Emergency vehicle lighting is generally used to clear the right of way for emergency vehicles, or to warn approaching motorists of potential hazards, such as a vehicle that is stopped or moving slower than the rate of traffic, or a car that has been pulled over.
The use of emergency beacons is restricted by law in many jurisdictions only for responding to an emergency, initiating a traffic stop, bona fide training exercises, or when a specific hazard exists in the road.