The Spatiotemporal Effects Of Rail Transit Network Considering Built Environment On Travel Characteristics ——A Case Study Of Wuhan

The increasing travel time has seriously affected the quality of life,and rail transit has become an important way to relieve the pressure of travel in big cities because of its high efficiency and convenience.Rail transit is a complex network with scale-free and small-world characteristics,and its network expansion process positively affects residents’ travel characteristics under spatial and temporal constraints by changing accessibility times and the built-up environment around stations.Existing studies are mostly based on cross-sectional data,lacking measures of the quality of the stations themselves,and are unable to explore the dynamic response patterns of rail transit networks and travel characteristics.This paper takes Wuhan as an example,constructs a topological network of rail transit over the years,measures the spatio-temporal evolution of its accessibility,and analyses the influence of the built environment around stations on travel characteristics through stepwise regression based on time-series panel data.The results of the study show that the rail transit network in Wuhan shows the characteristics of a scale-free complex network and has been transformed from a tree-like to a loop network.The opening of the line 3 has had a significant influence on the formation of a loop in the network,and with the increase of rail transit lines and the expansion of the rail transit service area,the travel efficiency of the rail transit network has been improved and the robustness of the network has increased.The accessibility pattern of the rail network shows a shift from corridor to network,and the degree of change in accessibility time shows a circle structure,with a decreasing spatial distribution trend from the central city to the periphery.The opening of the Line Yangluo,Line 11 and the Southern Extension of Line 2 on the periphery of the central city has largely increased the overall travel time of the network and reduced its accessibility.At the same time,the direction of relocation of the centre of gravity of the rail network accessibility echoes the direction of Wuhan’s urban spatial development.The rail network has a significant effect on the travel characteristics,with the average travel distance increasing and the average travel time becoming longer as the accessibility of the network decreases.The built environment around a station has a significant effect on travel characteristics.Whether a station is an originating station,an interchange station or a hub station has a significant positive effect on the average trip frequency of urban rail stations;the larger the floor area ratio,land use mix,number of nearby sub-centres,number of bus stops,food and beverage services and parkland,the higher the average trip frequency;the larger the number of medical facilities and institutional groups,the lower the average trip frequency.Site attributes are significantly correlated with average trip frequency,with interchange stations significantly more frequent than average stations,while origination and hub stations are less frequent than average stations;the greater the road length and proximity to sub-centres,the higher the average trip frequency;the greater the number of intersections,floor area ratio,proximity to main centres and food and beverage services,the lower the average trip frequency.Station attributes are significantly correlated with average travel distance,with originating stations and hubs significantly higher than average stations,while interchange stations have lower average travel distance than average stations;the greater the number of intersections,floor area ratio,proximity to main centres,proximity to secondary centres and the number of bus stops,the higher the average travel distance;the greater the population,road length and land use mix,the lower the average travel distance.This paper investigates the spatial and temporal evolution of the rail network and residents’ travel characteristics.By analysing the influence of accessibility and the built environment around stations on travel characteristics,it provides insight into the spatial organisation of the city and the distribution of transport demand,and proposes strategies for the construction and operation of the rail network from the perspective of the complex network and the built environment around stations,thus providing further support for rail transport optimisation.