The Study On Expressway Network Information System Served For Operating Safety

China expressway is in a period of high-speed development. However, the growing expressway network does not improve the traffic efficiency, but bring serious traffic safety problems. Hence, establishing expressway information system and taking advantage of all kinds of establishment in order to improve safety and traffic efficiency, is the urgent research work in the current research fields.In the view of dynamic management, this paper focuses on the expressway network, and analyzes the demands of expressway network information system. Based on the current technology, deep research work is performed on the key issues of information system including information collection, information distribution and dynamic safety evaluation. A standard of expressway network information system serving for safety management is proposed.Firstly, based on the overall summarization and analysis of all kinds of effecting factors on expressway network operating safety, the information collection requests are proposed according to the demands of expressway safety management.Secondly, starting from the research of the rear end collision, a real-time expressway risk evaluation model is established according to the information collected from multi-source of detectors. At the same time, the factors of road, traffic and weather are also taken into account, so this model can evaluate the real-time traffic flow very well.Thirdly, this paper focuses on the main parts of the information collection like the selection and location of the traffic information collection equipment and the weather information collection equipment. A feasible engineering standard is presented using simulation method and qualitative research method, which make groundwork for the efficient data collection and safety management of expressway network. Simultaneously, the comparisons and analysis among the current incidents detecting technologies and arithmetic provide well reference for selecting proper incidents detection technologies. Moreover, the abnormities in data collection process are considered, and the principal curve method is introduced into data pretreatment, which provides a new method for the efficient utilization of the collected data.Fourthly, variable message sign (VMS) is studied as the main information distribution technology. A group of standards are proposed for the location, design, recognization, information distribution content, information distribution scope, and information distribution time of VMS, which will popularize the utilization of VMS especially the graphical VMS on expressway and serve for the expressway operating safety management.At last, it summarizes the research results of this work, and forms the Shanghai Local standard "the Standard of Expressway Operating Information System under Disaster Weather". Moreover, the standard is used in Hangzhou bay bridge. Traffic information collection technology and weather information collection technology are selected and located on Hangzhou Bay Bridge according to the standard. The VMS on bridge is also designed and arranged. Taking a section of bridge with fog for example, the demonstrations of information distribution process, distribution scope, distribution content and distribution method are given at the last.