The dynamic effects of regional public transport connectivity on intercity mobility from a dyadic flow perspective

The advancement of high-speed transport and communication technologies is making intercity mobility a key factor driving socio-economic development. However, systematic analysis of how high-speed rail (HSR) and air transport connectivity impact intercity mobility is still limited. To fill this gap, this paper conducted an empirical analysis of the intercity mobility impact - and its spatiotemporal heterogeneity - of HSR and air transport. Baidu migration and transport services data for holidays and weekdays in 2023 were collected as a sample. The results indicated that short and medium distance travel was more prominent on holidays, while long-distance travel predominated on weekdays. The impact on intercity mobility of HSR and air transport was more related to improving connectivity rather than a simple opening of HSR and air transport. Connectivity increase by HSR resulted in a larger increase in intercity mobility than that of air transport during both holidays and weekdays. HSR and air transport connectivity has generated uneven intercity mobility effects concerning the city-pairs in different regions and distance ranges. The benefits of HSR extend beyond short and medium distances to include longer distances of 1000–1500 km. These implications are useful for high-speed transport planning to improve the adaptability between transport supply and demand.