Potential Impacts of China 2030 High-Speed Rail Network on Ground Transportation Accessibility

China has proposed an ambitious high-speed rail (HSR) program by 2030 to connect all provincial capitals (excluding Lhasa) and large cities with more than half million people. Little attention has been paid to evaluate its potential impacts on ground transportation accessibility. To answer this question, we adopted a door-to-door approach to calculate two indicators: the weighted average travel time and daily accessibility. The results show that the HSR network follows the same spatial patterns of population size and regional development, thus preferentially serving eastern China. The two accessibility indicators suggest that the large-scale construction of HSR network by 2030 will substantially improve accessibility and alter the spatial disparities of accessibility. On average, accessibility of all cities will increase by 61.7%. Geographically, cities with higher accessibility are located in the quadrilateral area of ‘Wuhan-Zhengzhou-Jinan-Nanjing’ on the southeastern section of the ‘Hu Line.’ While the least accessible cities are distributed in peripheral areas. Although the HSR development can benefit accessibility throughout the country, the disparities of accessibility would widen slightly among regions, provinces and cities.