Research On Accessibility Of Urban Rail Transit Based On SUE Passenger Flow Assignment

With the accelerated development of China's urban economy,the scale of cities has been continuously expanded,various facilities have been continuously improved,the urban population has proliferated,and the living standards of urban residents have gradually increased,people's travel needs for various purposes are also growing.In order to solve the contradiction between travel demand and supply and alleviate road pressure,urban rail transit is vigorously developed in major cities across the country.Urban rail transit has the advantages of large capacity,fast speed and low pollution.It is the backbone of the public transportation system in contemporary large and medium-sized cities.Accessibility is an important indicator of the rationalization of urban rail transit construction planning,which can effectively reflect the interrelationship between urban land use,rail transit system construction and residents' travel distribution.Therefore,scientific research on the accessibility of urban rail transit has important practical significance for the development of urban transportation system and the layout of urban construction planning.Firstly,based on the research of accessibility at home and abroad,this paper defines the concept of accessibility clearly,introduces the characteristics of accessibility and traditional accessibility evaluation methods,and analyses the limitations of various methods.In this paper,the meaning of accessibility is the degree of easiness of urban residents to reach their destination from the starting point by using urban rail transit system at a specific time under certain urban land use conditions.Secondly,this paper introduces the concept and principle of passenger flow allocation in urban rail transit,expounds the basic concepts involved in passenger flow allocation,puts forward the basic theory of passenger flow allocation,such as utility function,User Equilibrium model,Stochastic User Equilibrium model,and lists a variety of effective paths and shortest path solving algorithms.Then,this paper establishes an urban rail transit accessibility model based on SUE passenger flow distribution,and distributes the passenger flow demand between urban rail stations during peak hours,and obtains the traffic distribution on each effective path between any pair of stations.Based on the traditional space barrier model,this paper calculates the accessibility index between stations based on the traffic distribution of each route,and uses the generalized cost in the passenger flow distribution model as the accessibility index to establish a set of site,line,area and network accessibility indicators.Finally,this paper takes the Wuhan Rail Transit Network in February 2018 as an example to establish a rail transit network structure model.Through the screening and cleaning of AFC card data,we obtain the OD matrix of the passenger flow in Wuhan during the morning rush hour on February 1,2018.By using Matlab programming to realize the SUE passenger flow allocation model,the path selection probability of the Wuhan subway and the passenger flow section data of the whole network are obtained.On this basis,the accessibility index of the stations,lines,regions and the whole network of Wuhan Metro is calculated,and compared with the traditional accessibility indicators,the credibility and correctness of the accessibility evaluation model are proved.