Fuzzy Traffic Light Control Based on Phase Urgency

Due to dynamical traffic flow changes in urban areas, traffic congestion occurs on many intersections over a certain period of time. Today there are still many traffic light controllers with fixed signal programs used on signalized intersections, which causes aggravation of the overall state of traffic. To solve this problem, some solutions have been presented within the field of Intelligent Transport Systems. This paper presents an adaptive traffic light controller based on fuzzy logic used for improving the traffic flow on an isolated intersection. Three methods of adaptive traffic light control have been designed in order to determine the urgency of a particular phase for adaptation of phase duration, phase sequence and simultaneously phase duration and sequence. The proposed adaptive methods are compared to a fixed controller in three scenarios with different traffic demands to prove their effectiveness. For this purpose, a model of an isolated intersection in the microscopic simulator PTV VISSIM, and a fuzzy based traffic light control system in the MATLAB programming environment have been implemented.