Exploring public transport accessibility equity to railway stations under travel time uncertainty

The equity of public transport accessibility is vital for promoting fairness and sustainable development. While many studies have examined accessibility inequities, few focus on inter-group and intra-group disparities. This study assesses public transport accessibility to a high-speed railway station (HSR) for different income groups in Nanjing, China, using total travel time to the station as an indicator. Results show that accessibility during the morning peak (8 AM) is lower than at night (10 PM). Population density is positively correlated with accessibility. High-income groups have the highest accessibility, low-income groups the lowest. Theil index shows highest equity in high-income groups, and lowest in median- and low-income groups during peak and night hours, although bootstrap tests show no statistical significance, these trends still reflect intra- and inter-group disparities. Underserved areas are mainly in low-income neighbourhoods. These findings provide a basis for policies to improve equity in public transport.