Shared micro-mobility meets bus: A spatiotemporal heterogeneity analysis in Chinese medium-sized cities

When the rapidly expanding shared micro-mobility (SMM) system meets bus network, it introduces both new opportunities and challenges to medium-sized cities where transportation dynamics differ significantly from those in larger urban areas. To comprehensively understand the impact of SMM on bus ridership while accounting for spatiotemporal heterogeneity and unidirectional time effects, this study employs the Unidirectional Geographically and Temporally Weighted Regression model to analyze the influence of the SMM system—comprising free-floating bikeshare (FFBS), station-based bikeshare (SBBS), and electric free-floating bikeshare (E-FFBS)—on bus ridership in Yancheng, a representative medium-sized city in China. The results suggest that the SMM system is negatively associated with bus ridership overall, with heterogeneity across modes and spatial contexts. FFBS and SBBS exhibit positive associations, particularly in peripheral areas, while E-FFBS shows a negative association in both central and peripheral zones, attenuated in areas with well-developed bus networks such as the southern new urban district. Ridership levels also differ across land-use types, with commercial zones aligned with lower usage, while residential, employment, and educational areas exhibit stronger bus utilization. Demographic segmentation indicates that young adults are generally linked to lower bus usage, except in areas with high-quality services. Weekday–weekend comparisons reveal that the favorable linkages of FFBS and SBBS with bus ridership are less salient on weekends, while the presence of E-FFBS more consistently corresponds to reduced usage, likely due to leisure-oriented travel. This study not only enriches the literature on medium-sized cities but also offers a transferable framework for examining similar urban contexts.