Distance-dependent patterns of intercity passenger mode share: A multiscale analysis of socioeconomic and spatiotemporal heterogeneity.

The intrinsic attributes of different transportation modes render travel distance a major factor of intercity passenger mode share; yet systematic examination of how this distance effect varies across multiscale contexts remains limited. Therefore, this study investigates how travel distance regulates the shares of highway, railway, and aviation modes in intercity transportation system, and examines the underlying dynamics across multiscale socioeconomic and spatiotemporal contexts. Using nationwide Location-based Services (LBS) data collected from China, polynomial fitting models were constructed to establish the relationship between travel distance and multi-modal shares. Our results demonstrate the significant role of travel distance in shaping intercity passenger mode shares, with effects that vary substantially across different contexts. Temporally, highway mode share rises for short-to-medium trips during holiday periods such as Spring Festival Travel Rush, while aviation always dominates for long trips. Spatially, Northeast China exhibits railway dominance, coastal regions concentrate aviation flows, while Southwest China depends on highways for short-distance connectivity. From the socioeconomic perspective, urban areas with higher economic level, administrative rank, and larger population exhibit elevated aviation shares and diminished highway shares. Our empirical findings advance understanding of nonlinear distance-modal share relationships considering socioeconomic and spatiotemporal features, thereby informing multimodal transport planning and cross-regional resource optimization in intercity transportation system.