Highway Video Detector To Optimize The Layout Method And Application

Compared with other countries in the world, the number of Chinese traffic accidents not is the highest. However, China is one of the highest traffic accident mortality. Traffic accidents threaten the safety of human life and affect the sustainable development of society. The early-warning system of freeway dangerous section which is in mountain area is just brought forward in this background.Dynamic traffic information collection is the key part and fundamental part of early-warning system. The optimal location of traffic detectors is lack of theoretical guidance. Although a variety of fixed-type traffic information collection technology have matured, particularly the video image processing technology, the distribution of traffic detector to some extent affect the reliability of freeway traffic performance which is reflected by the traffic parameters collected from detectors. The solution of the optimal detector deployment is essential for the early warning system.This article focuses on the freeway, considers the performance of video detector, and analyzes the demands of dynamic traffic information collection. Based on summarizing the defect of detector distribution methods, the new model of detector distribution was proposed.Firstly, the method which is based on traffic flow wave theory was improved. Automobile dynamic property was utilized in the calculation of system's spread time. Also, the distance from vehicle accident location to the potion that the car which was nearest from vehicle accident in upstream of the accident site chased up the truck which was nearest from vehicle accident in downstream of the accident site.was calculated. If the velocity of traffic wave greater than zero, according to the velocity of traffic wave and the time of system spread time, the spread distance of traffic wave was calculated in T. Adding the two distances which was above mentioned is the space of traffic detector; If the velocity of traffic wave less than zero, the space of traffic detector just is the former.Secondly, in the light of point velocity which was collected by detector, the travel time was calculated between the adjacent detector, by the method of travel time estimating. In accordance with the deviation of predictive value and true value and the demands of early warning, the distribution of optimal traffic detector was obtained.The method discussed in this thesis was applied in KunShi freeway(K50-K52).The practice examples showed the feasibility and validity of this method.