Simulation analysis for guidance benefit of travel time displayed by variable message signs

Travel time displayed by variable message signs (VMS) is an effective way to release freeway congestion. This paper investigates the relationship between guidance benefit of travel time displayed by VMS and update cycle. The investigation adopts macroscopic dynamic traffic network modeling method to combine travel time calculation model representing actual traffic control feature and route guidance model based on discrete choice models with macroscopic traffic simulation model, chooses travel time spend as guidance benefit evaluation index to analyze the relationship between guidance benefits and update cycles. Taking a network with two origins and two destinations as an example, simulation results show that travel time displayed by VMS can release congestion caused by incident significantly, and guidance benefits are inversely proportion to update cycles, and appropriate update cycle is not over 160 second. This study is effective for designing and evaluating traffic control strategies, and providing a basis for decision-making and references to relevant departments to improve the operational efficiency of the road networks.