Distributed Constraint Satisfaction for Urban Traffic Signal Control

Urban traffic problems including traffic accidents and traffic congestion or jams have been very serious for us. Urban traffic flow simulation has been important for making new control strategies that can reduce traffic jams. In this paper, we propose a method that can dynamically control traffic signals by equivalently representing as the constraint satisfaction problem, CSP. To solve local congestion in each intersection, we define the whole system as multi-agent systems where the represented CSP is extended to distributed CSP, DCSP, in each of which variable is distributed to each intersection agent. Each intersection agent determines some signal parameters by solving the DCSP. The proposed method is implemented on our separately developed agent-oriented urban traffic simulator and applied to some roadnetworks, whose experimental simulations demonstrated that our method can effectively reduce traffic jams even in the roadnetworks where traffic jams are liable to occur.