Adaptive Cruise Control (ACC) is a tractor feature that allows a vehicle's cruise control system to adapt the vehicle's speed to the traffic environment. A radar system attached to the front of the vehicle is used to detect whether slower moving vehicles are in the ACC vehicle's path. If a slower moving vehicle is detected, the ACC system will slow the tractor down and control the clearance, or time gap, between the ACC vehicle and the forward vehicle. If the system detects that the forward tractor is no longer in the ACC tractor's path, the ACC system will accelerate the tractor back to its set cruise control speed. This operation allows the ACC tractor to autonomously slow down and speed up with traffic without intervention from the driver. The method by which the ACC tractor's speed is controlled is via engine throttle control and limited brake operation.