Measuring the impacts of sidewalks on public transit first mile/last mile accessibility and their association with social and demographic factors

• This paper compares FMLM accessibility of sidewalk and road network. • Sidewalk network provides 45 % – 50 % less spatial coverage compared to street networks. • 39 % and 49 % of bus stops provide access to fewer groceries and healthcare facilities when following sidewalk networks. • A tier between the peripheral area and city-center exhibits a cumulative burden of poor sidewalk access and social vulnerability. Public transportation offers a sustainable, environment-friendly, and equitable mode of travel, particularly for marginalized and disadvantaged groups. However, the first-mile/last-mile (FMLM) access problem can pose significant challenges to its efficiency and ability to generate accessibility. An incomplete sidewalk network reduces transit accessibility by creating barriers, especially for sidewalk-reliant groups such as people with mobility disabilities, elderly, and school children. In this study, we develop new metrics to measure the impacts of sidewalk incompleteness on transit FMLM accessibility. Using data from Columbus, Ohio, USA, a typical mid-sized American city with an incomplete sidewalk network, we apply these measures and compare them to the sociodemographic characteristics of the neighborhood surrounding each stop. We find that the sidewalk network and high-quality sidewalk network have 45%-50% less spatial coverage around bus stops compared to street networks, respectively. 39% and 49% of bus stops provide access to fewer groceries and healthcare facilities, respectively, when following sidewalk networks. We observe that inner-city neighborhoods, despite being less affluent, often have better sidewalk access compared to affluent suburban areas. However, peripheral to city-center and less-affluent neighborhoods exhibit a cumulative burden with the poor sidewalk access that impacts access to essential resources such as groceries and health care. The research provides a direct and comparative measure of FMLM accessibility and suggests a strong linkage of urban morphology with sidewalk accessibility. This study calls for targeted sidewalk improvements and a nuanced understanding of accessibility gaps to promote equitable and efficient public transportation systems.