Research On The Internal And External Accessibility Of Urban Rail Transit Stations Based On Network Map Service

With the continuous advancement of our country’s urbanization process and rapid economic development,urban residents have an increasing demand for the convenience of transportation.Urban rail transit has become an important part of the transportation system of large and medium-sized cities by virtue of its advantages such as large passenger volume,safety and comfort,high speed,low pollution and low consumption.When residents choose rail transit as a means of travel,due to the restriction of station density and spatial distribution,they need to be connected by other modes of transportation,such as walking,cycling,and bus travel,so as to complete a complete travel activity.As the external gateway of the rail system,the urban rail transit station serves as a bridge between the inner and outer living spaces of the rail transit.Accessibility as a comprehensive indicator of rationality and transportation capability for evaluating traffic system spatial layout.Studying the accessibility of the urban rail transit station can improve the operation level of the urban rail transit system,passenger travel satisfaction and guidance The development of the site area is of great significance.This article summarizes the traditional concept of accessibility,combined with the characteristics of the rail transit system itself,and defines the accessibility of rail transit stations in two aspects: the external accessibility of the site refers to the residents’ access under the radiation range of the site.Convenience of the urban rail system;the accessibility of the station;the convenience of a station in the rail network to reach any station in the rail system.On this basis,on the one hand,starting from the travel behavior of rail transit passengers,the two-step mobile search model is improved by dividing the travel circle and introducing the station service level factor,and the external accessibility model of the rail station based on the multi-mode transportation network is established.On the other hand,starting from the orbit system itself,the time accessibility model and the topological accessibility model of the orbit station are constructed from the two levels of the time network and the topological network,and the weight of the two is determined according to the entropy weight method to establish the orbit The internal reachability model of the site.For the acquisition of travel time in the two models,the article proposes an acquisition method based on network map services,that is,through the open source map database of the network provider,call the walking,cycling,public transportation and other routing algorithms provided by the network map API.Port to get travel time.After analysis,this method can effectively avoid the traditional GIS spatial analysis technology-based road network data modeling of different levels,ignoring the impact of traffic system factors such as actual road network accessibility,road congestion,and travel mode,so that it can accurately monitor the station.Quantitative evaluation of accessibility-related indicators.Finally,taking the rail system of Xi’an in November 2020 as an example,the reachability of 91 stations on 4 lines in the city was calculated from the two aspects of the accessibility of the station and the outside of the station,and the accessibility of the above-mentioned proposed network-based map service station was verified.The method is practical,accurate and easy to operate.At the same time,according to the calculation results,the time and space analysis of the internal and external accessibility of the rail stations in Xi’an is carried out,and four optimization strategies based on improving accessibility are proposed.