Also found in: Dictionary, Thesaurus, Wikipedia.
a light signal on a motor vehicle, trolley car, or similar vehicle that warns the drivers behind that the vehicle is braking. One brake light is situated at each side of the motor vehicle and is usually integrated with the taillights; the two lights are connected by a switch with the brake system’s pneumatic or hydraulic circuit. When the brake pedal is pressed, the diaphragm of the brake switch bends under the pressure of compressed air or brake fluid and closes a pair of contacts, thus switching on the brake lights. Brake lights are equipped with red diffusing lenses. The light intensity in the direction of the optical axis should be not less than 40 international candles. Brake lights with dual intensity modes for daytime and night driving are also produced.