Incorporating Facility Diversity into Measuring Accessibility to Transit: A Case Study in Beijing

Transit as an alternative means of travel allows travelers to access a wide range of activities and services. In addition to focusing on how many job opportunities and other basic urban services such as parks and healthcare can be accessed by transit, more attention should be paid to how many transit services can be obtained and how easy it is to access them. It should be noted that accessibility by transit and accessibility to transit are not the same thing, and most existing studies tend to focus on the former while ignoring the measurement of the latter. However, accessibility to transit is an important concept that can provide a framework for understanding and explaining the availability of transit services. In the literature, transit is more often used as a tool for accessing activities and opportunities to analyze the basic services such as healthcare resources and job opportunities that can be accessed, which not only ignores the transit service provided by the means of transit as a supplying facility, but also ignores the diversity of facilities in the integrated public transportation system. With this in mind, this paper introduces the entropy index into the adjusted Gaussian two-step floating catchment area (2SFCA) method to measure accessibility to transit to capture how the overall accessibility changes when considering different transit facilities. From the spatial distribution of accessibility, the areas with high accessibility score are distributed in the six core administrative districts of Beijing, accounting for 99.3% of the grids with high accessibility scores. When considering facility diversity, 46.7% of the grids within the core administrative districts experience an increase in their accessibility rank, and there is an increase in the number of grids with high accessibility. The research results indicate that considering facility diversity enhances the accessibility level of grids, elucidates the diversity differences in each area, and provides valuable information for the location selection of transit facilities and urban planning. The applicability of the proposed method to Beijing illustrates that it can provide valuable insights for the measurement of accessibility, which can help planners obtain more effective evaluation results.