US Patent 9376051 First responders' roadway priority system

A method for notifying a first driver of a first vehicle that a first responder is ahead of the first driver on a road and that the first responder is stopped on the road. The method employs an optical emitter and optical detector apparatus. The optical emitter may be in or on a police car and may be turned on when the police car is on the shoulder of a road, such as when an officer has pulled a motorist over. The optical detector apparatus is in or on a vehicle traveling toward the police car that is stopped on the shoulder of the road. The optical detector apparatus communicates with a warning device to sound or display a warning to the driver of the approaching vehicle.