Washington Revised Code Title 46. Motor Vehicles § 46.37.670. Signal preemption devices--Prohibited--Exceptions

(a) A law enforcement agency and law enforcement personnel in the course of providing law enforcement services;

(b) A fire station or a firefighter in the course of providing fire prevention or fire extinguishing services;

(c) An emergency medical service or ambulance in the course of providing emergency medical transportation or ambulance services;

(d) An operator, passenger, or owner of an authorized emergency vehicle in the course of his or her emergency duties;

(e) A driver of an organ transport vehicle when a vehicle is transporting a time urgent organ as defined in RCW 68.64.010;

(f) Department of transportation, city, or county maintenance personnel while performing maintenance;

(g) Public transit personnel in the performance of their duties. However, public transit personnel operating a signal preemption device shall have second degree priority to law enforcement personnel, firefighters, emergency medical personnel, and other authorized emergency vehicle personnel, when simultaneously approaching the same traffic control signal;

(h) A mail or package delivery service or employee or agent of a mail or package delivery service in the course of shipping or delivering a signal preemption device;

(i) An employee or agent of a signal preemption device manufacturer or retailer in the course of his or her employment in providing, selling, manufacturing, or transporting a signal preemption device to an individual or agency described in this subsection.