Sustainable urban development stands as a pivotal imperative in contemporary discourse. One of the world's largest megacities, Dhaka, faces immense social sustainability challenges due to rapid urbanization for both present and future generations. As Dhaka's urbanization accelerates, transportation availability has become a pressing concern for socially sustainable urban areas. This study aims to investigate the current conditions of transportation availability and its impact on socially sustainable urban development, particularly in developing cities. This study used a quantitative research approach, and Dhaka is considered a representative city in a developing region. A multistage sampling method was used to collect 564 responses from residents of Dhaka through a structured questionnaire survey. The results indicated that four indicators of transport availability in Dhaka city exhibit low satisfaction levels among residents. Additionally, transportation availability statistically impacts Dhaka's socially sustainable urban development, as determined using four indicators cross-section OLS and Poisson regression analysis. The results guide governmental bodies, legislators, and urban planners in pursuing socially sustainable cities. Moreover, transportation availability indicators offer actionable policy insights for urban sector strategies in developing nations, bridging urbanization and sustainability to advance SDG-11 (Sustainable Cities and Communities) in the 2030 Agenda.