On-Ramp Fuzzy Metering and Simulation in Urban Expressway

In view of the high complexity and uncertain characteristics of traffic flow in urban expressway, 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. Taking account of the combine influence of traffic state on mainline and the on-ramp queue at Surface Street, the on-ramp fuzzy controller of urban expressway is designed based on such traffic information as the speed downstream mainline, time occupancy upstream mainline, 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 controller is feasible and reasonable to confirm the number of vehicles entering the mainline of urban expressway.