Automatic Braking Type: the automatic braking type use either a single or combination of sensors (radar, lidar, and camera) to allow the vehicle to keep pace with the car it is following, slow when closing in on the vehicle in front and accelerating again to the preset speed when traffic allows. Some systems also feature forward collision warning systems, which warn the driver if a vehicle in front—given the speed of both vehicles—gets too close (within the preset headway or braking distance).