Numerous cities in developing countries in Asia have focused on building rail transit networks using the transit-oriented development (TOD) policy to improve urban accessibility through public transportation. However, the hypothesis that expanding rail transport networks and implementing TOD policies will improve urban accessibility in developing cities has not been sufficiently analyzed. Therefore, this study selected four Asian cities of various sizes under different stages of development to explore how the expansion of rail transport networks and implementation in high-density development of the three TOD policies affect urban accessibility. The results suggest that rail transit network expansion would significantly increase overall accessibility, and TOD policy implementation would further increase accessibility in all cities. This study clarified that the desired urban structure of each city, which determines accessibility, significantly differs depending on the size of the city and existing and proposed networks. © 2023 The Authors