关键词: 高速铁路, 可达性, 公平性, 空间格局

Abstract:

In China, with the drastic development of Chinese high-speed rail (HSR), assessing the impacts of HSR projects on transportation accessibility has recently been a hot topic for planners and researchers. Nevertheless, so far there has been limited research on exploring the implications of HSR on transportation accessibility, especially from the economic cost perspective. This paper studied the pattern and characteristics of land transportation accessibility influenced by China's HSR and travel cost. With the support of GIS technology and massive spatial data, the study constructed spatial analysis models based on shortest path algorithm and network analysis to calculate the accessibility index and generalized travel cost (GTC) parameter, so as to compare the pattern of land transportation accessibility before and after the construction of high speed rail for the planning year 2020. Firstly four accessibility indicators namely location indicator, economic potential, daily accessibility indicator and isochrones were used to measure time accessibility spatial distribution. Secondly, cost accessibility was measured by GTC. The accessibility maps address both the possible benefits and their spatial distribution. At last, the coefficient of variation of the accessibility values and its change before and after the construction of HSR was measured to represent the transport equity. Also the paper estimated whether the disparities of land accessibility were increased after the implementation of HSR. The results showed that from travel time perspective, HSR has improved overall level of the national land time accessibility and efficiency of passenger transportation, optimized the land transport network, then it tightened the connection among different metropolitan areas, expanded the radiation scope of the central cities. In addition HSR contributed to enlarging their service market demarcation and broadened markets of main central cities along the lines in short time distances. Furthermore cities along the HSR lines and in remote regions benefit most from the construction. HSR line had significant effect on the medium- and long-distance travel toward passengers, while short-distance travel mainly influenced the area along the railway lines.However, HSR led to more polarized accessibility patterns which indicated that various regions obtain unbalanced accessibility gain from HSR and enlarged the traffic inequity between different regions.As far as the travel cost accessibility was concerned, different demographic groups benefited differently from the HSR. Obviously travel cost accessibility pattern of the high-income groups was similar to the time accessibility pattern. On the contrary, for medium- and low-income groups, the HSR will not dramatically change the spatial pattern of economic accessibility. Therefore from traffic supply perspective, HSR only provided the possibility for the realization of the time-space convergence, which could greatly enhance regional social economic ties and reconstruct regional spatial pattern, which could not be achieved without passengers travel behavior' response to the HSR.

Key words: high-speed rail, accessibility, equity, spatial pattern