Assessing Equity of Vertical Transport System Installation in Subway Stations for Mobility Handicapped Using Data Envelopment Analysis

With a rise in the number of elderly, and disabled individuals, there has been an increased focus on the mobility rights for mobility handicapped users. The subway is one of the most popular transportation modes for these groups, i.e., elderly and people with disability. The availability of vertical transport systems such as elevators, wheelchair lifts, and escalators in subway stations is crucial for their use of the subway. This study aims to evaluate the equity of the subway station regarding the installation of vertical transport systems using smart card data and open data sources in Seoul. Equity was defined as the number of vertical transport systems installed compared to the subway station attributes, including number of mobility handicapped user trips and station conditions. As a result, the proposed model estimated that the equity score for the subway stations was 0.48 on average. Out of 257 stations, 27 were found to be equitable with an equity score of 1.0. The equity score for the bottom 27 stations was 0.19 on average, meaning that 81% of facility improvement is needed to achieve an equity score of 1.0. Also, a practical application was performed to validate the proposed model. It was found that the proposed strategy was effective and efficient in enhancing the equity of vertical transport systems and saving costs for facility improvements. These findings suggest that investing or allocating facilities based on the needs of each station can lead to more equitable and efficient improvements in equity.