Study on variable-message-based routing control on expressway networks

On the basis of dynamic user optimum traffic assignment, this paper presents the method of expressway network routing control and builds an optimal diversion ratio model of each diversion node based on VMS control sequence. In the model, the generation of the sequence is determined comprehensively by both current and historical optimal diversion ratio while the two-value property of VMS control and users´ reaction to VMS routing guidance are taken into account to increase the applicability and flexibility of the controlling process. It also gives an initial analysis of multi-branch nodes. Cases show the method presented in the paper can adjust the traffic distribution on expressways and make rational use of network resources.