Study On Traffic Function Of Urban Expressway And Entrance And Exit Node

With the increasing urgent traffic demand in various cities in China,the density of urban road networks is increasing,and the problems of transportation are becoming more and more prominent.As the main skeleton of urban road networks,the efficiency of expressways directly affects the efficiency of the entire city.Therefore,accelerating the rational and standardized construction of expressways is a development trend in the new era.According to the city’s functional requirements for expressways,expressways should provide a safe,convenient,fast,and efficient driving environment for cities.However,as the economy and traffic volume increase,the city’s expressways and construction speed can not always adapt to the needs of the new times,the problem of traffic safety in urban expressways has become increasingly serious.Under the background of urban road traffic network,this paper starts with the concept definition of urban express roads and entrance and exit traffic nodes,driving characteristics and traffic characteristics,and summarizes the traffic problems when the entrance and exit of the urban expressway with other roads linkup.In addition,this paper analyses the traffic function of urban traffic on the expressway and its entrance and exit nodes in the new era.At first,Based on factors such as functional orientation,driving speed,and entrance/exit spacing,The ideas and preliminary grading standards for different grades of urban expressway are proposed.And then analyses the traffic organizations base on the different urban expressway traffic functions under different facade forms;and then,by taking into account the differences between entrances and exits and traffic nodes,the entrances and exits of urban expressways and their traffic nodes are analyzed,the settings of entrance and exit nodes and their traffic characteristics are studied,and the methods for selecting the type of entrance and exit points of urban expressways are summarized.In addition,the distances between road-section entrances and exits are calculated,and the distance values between intersection entrances and exits are calculated using the length calculation model;Finally,base on traffic safety,macro,meso,and micro-traffic optimization methods and strategies are proposed.And the concrete optimization suggestions are put forward in the eastern section of the South Second Ring of Xi’an.At the end of this paper,the traffic simulation software VISSIM is used to verify the optimization strategy and scheme proposed in this paper is effective and feasible.The study of the dissertation provides a certain theoretical guidance and direction for the classification of urban express roads,and supplements and perfects the current relevant road design specifications and standards,providing new research ideas and methods for the optimization and reconstruction of urban expressways.