A Decentralized Route Guidance Algorithm in Urban Transportation Networks

In the last decades, due to the increasing car traffic and the limited capacity of urban networks, algorithms for traffic management and route guidance are becoming more and more important. GPS technology can be used for fleet monitoring in urban or suburban areas, from a central monitoring station and may provide useful information concerning the movement of all vehicles. Current route guidance systems are simple from an algorithmic point of view (they compute shortest paths to the destination), but they have to deal with huge size networks. For this reason, a decentralized approach, in which each vehicle independently calculates its own route, is desirable. Naturally, to limit the congestion due the vehicles decisions, an estimate on the different possible routes is required. Hence, we propose a decentralized algorithm in which each vehicle computes its own route on the basis of the traffic information provided by the reference station. Moreover, we propose a method for forcing vehicles to choose different paths and for informing the reference station on the routes of all vehicles, so that traffic forecast is updated.