Research On Key Problems Of Urban Traffic Guidance System And Its Variable Message Signs

With the development of the national economy, the number of vehicles keeps increasing. However, the construction of urban roads failed to keep up with the development of vehicles, so problems such as traffic jam, environmental pollution, energy shortage etc. have become global difficulties. Under such circumstance, the application of intelligent transportation systems has drawn attention globally. Urban traffic flow guidance system, which is a vital part of the intelligent transportation systems is able to greatly improve communication efficiency for urban roads, and the Variable Message Signs (VMS) is an important tool in VMS to materialize public information service.Currently, VMS is installed in the trunk road networks in China's main cities, and played a positive role is easing traffic jams. However, the decision of where to rightly install VMS on the trunk road networks was made on subjective judgment, rather than on rational, theoretic guidance. Thus the question of how to find the right position to install VMS so as to give full play to its guidance effect needs to be answered. This thesis has put forward two evaluation models for the selection of VMS installation position, so as to make rational and right decisions on the selection of VMS installation position, according to different evaluation goals. Later, a simplified road network was chosen as the object of study, and the right installation position of VMS on it was figured out through greedy allocation arithmetic and road network simulation.At last, considering the fact that the basic information proceeding of urban traffic flow guidance system remains immature, and the system construction of urban traffic flow guidance system is imperfect, this study proposed new designs in these aspects, analyzed data procedures of urban traffic flow guidance system such as information collection, handling and output, and based on which, designed its system models.