The Study Of The Secondary Accident Fore-warning Of The Expressway Under Network Condition

The construction of exprssway is the sign of traffic moving towards modernization. Butit brings managers and users irreparable property damage and casualties, at the same time, itbrings people great economic and social benefits. In recent years, as Chinese economicdevelopment, people’s living standards is rising, and trip mode is becoming diversificationbased on the multilateral form of rapid developing road. So if the accidents occur on theexprssway which in the complex environment networks, they can easily be the serious trafficaccidents. The "second accident" leded by the serious traffic accidents has become a majorkiller to exprssway. The prevention of exprssway secondary accidents becomes the key to safeoperation of exprssway. In order to avoid secondary accidents, exprssway operating managersshould scientifically and rationally analyse the factors about secondary accidents under thenetwork environment, and take preventive measures for traffic disaster and secondaryexprssway accidents.This article according to the fore-warning thought of “marking alarms condition-seeking the alert source-analyzing alarm sign-forecasting the degree alarming”. Throughcollecting data and comparison analysis summary the current research status at home andabroad on the secondary fore-warning, first of all, article introduces the basic theory offore-warning system from three aspects of theoretical basis of secondary fore-warning,theoretical framework, as well as the building steps, then ayalyzes the first accidents’ impacton traffic against traffic flow parameters, and analyses the causes of accidents under normalconditions and accident conditions. Secondly, based on the principles of constructing theindicator system, the article constructs the secondary fore-warning indicator system, andcalculates the fore-warning indicators. Thirdly, this article analyses the indicator distributionform, sets five warning limited intervals of each indicators using normal distribution’s3σ theory,comparative analysis and expert surveys and other methods, and then gives the five outputvectors corresponding to each warning grade when using neural network method. Finally, thearticle selects BP neural network as the system evaluation method to secondary fore-warning,and establishes BP neural network model of the secondary fore-warning, and study the information publishing method and content, then gives management strategy for differentwarning grades and serious accidents.