle, and, if the opportunity exists, with due regard for safety and traffic conditions, and under the rules of this chapter, yield the right-of-way by passing to the left at a safe distance and simultaneously yield the right-of-way to all vehicles traveling in the proper direction upon the highway;  or

(c) If changing lanes or moving away would be unsafe, proceed with due caution and reduce the speed of the vehicle to at least ten miles per hour below the posted speed limit.