Evolving trends and gaps in transit accessibility index research in Asia: a bibliometric analysis

Transit Accessibility Index (TAI) has become a key tool for evaluating how effectively public transport systems connect populations to essential opportunities in rapidly urbanising Asian cities. Despite increasing scholarly attention, existing studies remain fragmented, geographically concentrated, and methodologically constrained, limiting the development of context-sensitive and equity-oriented frameworks. This study addresses these limitations through a bibliometric analysis of TAI research in Asia from 2002 to 2024, based on 260 publications indexed in Scopus. The analysis examines publication trends, geographic distribution, collaboration networks, and thematic evolution. Results indicate significant growth in research output, reflecting the integration of accessibility into sustainable mobility and transit-oriented development agendas. However, research remains concentrated in a few countries, while collaboration is largely intra- national, limiting regional knowledge exchange. Thematic analysis reveals a strong focus on spatial accessibility and system performance, with limited attention to equity, informal mobility, and climate resilience. Although data-driven approaches are increasing, their application remains uneven. This study provides a systematic synthesis of TAI research in Asia and highlights the need for more inclusive, multidimensional, and context- sensitive accessibility frameworks to support sustainable urban planning