Study On Key Technology Of Traffic Guide System In Province Freeway Net

In recent ten years, freeway increased quickly in our country, freeway net is coming to true in every province. With the rapid development of society economy and the continuesly increasement of requirement in province range freeway net, it became an emergency task for freeway management department to set up traffic guide system. Freeway system operation is complex, so many management and technology problems are faced while seting up traffic guide system in province range.The study developed depending on the project of integrated surveillance system constructing for freeway net in Shaanxi province. Stand at the point of requirement in setting up factual traffic guide system, the paper systematically studied key technology problems faced in setting up traffic guide system in province range freeway net.At first, the paper systematically analysed user requirement in freeway net traffic guide system according to general way in constructing information system. Then the scene analysis method was adopted to confirm information requirement to drivers in every stage from time travel not begin to travel ended. Information was classed at the view angle of collecting information. Technology characteristics were compared and strategies under different scenes were made.On the basis of analysing present management mode, mainly framework archtecture technologies for network software were compared and analysed in multi-angles and Web Service was selected as the technology of data exchanging. Since software can be flexible employed and the guide system can adapt to all kinds of management mode. By analysing netware safe technologies, technology routine of transporting data from private net to Internet was confirmed:network switch method or work mode of combining single direction communication software with fireware configuration.Refer to the theory of image encoding, datas to describe traffic states were encoded to a simple encoded code, and the encoded code represents the evolvement of traffic states. So the traffic states can be forecasted by searching history evolvement mode. Dynamic shortest path in freeway net can be got on the basis of the forecasting method and the event result is also analyzed at the same time. Traffic guide information will be shown at crotch is auto-deduced to make watch publish traffic guide information rapidly and exactly in province range freeway net.Under to-saturation traffic state, single substitute routine can not support volume from jam routine, k substitute routines were needed to share this volume. By the method of balancing traffic load level, the paper assign volume from jam routine to k substitute routine to ensure the freeway net runs without large-scale vibrant block while a routine is jammed. In order to enhance the impact guide system put on the factual traffic, method of flexible closed-loop control is used to make traffic turns to expected state according to the system optimization principle.The study is used at the first stage of the project and algorithms are expected to be optimized while running. Therefore, several issues that should be continuesly perfected are summed up at the end of the paper.