The Study Of Traffic Safety And Monitoring System For Expressway In Fog Area

Along with fast development of the expressway construction and the growth of the automobile amount, the rate of accidents occurring on expressway has also increased. The accidents caused by fog along on the expressways have already received great attention from Chinese ministry of communications and press circles. The accidents caused by fog on expressway not only lessen the capacity of traffic passage, but also cause lots of injuries and deaths, bring large economic loss.The paper summarizes the researches on traffic safety and contral-technology in fog area from domestic and abroad currently. According to the definition of ambient fog and its physical characteristics, the conditions and features of the fog, of which is formed in the areas along some typical expressway, are pointed out based on analysis of heavy fog. In this work the regulation of geographic distribution and temporal distribution was introduced. With the Lambert-Beer law and the relative luminance contrast equation, the process of visibility reduction and traffic safety influenced by fog is analyzed. The paper discusses the change of visual range influenced by the microscopic parameters of fog. With the statistical method, relations between the visual range in fog and these parameters, such as number density of fog droplet and moisture content in fog, are analyzed. As a result, the regression relations are obtained. Aimming at the current economic level, the four methods of eliminating fog on expressway are discussed. At the same time, the paper chooses two equipments and wishes to apply them to eliminate fog on expressway. The compositive safe driving velocity limited in fog area is obtained using the Analytic Hierarchy Process.The paper establishes an expressway monitoring system for fog area, which constitutes of collecting information, processing controlling, displaying information, emergency rescue system, guidance and eliminating system etc... It introduced the advanced technologies and equipments of every part. On the base of existing levels of the highway safety facilities and managements, this paper gives some sugestions such as traffic establishes traffic safety management strategyes from the safety drive methods and the traffic organizing ways. The paper makes suggestions for insuring the monitoring system put in practice and traffic safety management strategyes carry out. It can be used to effectively prevent from accident occurring on expressway fog area.