An Adaptive Route-Guidance Algorithm for Intelligent Vehicle Highway Systems

This paper describes an algorithm used for the navigation of a vehicle in intelligent vehicle highway systems (IVHS). An internal map is constructed in the computer main memory to reflect a relevant road network which can be updated by the Traffic Management Center (TMC) or other resources on line. The network information is simply decomposed hierarchically into the map by nodes alone to avoid exhausting memory capacity, to limit time-consuming searching, and to meet the real-time constraints for on-line planning. The algorithm adaptively switches from heuristic search to real-time heuristic search to find a near-optimal route from a starting location to a final destination for the vehicle, provided that one exists. Furthermore, this algorithm can resume the planning process on line whenever the road-network database is updated by real-time traffic information from TMC and filtered into the internal map.