A multimodal approach to assessing accessibility of a high-speed railway station

In China, accessibility has been profoundly improved by the large-scale construction and operation of high-speed rail (HSR), with far-reaching implications for population flows and socioeconomic development. As a novel attempt to compare the shortest travel times, accessible regions, service populations, and population potential of one- to four-hour isochrones under four scenarios in Tanggu Railway Station (i.e., base scenario, hypothetical scenario 1, hypothetical scenario 2, and actual scenario), this paper analyses three factors' influences on and contributions to accessibility change: the advent of HSR, conventional railway route adjustment, and road network improvement. The results indicate that station accessibility significantly improved from 2007 to 2012. HSR has not only brought a time-space contraction effect to the region from the station to the north-western area but also strengthened interactions among different regions. Due to the reduction of some conventional railway routes, the shortest travel times from the station to the north-eastern areas have slightly increased. Although this factor has some negative effects, it has not affected the ascending trend of enhanced accessibility. Road network improvement is identified as a key factor with balanced impacts on all four-hour isochrones. The results of this study generate supportive information for the planning and construction of HSR stations and networks and provide references for comprehensive transport policymaking.