Patent US 7,061,402

An emergency vehicle warning system comprising a transmitter unit positioned within an emergency vehicle, and a receiver unit positioned within a passenger vehicle, wherein upon receipt of a radio frequency activation signal from the transmitter unit, an electronic chime within the receiver unit emits an audible alert, and thereby warns the driver of the passenger vehicle of the approaching emergency vehicle. The receiver unit additionally displays the relative position of the emergency vehicle upon a display panel. The receiver unit is additionally activated by sound waves associated with the siren of the emergency vehicle. The warning system alerts the driver to the approaching emergency vehicle before hearing the siren of the emergency vehicle, and thereby provides enough time for the driver of the passenger vehicle to safely pull over to the side of the road in order to allow the emergency vehicle to pass.