Coordinated Control of Urban Expressways and Connecting Intersection Based on Genetic Algorithm

In order to reduce the impact of on/off-ramp on the main road of urban expressway and increase ground traffic efficiency at the same time, this paper proposed a coordinated control strategy for on-ramp, off-ramp and connecting intersection. The coordination control problem is transformed into a multi-objective optimization problem, using genetic algorithm to solve the optimization problem. Taking the intersection of Laodong South Road and Gaoxin Road and the adjacent pair of on-ramp and off-ramp in the west section of Second Ring South Road in Xi'an as simulation scenario, the coordinated control strategy mentioned in the paper is simulated and verified in the VISSIM. The simulation results show that: 1) Compared with the actual signal timing at the intersection, the coordinated control strategy can reduce the intersection delay, east import vehicle queuing length and expressway main road vehicle delay by 26.8%, 16.4% and 34.7% at most, and improve the traffic capacity of the intersection 10.7%. 2) Compared with Webster timing method, the coordinated control strategy can reduce the intersection delay, east import vehicle queuing and vehicle delay of expressway main road by 16.0%, 10.1% and 38.3%, and increase the intersection capacity by 3.8%. The conclusion indicates that the optimized intersection signal timing and on-ramp signal timing can improve the traffic efficiency of urban expressways and intersections.