Traffic Safety Management Of Chang-Ying Expressway Under Adverse Weather Conditions

In recent years， the mileage of expressway in Jilin province has grown rapidly，reaching4000kilometers as the time of this paper. The task of making sure thatexpressways run as safely and smoothly as possible is one of the most crucialmissions challenging any traffic administrative agencies. Jilin province is located in alow-temperature region with heavy snows， the expressways of which are oftensubject to influences from rain， snow， fog and other adverse weather conditions. Inorder to make sure the safe running of expressways， when adverse weather occurs，road and traffic administrative agencies often have to consider adjusting the speedlimit of the traffic， or even， shut down the entire road sometimes.At present， road and traffic administrative agencies when confronting adverseweather conditions，although they have considered multiple situations，and come upwith a great deal of countermeasures and preventative measures， fundamentally theystill rely on experiences， lacking proper and quantitative management methods thatare in line with scientific findings， too often the result of which is that speed limitsare improperly set and roads improperly close down.This paper focuses on the study of Chang-Ying（Changchun to Ying Chengzi）Expressway， investigating the standards of road closure and safety facilities underadverse weather conditions， after field-researching and analyzing its weather andtraffic flow features. According to the thickness of water film and the firmness of iceand snow， this paper establishes the quantitative relationship model between rain，snow， fog and the coefficient of friction，and according to vehicle skidding andoverturning threshold conditions，establishes a set of expressway standards of closurebased on road friction coefficient；According to the degree and force of rain and snow， as well as the thickness of fog， establishes their relationships with road visibility；According to the vehicle break model， establishes a road closure standard， and inturn results in a expressway speed-limiting model. And at last，from the basis ofanalyzing the characteristics of road traffic safety，this papers gives managementsuggestions to how Chang-Ying expressway should be managed under adverseweather conditions， from the perspectives of road-side warning and informationsigns， guardrails and guide lines.The results of this paper can be used as a reference of management to theChang-Yingexpressway administrative agency，as well as providing solutions andsuggestions to expressway administrative agencies elsewhere in high latitude，low-temperature regions.