Suburban Highway Entrances Spacing Optimization Research

Due to the continuous development of city construction and propulsion,contact on the outskirts of the city is becoming more and more close,suburban highway as the contact between the two channels,has played a major role.And in the process of the construction of urban road,the road on both sides of the gateways Settings impact on road traffic efficiency and safety level is particularly important.But because at present our country to the relative lack of suburban highway entrances and exits of the design specification,not can carry on the effective management of inward and outward set,to a certain extent,led to the construction of suburban highway entrances and exits,suburban highway traffic accident cases occurred frequently,causing great loss of life and property.But also for suburban highway traffic related department for analysis and research,and took various measures to control and improve,but the effect not beautiful,suburban highway safety and efficiency problem still quite serious.In this article,through analysis of inward and outward spacing influence on suburban highway traffic flow to run,in order to improve the traffic operation efficiency and safety of motor vehicles as the goal,inward and outward spacing model is established,to improve and control of suburban highway entrances and exits,provides the theory basis.First of all,combined with domestic and foreign scholars on the research of the inward and outward classification method,with inward and outward around the nature of the land as the breakthrough point,classifying suburban highway entrances and exits,through out the entrance to a suburban highway line motor vehicle running speed of field investigation,analyzed the influence of the entrances to the main line motor vehicle running speed,as inward and outward classification rating index,significant difference analysis,verified the feasibility of the method.Secondly,studied the suburban highway entrances and exits influence range,speed characteristics,traffic composition characteristics of motor vehicles.And analyzes the running characteristics of motor vehicle,finally to the entrance to the mainline traffic in all kinds of traffic parameters(speed,capacity,and the conflict,the number of accidents)the impact of a brief elaboration.Combination of inward and outward spacing of suburban highway traffic flowefficiency and the influence of motor vehicle safety,this paper respectively in order to ensure that suburban highway road traffic capacity,to ensure that the adjacent gateway vehicles is not affect each other,the main vehicle and the vehicle's safety line,from the number of reduce the conflict and ensure safe driving range perspective,with synthetic entrances and to the inward and outward spacing as the research object,established the mathematical model of the minimum distance it is concluded that the different types of inward and outward and main driving speed,the relationship between road service level.Finally combining with the actual project cases,this paper puts forward the corresponding gateway improvement strategy,before and after using VIS SIM software to improve the effect is analyzed,prove the feasibility of improvement strategies.