A more advanced version of Electronic Cruise Control, ACC maintains the speed set by the rider, but adjusts the vehicle speed to maintain a suitable following distance from the vehicle in front. A front-facing radar sensor uses millimetre-wave radar to scan ahead in the rider’s lane. The system takes into account the proximity of the vehicle ahead, degree of road slope, front/rear wheel speed, and the rider-selected distance setting (Near, Medium, or Far). When the distance to the vehicle in front is deemed insufficient, the system directs speed to be reduced. When the necessary decrease in speed is not great, this can be accomplished with engine braking; when stronger deceleration is required, the system also activates the brakes. Once more space becomes available, the system directs speed to be increased and the throttle is increased to return to the set speed.