Time-varying accessibility to senior centers by public transit in Philadelphia

Public transit offers older adults an important alternative travel mode for accessing social activity destinations. Given the growing size and socioeconomic diversity of the older population, transportation planners should consider how current urban transit systems can better meet their needs. In this study, we examine the time-varying accessibility to senior centers by public transit in each census tract of Philadelphia, Pennsylvania. Senior centers are community service and activity hubs for older adults which are typically overseen by the local area agency on aging. They offer a variety of services and social activities for older adults, including free meals, volunteering opportunities, information, and technology training. Using General Transit Feed Specification (GTFS) data and socioeconomic data from the U.S. Census Bureau, we analyze how accessibility varies across census tracts with respect to the tract's share of older adults, particularly those in vulnerable subgroups. We found that accessibility to senior centers declines from the downtown area to the suburbs but varies considerably among the vulnerable subgroups studied. We also found that when accounting for the open hours of senior centers, accessibility to senior centers is generally lower around midday (2 PM) than during peak hours (8:30 AM) on Mondays. We used the vertical equity index to examine social disparities in accessibility among older adults. We found that while SEPTA underserves neighborhoods with higher shares of older adults, tracts with higher shares of some vulnerable subgroups are better served than those with lower shares. Specifically, neighborhoods with higher shares of households that have no cars are better served than those with higher shares of African American and Hispanic older adults. These results suggest that the Southeastern Pennsylvania Transportation Authority (SEPTA) and the Philadelphia Corporation for Aging (PCA) should work together to better accommodate the diverse travel needs of older adults.