Maine Revised Statutes Title 29-A. Motor Vehicles § 2057-A. Preemptive traffic light devices prohibited

A. “Lighted traffic control device” means a traffic control device conforming to the requirements of section 2057, subsection 1.

B. “Preemptive traffic light device” means a device, including a signal prioritization device or a signal preemption device, capable of altering or interrupting the normal cycle of a lighted traffic control device or equipment associated with the functionality of a lighted traffic control device.

C. “Signal preemption device” means a device that, when activated and when a vehicle equipped with such a device approaches an intersection controlled by a lighted traffic control device, causes:

D. “Signal prioritization device” means a device that, when activated and when a vehicle equipped with such a device approaches an intersection controlled by a lighted traffic control device, causes:

A. An authorized emergency vehicle equipped with a signal prioritization device or signal preemption device or both maintained by a municipality, county or state agency or an ambulance or emergency medical services vehicle as defined in section 2054, subsection 1;

B. Transit route buses equipped with signal prioritization devices engaged in the transportation of passengers and maintained by or contracted to a municipal, county or state agency;

C. A vehicle equipped with a signal prioritization device used by the Department of Transportation for the purpose of installing, maintaining or testing a lighted traffic control device; or

D. A vehicle equipped with a signal prioritization device owned or contracted by a municipality engaged in snow removal or sanding operations on a public way and authorized by the municipal officers or a vehicle equipped with a signal prioritization device owned or contracted by a county or state agency engaged in snow removal or sanding operations on a public way.