Study On The Coordinated Development Of China’s High-Speed Railway And Conventional Railway Systems From The Perspective Of Spatial Linkage

The China’s high-speed railway(HSR)network has gradually expanded from coastal areas and large-size cities to inland areas and small-and medium-size cities,causing continuous and profound socioeconomic effects in a vast territory.With the features of high speed,safety,comfort and large capacity,HSR system quickly occupies a preponderant role in intercity passenger market,and significantly impacts the market share of other transport modes.Many scholars have studied the impact of HSR on intercity passenger market and passengers’ travel behaviors,and discussed the relationship(competition or cooperation)between HSR and other modes,such as intercity coach and air transport.However,few studies have involved the analysis and comparison of the relationship between HSR and conventional railway(CR)systems.Although China’s HSR system is squeezing the market share of CR system,the CR system still keeps a large market share due to the low ticket prices and construction costs.In some regions,CR still has broad prospects.In this context,it is of great significance to discuss the spatial pattern and evolution characteristics of high-speed train(HST)and conventional train(CT)networks,and identify the superiority space of HST and CT services.It contributes to promoting the coordinated development of HSR and CR systems,and realizing the unification of efficiency and equity in railway passenger system.Accordingly,this paper analyzes the spatial pattern and network structure of China’s HST and CT services,and investigate the relationship between the two modes from from the perspective of spatial linkage.The strategies for the cooperation of HSR and CR systems are also proposed based on the empirical research results.Firstly,based on train schedules,this paper constructs the China’s HST and CT networks in five stages,including the year of 2007,2010,2013,2016 and 2019.On this basis,the characteristics of HST and CT services,including spatial pattern,spatiotemporal evolution law and network structure are analyzed and compared.Then,the spatial overlaps of HST and CT services are investigated,and the dominant space of HST and CT services are also identified.Finally,based on the door-to-door intercity travel time,this paper analyzes the variations of railroad travel efficiency and transport equity pattern after HST service completely replacing CT service.According to the dominant space and operation modes of HSR and CR systems,the strategies to promote the cooperation of HSR and CR are proposed.The following is the main conclusions of this paper.(1)The spatial pattern and network structure of China’s HST and CT services are significantly different,which indicates that the relationship between HST and CT services tends to be complementarity.HST services are concentrated in the short-and mediumhaul city-pairs within 600 kilometers and are more inclined to connect with large cities,while CT services achieve higher market share in the medium-and long-haul city-pairs beyond 600 kilometers and are more inclined to connect with small-and medium-sized cities.The hierarchical structure of HST network is more conspicuous,and the strong points and links of HST network are concentrated in southern China,while the strong points and links of CT network are mainly concentrated in northern China.Meanwhile,the HST network is characterized by a hub-and-spoke structure centered on provincial capitals and presents a territorial pattern divided by provincial administrative boundary,while the CT network presents a loose network structure.In terms of community structure,HST network strengthens the horizontal bond between cities along the Yangtze River,while CT network strengthens the vertical bond between cities along the BeijingGuangdong Corridor.(2)The dominant space of China’s HST services are expanding,but the CT services are still competitive in some regions.The expansion of HST services is usually achieved through “embedded modes” or “predatory modes”.The city pairs dominated by a single HST service are concentrated in the east side of Hu Line,while the city pairs dominated by a single CT service mostly connect with marginal areas.Besides,the dominant regions of HST service are mostly located in the four edges(including Beijing-Shanghai Corridor,Shanghai-Guangdong Corridor,Sichuan-Guangdong Corridor and Beijing-Sichuan Corridor)and the horizontal backbones(including Shanghai-Sichuan Corridor and Shanghai-Yunnan Corridor)of the “diamond structure”.Conversely,the CT services are predominant in Beijing-Harbin Corridor,Beijing-Guangdong Corridor and LanzhouUrumqi Corridor.The HST frequency,urban centrality in HSR network,urban hierarchy and per capita GDP have a positive impact on the superiority of HST service,while the geographical distance,proportion of tertiary industry,population in urban district and resident’s income have a negative impact.(3)Some regions and cities may suffer “involuntary high-speed railway travel” after HST service replacing CT service.In terms of travel efficiency,China’s southeast coastal area and Southwest China achieve the most accessibility improvements after HST service replacing CT service,while the impacts of HST services on accessibility improvements are relatively limited in Central China,Northeast China and Northwest China.Besides,in terms of transport equity,the cities in the four edges of “diamond structure” receive positive equity effect after HST service replacing CT services,while cities in Central China,Northeast China and Northwest China may face serious problems with“involuntary high-speed railway travel”.The relative improvement of accessibility and city’s wage level affect the equity index of the city after HST service replacing CT services,while the travel distance and the dominance of HST service affect the equity index of the city pair.The probability of positive equity effect caused by train service upgrade is greatest within the travel distance range of 600 to 2000 kilometers.(4)The coordinated development of HSR and CR systems is conducive to achieve the unification of efficiency and equity of railroad passenger system.In China’s eastern coastal area and West China(east of Xining)where HST services are predominant,the HSR network should be further improved to strengthen the positive effects of HSR on travel efficiency and transport equity.Meanwhile,in Central China,Northeast China and Northwest China where cities suffer “involuntary high-speed railway travel”,a certain proportion of CT services should be kept during the upgrade of train service.On this basis,the HST and CT services need to be integrated in order to avoid the damage of excessive upgrade of train service to transport equity.In conclusion,this paper reveals the spatiotemporal evolution of China’s train services in HSR era,and identifies the superiority space of HSR and CR systems through the allocation and spatial effect of train services.The study contributes to understanding the relationship between China’s HSR and CR systems and provides some policy implications for railway passenger system in order to coordinate regional development.