Dynamic variable speed limit strategies based on traffic flow model for urban expressway

The urban expressway network is an important part of the urban transport system which carries huge traffic pressure. It is also the key to the efficiency of the urban transport system. In this paper, the mesoscopic traffic flow models are improved by integrated with variable speed limits strategy to simulate the dynamic of vehicles on urban expressway network. The models include static queuing model, the velocity model and the vehicle movement model. Moreover the corresponding variable speed limits values can be obtained by proposed simulation method which can aid traffic managers to develop a network traffic flow control strategy. In the end, the elevated expressway network of Jinan city is used as a simulation example. We investigated the performance of the transport system with averaged density, speed and flow on link. We also analyzed the dynamic of the traffic system on expressway network at different demand level. The simulation results show that the proposed models and method are feasible and effective. The variable speed limits strategy can successfully alleviate the traffic congestion in some extent. The operational efficiency of the transportation system is greatly improved.