Study On The Methods Of Urban Regional Traffic Variable Message Signs Setting Locations

With the increasingly prominent of traffic congestion and other transportation problems, Traffic Flow Guidance System has become one of the main instruments of the current urban traffic guidance, and variable message signs-VMS is the mainstream of outside guidance.This study mainly on urban regional traffic variable message signs setting methods. The full text is divided five chapters:Chapter 1: IntroductionThis chapter introduces the definition of Urban Traffic Flow Guidance System and analyzes urban traffic flow inside and outside guidance systems from the different spatial distribution of guidance message. And then, a comprehensive review and summary of the development history and research situation of VMS in domestic and foreign countries is made. Finally, the main research content and arrangement of the whole paper are illuminated.Chapter 2: The basic theory of variable message signs systemsFirst, The Urban Traffic Flow Guidance System is introduced from the whole facts. Through the introduction of the basic theory of variable message signs, the paper establishes the information flow of VMS guidance systems. The basic idea is: the systems accesses various traffic parameters from various traffic data acquisition interface, analyzes and processes the collecting data by using the mathematical models, and points out the various traffic incidents. After the traffic commanding officers make sure the incidents, the preferences programs are activated. When the preferences programs are activated, the systems generate guidance information and present the information by VMS. Otherwise, the preferences programs are not activated; it will carry out manual modification until the preferences programs are activated. On the basis of the analysis of the traffic flow distribution theory, the paper gives the definition of the guidance rate, as well as the influence factors. The guidance rate of many countries is introduced.Chapter 3: The setting indexes identified and information needed analysis of variable message signsVMS setting is inseparable from the user need. This paper through the analysis of different users shows that different users need different information. The setting influence factors are as shown: investment, land using distribution, network layout, rate of road accident, road grade and traffic flow state, and so on. The rate of road accidence of which is the primary factor. The principle of VMS setting and the selection of setting indexes are established. The paper analyzes the indexes selection of the existing setting methods based on the principles of the selection of setting indexes. Finally, VMS setting indexes based on genetic algorithm are put forward for the shortage of the existence methods.Chapter 4: Study on the methods of urban regional traffic variable message signs setting locationsIt first sums up the current situations of VMS setting methods and mainly includes the VMS setting methods based on grey decision-making and fuzzy decision-making. The problems of the indexes selection of the existing methods are analyzed. Based on these, this paper proposes VMS setting method based on genetic algorithm. The simulation network is established by the use of VISSIM traffic simulation software, and then corresponding data is output respectively according to the deployment of setting indexes of the above three methods. Finally, the paper analyzes and computes the data, and accesses the setting results. In order to reflect the superiority of the different setting methods, the paper makes qualitative analysis about the results according to the principles of VMS setting and the selection of setting indexes, and also makes quantitative analysis about the results by using the average journey time, the average delay time, the average parking time and the average queue length for the evaluation objects. From the above results, the paper found that VMS setting method based on genetic algorithm is superior to the setting methods based on grey decision-making and fuzzy decision-making in the system optimum principle.Chapter 5: Summarization and ExpectationThis chapter summarizes the main research achievements and some prospective advises of the further study are pointed out.