Study On The Risk Evolution State Of Expressway Rear-end Accident Chain And Blocking Scheme

As a high grade highway,expressway has the characteristics of high speed,safety and high capacity.In recent years,with the continuous development of expressways,the traveling needs of the people have been met.However,while the expressways promote the economic development,the rapid growth of the mileage brings some safety risks.Rear-end collision is one of the most common traffic accidents on highways.Highway rear-end collision process can be simply summarized as in highway traffic environment,the car is driven with two car after car collided with the back end.Relevant studies show that the occurrence of rear-end collision accident will not only affect the smooth passage of the expressway but also lead to serious consequences of the accident,which poses a great threat to the personal safety of travelers.Therefore,it is particularly important to the study of highway accident,in the study of highway accident,most will focus on the past highway accident frequency,the number of casualties and property losses to forecast analysis for the corresponding parameters of the future years,but in fact,crash as the emphasis and difficulty in traffic safety,in addition to the severe impact of the crash to learn highway outside more specific process should pay attention to lead to crash.Based on this,in this paper the influence factors of Highway crash process Chain of events(i.e.Highway accident Chain,CHRI(Chain of Highway Rear-end Incident))as the research object,by CHRI driving evolutionary status as a research focus,build CHRI model,the risk of driving evolution for dangerous driving crash Chain block scheme is put forward,according to the simulation results verify the accuracy of the models.(1)According to the theoretical basis of accident chain and the influencing factors of expressway rear-end accident,the expressway rear-end accident chain(CHRI)is defined,and based on the definition of CHRI,the expressway rear-end accident chain conforms to markov process,which lays a foundation for the evolution model of the following paper.(2)In the process of constructing the driving risk evolution model,by analyzing the vehicle rear-end running process and kinematic risk evaluation parameters,the three parameters of rear-end collision time(TTC),workshop time(THW)and final workshop distance(PICUD)are selected and fuzzy logic is used to construct the microscopic driving risk state mathematical model.Furthermore,the Ordered Probit Model is constructed based on the data of expressway rear-end collision accident.Then the final mathematical model of driving risk state is constructed by combining the two.Finally,the general markov chain prediction model and the grey weighted markov chain SCGM(1,1)c prediction model are used to predict the driving risk state,so as to obtain the driving risk state evolution model of the expressway rear-end accident chain CHRI.(3)By proposing the basic idea of the chain blocking scheme for rear-end accidents and the efficiency evaluation indexes such as the safety and effectiveness of the blocking scheme,the simulation experiment was designed by using Pre Scan and MATLAB/Simulink to verify the accuracy of the driving risk evolution model and the safety and effectiveness of the blocking scheme.The experimental results show that the accuracy of the grey weighted markov evolution model is as high as 95%,about 5%higher than that of markov prediction results.With the blocking system,the reduction rate of driving risk level is roughly 10-50%,which can achieve the goal of reducing 3 risk levels on average,and the success rate of blocking scheme implementation can reach about 66%.Therefore,the research model of chain risk evolution and blocking system of expressway rear-end accident further enriches the theoretical research of expressway rearend accident,and has certain practical significance in expressway risk identification and safety promotion.