Research On The Techniques Of Traffic Information Promulgating System Based On GIS

This dissertation is based on the project of key Theories and Simulation Technologies of Dynamic Traffic Management and Control in Urban RoadNetwork, funded by National Natural Science of China under grant 50338030. With the development of the social productive forces, traffic becomes more and more important in the society life. And the demand of the traffic information has been increasingly on the upsurge. Traffic information not only can improve the actuality of the traffic congestion, but also reduce traffic accidents. Based on the retrospect of history and the current research on the traffic information system, this dissertation applies the Geographical Information System (GIS) to the traffic information promulgating, researches and developes the traffic information promulgating system based on GIS. Such system can use the geographic space information adequately to promulgate traffic information of the city which is more visualization, understandability and full-scale, and supply the effective implement for the analysis and inquiry.The system must choose an appropriate developing method, so this paper is based on the idea of the software engineering to choose the structuring lifecycle and prototype conjoint mode to design, and shows the development flow chat. According to the step of the development flow chat, this dissertation includes the master design of the system, the important function module design and the integration of the prototype experiment system. In the master design, the demand of the system is analyzed firstly, the systemic users and the requirements of the users.are confirmed. Systemic users are mainly classified as three categories, travelers, departments of traffic manager and road construction, departments of the traffic research. In this dissertation, with the example of travelers'requirement questionnaire on the Changchun city, the requirement of the drivers is particularly analyze. Next, based on the analysis of the system's requirement, the basic functions, logistic framework and systematical framework of the system are determined. The system consists of the collecting module, the communications module, the traffic information analysis module and the traffic information display module, which data stream is organized through standard interface to transmit and share information in each module. Finally, the secondary developing method is integrated in the system, and the software special for GIS (e.g MapInfo and MapX) and visualized development tools (e.g Visual Basic) are adopted as developing platform.In the couse of the development and the research of the system, separately the database module and the traffic information display module are investigated and designed in the dissertation, the main technologies of the designation and realization of system database, the line reference system method and the dynamic segmentation technology are also analyased. In the design of the system database, online-based disposal data model is established to manage and express the Multi-dimensional traffic information, with the effectively utilizing the traffic information relationship. For showing the information of the lane on the road availably, the system also establishes lane-based road data model. Realization and establishment of database is the foundation that supports systematic normal operation, which influences the efficiency of system analyzing and displaying information. According to the content of the traffic information promulgating, the data separating management has been put forward, with the data binding and ODBC connecting between spatial data and non-spatial data.This system achieves the dynamic connection, which handily inquires and displays information. The dynamic display is the key of the system. And the linear reference and dynamic segmentation can realize the function of search and show based on linear analysis, which was used to the location and dynamic display of traffic information on the road. So the results of the analysis information are more vividly promulgate. Dynamic segmentation data structure in Arc/Info are analysed and data structure to implement the dynamic segmentation in MapInfo are rebuilded. With the location of traffic accidents and the dynamic displaying of the traffic congestion, the dynamic technology is explained, and the flow charts are gived.After establishing database and confirming the critical techniques, author develops the prototype experiment system, and the process of designation is explained.Realization function module with many pictures of manipulation and result demo are proposed finally.Finally the main contents of the dissertation are reviewed, and then the innovation and the existing problems are pointed out. The research works which author needs continue study are also put forward.