Study On Variable Message Signs Location Method Based On Network

With the increasing of the private car ownership, the city traffic problem becomes more and more serious. Rational and effective induction ease the traffic pressure on road users to a certain degree. At present, the variable message sign (VMS) is the main inducing facilities. Now, many cities in China have installed VMS and ease the traffic problems to a certain extent, but there is lack of theoretical support for the choice of the VMS layout position, so how to choose the right location to lay VMS in the road network becomes a very worthy of study.This paper study on the VMS location problem. Firstly, the paper describes the basic theoretical knowledge of the VMS, and analyzes the layout requirements of the VMS and previous lessons learned in the layout of VMS, and describes the situation of the domestic and foreign scholars in the VMS location problem, and gives a detailed description of the currently existing three VMS location models and its respective analysis.Secondly, this paper proposes to use cross-classification to select VMS layout position. Cross-classification method first selects the sections’layout indicators to analyze, and hierarchy, and then after division, crosses each other. According to the classification after the cross-situation, determines the layout hierarchies. Under the qualified set number, in accordance with the layout level and layout order to determine the layout scheme. Lastly, selecting a Beijing’s simulation network to simulate and verify, obtains the layout scheme.Then, this paper puts forward to use comprehensive evaluation method to select the VMS layout position.Comprehensive evaluation method first makes sure the evaluation index system, the next, using gray decision-making and fuzzy decision-making to determine the VMS layout program, and also, eventually selects a Beijing’s simulated network to simulate and verify, and finally gets the layout scheme.Finally, according to the effectiveness of VMS laid on the sections to the road network to build mathematical optimization model, and using the branch and bound method to solve this model. In this model, the defined effectiveness of VMS to the road network consists of two parts, the information amount of VMS and the influence degree of VMS to the road network, and selects the same simulation network to simulate and verify, obtains the layout scheme.