Critical Path Signal Control Method for Eliminating Traffic Overflow

At present, the characteristics of high-intensity travel in China’s cities are becoming increasingly apparent. Influenced by the urban layout and road conditions of the high-density narrow road network, many short bottleneck sections have emerged, which are prone to long queues of vehicles overflowing during peak traffic periods, taking up space at upstream junctions and traffic congestion. Traffic overflow is highly contagious. If the traffic congestion is not dispersed or cleared locally in a timely manner, it can spread rapidly along the upstream junctions though the topological connections between the road sections and junctions, which in turn can have a cascading effect with serious consequences. In this paper, a phase difference calculation model to prevent green light idling and traffic overflow is proposed for roads with mild overflow, and a critical path signal optimization method is formed. The feasibility and effectiveness of the signal optimization method is verified through overflow simulation experiments conducted by microscopic traffic simulation software on the case of Zhongshan East Road in central Nanjing. This paper can provide theoretical support for the evacuation of light traffic overflows.