A collision avoidance system (CAS), also known as a pre-crash system, forward collision warning system, or collision mitigation system, is an automobile safety system designed to prevent or reduce the severity of a collision.[1] In its basic form, a forward collision warning system monitors a vehicle's speed, the speed of the vehicle in front of it, and the distance between the vehicles, so that it can provide a warning to the driver if the vehicles get too close, potentially helping to avoid a crash.[2] Various technologies and sensors that are used include radar (all-weather) and sometimes laser (LIDAR) and camera (employing image recognition) to detect an imminent crash.