As a special road structure, dual-branch on-ramp has more complex operating characteristics than other ramps due to different origin of vehicles. In order to improve operation efficiency on main line and guarantee the fairness of ramp vehicles, this paper proposed a coordinated dual-branch on-ramp metering control algorithm which considered the waiting time of each lane on ramps as optimal condition to assure fairness. In the meantime, the performance of the proposed algorithm was compared with several conventional ramp metering strategies through the simulation experiment. The simulations are conducted based on the data collected from Dongbang interchange of G4221 expressway which is one of the busiest highways in Jiangsu, China. Then two performance indexes are obtained and analyzed. The results indicate that the coordinated control strategy has optimal improvement on the mainline and the whole system.

CICTP