Measuring City-Level Transit Accessibility Based on the Weight of Residential Land Area: A Case of Nanning City, China

A large body of research on transit accessibility emphasizes the importance of methods to simulating the real-world travel process. Few efforts have been made to conduct empirical research and comparative analysis of overall city-level transit accessibility. In addition, most of literatures utilize census tracts combined with the buffer method to estimate transit travel demand or available service areas, failing to take into account the reality that different land-uses have their own population. This research aims to develop an overall index of city-level transit accessibility based on the weight of residential land area. We integrated five types of destinations and the coverage of residential area within the transit stop service area to evaluate the overall structural problems of land use and public transportation in the process of urban development. Based on a case study on Nanning City, it was found that the weighted average travel distance is increased by 5.42 km, but the overall weighted travel time of the city is shortened by 7.65 min. In addition, an increase in coverage within the stop threshold and a decrease in the number of residential communities outside the threshold indicate that transit accessibility facilitates urban expansion. The empirical results show that the overall transit accessibility index can provide a reasonable measure criterion for the compact spatial structure and support urban strategic planning and address the problem of land use and public transport in the process of urban development.