Traffic signal control using fuzzy logic and MOGA

This paper presents a fuzzy logic adaptive traffic signal controller for an isolated four-approaches intersection with through and lest-turning movements. The controller has the ability to make adjustments to signal timing in response to observed changes. The "urgency degree" term, which can describe the different user's demand for green time is used in fuzzy logic decision-making in our algorithm. Using three levels model of fuzzy controller, we can determine whether to extend or terminate the current signal phase and select the sequences of phases. This paper describes a flexible form of fuzzy logic signal control whose performance can be tuned off-line using a set of parameters which define the fuzzy set membership functions for the input variables. Our work also demonstrates the feasibility of using a multiobjective genetic algorithm (MOGA) to find a set of optimal parameters for a fuzzy controller with a range of possibly conflicting performance measures. Simulation results show that our proposed controller produces lower vehicle delays and percentage of stopped vehicles than the traffic-actuated controller.