Research On Safety Optimization Methods Of Arterial Highway In The Process Of Urban-rural Integration

With the development of urban and rural integration process,the original arterial highways gradually become the internal roads of the town.Both sides is filled with new uptowns,factories.Traffic becomes more complex with the increase of pedestrians and non-motor vehicles.Road condition is so serious that can not adapt to the rapid growth of travel demand and accidents occur also high.Therefore,it is necessary to carry out safety optimization technology research on the arterial roads.First,on the basis of the analysis of the accident characteristics and accident-prone sections of S335,this paper summarizes the security problems.In view of these problems,this paper puts forward the optimization designs:road access management techniques,main and auxiliary road optimization techniques,intersection channelization techniques and spatial line of 3D sight distance optimization techniques.Second,to solve the problem of too many crossings,this paper introduce the road access management techniques.It summarizes the principles and existing problems of road access and studies the key techniques.In the intersection access management,it proposes reasonable spacing of intersections,recommended value of corner clearances,median openings optimization way,merge function zone access road,and so on.In the general road access management,this paper puts forward recommended value of access distance,access road control and access sequence optimization.In addition,this paper proposes reasonable access length,width,slope and canalization of access point.Third,in view of the traffic mix of the rapid transit and slow area traffic,motor and non-motor vehicles,this paper proposed the optimization by using the ground integral main and side roads based on urban expressway.It analyzes the forms and adaptability of the main and side roads,then discusses the key techniques.It analyzes the shortcomings of the existing model of entrance accelerating lane and establishes the vehicle merging model and studies the lane utilization rate of the acceleration lane,merging speed,merging length and overlapping length,which verifies the accuracy and validity of the merging model.Based on the intervals of entrance and exit of the interchange ramps,this paper proposes the least intervals of four main forms of entrance and exit.A reasonable value of outlet width is proposed based on actual capacity analysis of the outlet.Then,for the traffic disorder of crossings,this paper takes intersection channelization into consideration.It summarizes the safety condition and characteristics of intersection channelization and studies the key technologies.It analyzes the existing problems and the channelization optimization scheme of right-of-way class and light control intersections.Considering the influence of overcrowding intersections on traffic,this paper puts forward the scheme of the speed limit and the minimum length of the speed limit area.Finally,considering the problem of the sight distance,the paper proposes 3D sight distance optimization and studies the key techniques.This paper establishes the calculation model of available parking sight distance SSDa and demand parking sight distance SSDr and the inspection processing of parking sight distance and corresponding measures.Then it calculates the lateral clear distance in variable design speeds to analyzes the sight distance of surpass lane outside medians and proposes measures Furthermore,it puts forward the reasonable distance and height of medians green.