Study On Rear-end Accident Of Expressway Tunnel Section

With the rapid development of social economy in China,the transportation industry has also developed vigorously,and the mileage of expressway construction and operation has been greatly improved.For expressways in mountainous areas,the proportion of tunnels is higher and higher due to the restrictions of topography,landform and geological conditions.Some expressway tunnels account for as muc h as 50%.Because of the special traffic characteristics of tunnels,tunnels become the frequent road sections of traffic accidents.The accident investigation results show that rear-end collision is the main form of tunnel traffic accidents,up to 65%.Ba sed on the Kunming-Shilin Expressway,this paper collects the traffic accident data and traffic monitoring video in 2016 and 2017,gets the speed data of the tunnel section,studies the speed law of the vehicle in the tunnel section,and puts forward targe ted measures for the tunnel section management and control,so as to reduce the problem of rear-end collision in the tunnel section.The main work and research results are as follows:1.Starting from the traffic accident of Kunming-Shilin Expressway tunnel,the traffic accident data are analyzed and sorted out by SPSS data processing software.It is concluded that rear-end accident is the main accident type of tunnel section.The spatio-temporal distribution of rear-end collision is analyzed,and the spatio-temporal distribution characteristics of rear-end collision are obtained.Based on the analysis of longitudinal and longitudinal traffic conflicts of expressway,the relationship between rear-end collision and vehicle speed is obtained.2.Vehicle speed data are collected through monitoring video of tunnel section of Kunming-Shilin Expressway.Vehicle speed data are collated according to 15% of vehicle speed,50% of vehicle speed,85% of vehicle speed,average speed,acceleration and standard deviation of speed at characteristic points,and the characteristics of tunnel section speed are analyzed.It is concluded that there is a serious speed difference between vehicles in tunnel section and the speed dispersion is too large.It is found that the main causes of tunnel speed problems are the late deceleration of small vehicles and the excessive deceleration of large vehicles.3.Based on the comprehensive analysis of the influence factors of speed from the four aspects of human,vehicle,road and enviro nment,the main influence factors of speed are obtained.Combining with the speed characteristics of tunnel sections,it is found that the most direct and effective way to solve the problem of tunnel speed is to improve the speed limit in tunnel traffic co ntrol measures.4.On the basis of the speed characteristics,the improvement measures are put forward for the tunnel speed limit mode: adopting reasonable speed limit value and variable speed limit mode,and the feasibility of improving speed limit measur es is verified by VISSIM traffic simulation.