Analyzing the accessibility of subway stations for transport-vulnerable population segments in Seoul: Case of bus-to-subway transfer

With the increasing interest in smart card data and transport-vulnerable population segments, data-based analysis has become increasingly important. This study aimed to design transfer trips by using smart card usage data to analyze vulnerable transfer routes for each user group. After merging smart card and basic information data such as stops, stations, and facilities, we constructed a transfer dataset of individual users according to the specified transfer time ranges and conditions. The transfer analysis targets were limited to transfers between the bus and subway, and transfer patterns for each user group (general population, youth, children, elderly, and disabled) were analyzed by date and time. The analyzed populations were then divided into general and vulnerable groups, and vulnerable transfer routes were identified. The actual transfer time differences between the general and vulnerable groups were then analyzed. We directly measured the expected transfer time differences between these groups based on map data and different walking speeds. We then calculated the differences between the expected and actual transfer times and analyzed the correlation between the number and location of accessible facilities in subway stations. We hope that this analysis will be useful for guiding the installation of accessible facilities in subway stations.