On-ramp Metering on Beijing Urban Expressway

Traffic flow characteristics are analyzed based on the representative site data collected from Beijing urban expressway. On the basis of the characteristics, the local on-ramp metering rate is determined by the comprehensive control effects from two parameters adopting time occupancy and speed as control variable to realize feedback control. In order to validate the feasibility of the method, we make use of VISSIM to validate this method by video survey data between Sitong Bridge and Lianxiang Bridge in North Ring. The simulation result shows that the method can improve average speed on mainline upstream at on-ramp about 7% and decreases the travel time on mainline section by 9.5% compared with un-signal control mode. It denotes that the method is feasible and can offer reference for the theory of ramp control and application in engineering practices.