(2) The municipal officers or a municipal official designated by the municipal officers, with the approval of the fire chief, may authorize an active member of a municipal or volunteer fire department to use a flashing red signal light not more than 5 inches in diameter on a vehicle. The light may be displayed but may be used only while the member is en route to or at the scene of a fire or other emergency. The light must be mounted as near as practicable above the registration plate on the front of the vehicle or on the dashboard. A light mounted on the dashboard must be shielded so that the emitted light does not interfere with the operator's vision.

(3) Members of an emergency medical service licensed by Maine Emergency Medical Services may display and use on a vehicle a flashing red signal light of the same proportion, in the same location and under the same conditions as those permitted municipal and volunteer firefighters, when authorized by the chief official of the emergency medical service.