Research on Fuzzy On-ramp Metering and Simulation in Urban Expressway

As the uncertain characteristics of traffic flow in urban expressway, fuzzy control can be used as an effectual way to solve traffic problem. A fuzzy logic approach is proposed to adjust the number of vehicles entering a mainline of urban expressway via entrance ramp during rush traffic times. The fuzzy logic onramp controller of urban expressway is designed based on such traffic information as the speed downstream mainline at the on-ramp, time occupancy upstream mainline at the on-ramp, and on-ramp queue length at the Surface Street. Simulation research based on MATLAB toolbox is carried out and the results show that the fuzzy ramp metering controller has a better performance for the traffic flow of urban expressway and it can avoid traffic congestion.