Location Measurement Of High-speed Rail Traffic In The Yangtze River Delta Based On Accessibility And Mobility

Since the 21st century,China’s high-speed rail construction has been in full swing,especially in the Yangtze River Delta.The construction of high-speed rail plays an important role in promoting the improvement of traffic accessibility,the flow of elements and the upgrading of urban industries.It changes the spatial connection between cities and reconstructs the hierarchical structure system and traffic location pattern of cities.The measurement of high-speed rail traffic location has certain practical significance for understanding the status and role of cities in regional high-speed rail network and providing practical development suggestions for urban development.Based on the Yangtze river delta cities as the research object,this paper conducts an empirical analysis of high-speed rail traffic location of cities in the Yangtze River Delta from the perspectives of traffic accessibility and "traffic flow" network structure by using the train schedule database and the Baidu Map navigation dataset,based on the literature on the theories and methods of traffic location measurement.Firstly,the travel time measurement model is constructed to measure high-speed rail traffic locations using accessibility indicators.Then,the "driving" model is introduced as a comparison to analyze high-speed rail traffic locations from the perspectives of the change of accessibility distribution pattern and value,intercity travel choice tendency,and space-time compression.Secondly,based on the data of high-speed rail train schedule,the "flow space" theory and social network analysis method are used to analyze the rank and status of high-speed rail cities in the network from the perspectives of network nodes and network connections.Thirdly,Clustering the evaluation of traffic location index and classifying the city type according to the characteristics of traffic location.Finally,combining with the future regional development of the Yangtze River Delta and the recent construction of high-speed rail,The development strategies and suggestions of cities with different traffic locations are discussed.The main conclusions are as follows:(1)The spatial distribution pattern of accessibility presents a "core-corridor" structure,forming high-value accessibility corridors along the Beijing-Shanghai high-speed rail and spreading unevenly to both sides.Compared with the "driving" mode,the traffic location of "high-speed rail" has a spatial restruction.It not only improves accessibility,but also widens the differences between cities,showing the "Matthew Effect" and strengthening the traffic location of high-grade cities.The medium and long-distance high-speed rail travel in some cities does not have market competitiveness.The "space-time compression" of high-speed rail is more obvious,and the location of high-speed rail traffic in different cities presents great differences.(2)High-grade cities in the high-speed rail network are mostly distributed along the national trunk railways such as Beijing-Shanghai High-speed Rail,Nanjing-Hangzhou-Ningbo-Taizhou-Wenzhou High-speed Rail and so on,which adapt to the economic strength of the cities and are mostly located in the intersection of railways.The Shanghai-Nanjing-Hangzhou Delta region forms the core with the closest regional connection.The high-intensity connection radiates to the northwest and southeast of the region with the core cities as the center.In the regional connection,fewer urban connection pairs cover more High-speed trains.The classification of condensed subgroups shows that the direct high-speed rail connection between cities in central and northern Jiangsu and cities in the western part of Yangtze River Delta is weak,while the high-speed rail cities along Beijing-Shanghai,Ningbo-Hangzhou-Ningbo-Taizhou-Wenzhou become the hub of transit connection.(3)Based on the identification of the central city and the urban organization structure,the spatial pattern of "one circle,four belts and multiple corridors" with Shanghai,Nanjing and Hangzhou as the core is formed in the region.High-speed rail traffic locations that integrate accessibility and mobility can be divided into four levels:regional high-speed rail hub regional high-speed rail secondary center/central hinterland,local high-speed rail center,and marginal high-speed rail city.