Study On Clear Distance Of Interchange And Traffic Safety Mechanism Of Interchange Exit For Ring Expressway

With the acceleration of urbanization,in order to improve the traffic efficiency of urban road network and relieve the traffic pressure,many cities gradually build ring expressway.As the hub of the traffic flow transformation of the city’s radioactive highways,national roads,provincial roads and urban trunk roads on the ring expressway,the setting of interchanges has become increasingly dense.The traffic flow in the interchange area of the ring expressway is complicated and variable,with poor driving stability and frequent traffic safety accidents,which makes the interchange a bottleneck section for improving the safety level of the ring expressway.Therefore,systematic analysis of the mechanism of clear distance and exit traffic accident of interchange in the ring expressway has an important role in improving the traffic safety of this section.Based on the analysis of the characteristics of the ring expressway,the road alignment,traffic volume,operating speed and traffic accident data of the interchange area of the Hangzhou ring expressway were investigated and collected in detail,and the exit area of the expressway of the ring expressway was analyzed in detail morphological distribution,time distribution,weather distribution,cause distribution and other rules and safety characteristics;Based on the influence of the special road traffic environment on the driver’s psychophysiology,using the theory of lane change,the calculation model of the clear distance between the interchanges of the ring expressway under different lane number and design speed is established,based on the relevant data and field investigation data of Hangzhou ring expressway,the specific net distance value of interchange is calculated and put forward;The traffic safety mechanism between the design index of the main line,the layout of the off ramp,the interchange spacing and the clear distance,the number of lanes,the exit recognition sight distance,the traffic composition,the information of the exit direction and the accident rate of the interchange exit is discussed,and focuses on the regression analysis of the relationship between the traffic volume of the main line,the traffic volume of the diversion and the accident rate of the exit area,so as to provide decision support for the establishment of the accident prediction model of the exit area of the interchange;comparative analysis of commonly used traffic accident prediction technology,based on the theory of multiple linear regression and neural network,a combination model of accident prediction for interchange exit is established,which provides data support for reducing the accident rate of interchange exit area and improving the traffic safety of ring expressway.