Noreen McDonald-PI. With nationwide declines in public transportation ridership, transit may be falling behind in its ability to help cities deal with congestion. Increasing real-estate values are causing the economic displacement of low-income populations, those most closely associated with transit ridership. A plethora of new mobility options are providing alternatives for transit riders who can afford them. But how will access to transit, ridership and congestion be impacted by these shifts in demographics and the introduction of new mobility services? This project includes researchers from four universities in the STRIDE (Southeastern Transportation Research, Innovation, Development and Education Center) partnership that together will address access to public transportation issues with specific contributions in suburbanization of poverty, Transportation Network Companies (TNCs), health care access and vulnerable populations. In thrust 1, a methodology will be developed to assess the externalities of the phenomenon of suburbanization of poverty with respect to access to public transportation. In addition, this thrust will provide a detailed analysis of sociodemographic and accessibility changes over time. In thrust 2, the study team will provide a model for transit ridership on a highly specific spatial and temporal scale to provide useful insights on the impact of service allocation policies and conflicting competition and complementarity happening with TNCs. In thrust 3, the study team will develop a better understanding of the interactions between public transit and TNC providers. In thrust 4, the study team will document the rapid evolution of paratransit services available to access health care. Although the research in all four thrusts focuses on specific areas of the southeast US, the results will be applicable nationally to aid transit and regional planning agencies.