Design real-time traffic information by cell transmission model

The variable message signs (VMS) have been widely used in guiding and managing the dynamic traffic with development of intelligent transportation technologies. Such traffic dynamics as shock waves and jam can be well reproduced by cell transmission model (CTM). A new method to estimate the route travel times based on the CTM was presented and the LOGIT rule to govern the route choice was adopted. The impacts of VMS on recurrent and non-recurrent congestion were numerically investigated using the formulae proposed. The real-life traffic conditions could well be reproduced as simulation results shown. Travelers' decision making could be positively influenced by the VMS so as to alleviate the grave degree of recurrent congestion. In the case of non-recurrent congestion, the VMS induced similar effects no matter high and low the traffic demand was. However, the resultant flow pattern was sensitive within a small range of the model parameter when the demand was high.