Design of an adaptive fuzzy logic controller for traffic signals

An adaptive fuzzy logic signal controller (AFC) is presented for the urban traffic network. The AFC is composed of the signal control system-oriented control level and the signal controller-oriented fuzzy rules regulation level. The control level decides the signal timings in an intersection by a fuzzy logic controller. The regulation level optimizes the fuzzy rules by the adaptive module in AFC according to both the system performance index in current control period and the traffic flows in the last one. Consequently the system performances are improved. A weight coefficient controller (WCC) is developed to describe the interactions of traffic flow between the adjacent intersections. So the AFC combined with the WCC can be applied in a road network. Evaluation of the performance on a real traffic scenario has been conducted. Simulation results indicate that the adaptive controller for traffic control shows better performance than the actuated one.