Study On The Disaster Condition Of Freeway Traffic Safety Management Technology

Traffic accidents on the highway happened frequently in recent years, especially theaccidents caused by unfavorable factors such as disaster weather and traffic incidents, whichhave a serious impact on the safety and the efficiency of vehicles on highway. With existingdisaster conditions, traffic management in our country focuses on the formulatation andimplementation of emergency management plan, mainly using administrative methods, whichresult in less shtrongly in pertinence and the purpose is not clear. Therefore, in order to ensurethe highway traffic safety and improve the operational efficiency of traffic under disasterconditions, it’s necessary to study on the key technologies about the traffic dredge and controlunder disaster conditions.Firstly, based on the characteristics of highway under the different conditions of fog,rain, snow and high winds, this paper studies on the limits of speed and distance. Consideringthe impact factors such as vehicle stability, water film thickness, and curve segments, correctthe road friction coefficient and driving line-of-sight in the speed limits model based onstopping sight distance. According to the principle of vehicle dynamics, get the speed limitsvalue under special circumstances (such as snow, ice) by using Adams/Car software. In thestudies of limited distance, according to different weathers and road traffic conditions, thispaper corrected the parameters such as the reaction time on the back of the car, the roadfriction coefficient and the minimum parking spacing.Secondly, according to the characteristics of the impact of traffic incidents, defined theguidance and control measures，which include speed limits, distance limits, guidance andtraffic flow limits. In the speed limits study, according to the ergonomic principles, using amethod based on the driver’s information processing ability, quantified factors of affectingspeed limits such as the road geometry information, traffic running information, traffic controland management information, climate and environment information, driver information, sothe best limited speed was obtained. In the distance limits study, the method of distance limitsunder disaster weather condition can be followed. In the traffic guidance study, according tothe real-time traffic volume of the main line of the disaster sections, using transformed smokeplume model to calculate the affected area of the upstream traffic flow, and then calculate thetravel time of both the disasters sections and shunt paths, then compare them so therecommended shunt paths were defined. In the`traffic flow limits study, using linearprogramming model to establish the objective function and linear constraints, and to amendthe highway capacity, the limiting values of each ramp could be calculated in time according to distribution law of vehicle arrival and the required security clearance of vehicle confluencein the mainline.Thirdly, according to the impacts of various disasters and their combinations to highway,the traffic safety management plan library of expressway was proposed in the paper, and therelated software including system management, road basic information, control and guidancesystem was developed. According to the real-time traffic information and disaster situations,this software can invoke the appropriate traffic organization plan and realize the control andguidance of freeway.Besides, each chapter combines the actual situation of Cangzhou coastal freeway withrelated theory proposed in this paper, the empirical studies of traffic safety managementstrategies under disaster conditions were realized.