A method of operating an adaptive cruise control (ACC) system of a host vehicle includes operating a sensor onboard the host vehicle to determine respective dynamic state variables of a leading vehicle forward of the host vehicle and of a plurality of third vehicles in the vicinity of the host vehicle, and using a swarm algorithm to process the dynamic state variables of the third vehicles to predict future movements thereof Acceleration/deceleration of the host is controlled by the ACC based upon the variables and the predicted future movements of the third vehicles. The third vehicles may be sub-divided into first and second and respective first and second swarm algorithms applied thereto and later combined to predict future movements of the third vehicles. Third vehicles located ahead of the leading vehicle may be detected using radar signals that are reflected off of the road surface beneath the leading vehicle.