With the availability of anti-skid brakes on automobiles, it becomes feasible to consider automatic braking as a means of absorbing impending crash energy. In this paper we describe an automatic brake actuation system for use on vehicles having an existing braking system. The brake actuation is triggered by an elongate detector fastened to the vehicle which is controllably extendable from the vehicle to contact objects being approached by the vehicle when at predetermined distance therefrom. A compression sensor is included to sense contact between the elongate detector and the object. Provision is made to sense vehicle speed, vehicle-object closing speed, and detector position and to extend and retract the detector and actuate the vehicle braking system in response thereto. Because of practical limitations as to the extent an elongate detector may be extended from the vehicle, the brake actuation system is effective at lower speeds, under 15 miles per hour. It is an excellent solution for the 2.5 mph bumper controversy in the U.S., and facilitates side impact protection.