Analyzing sustainable competitiveness of inter-city coach from the impact of high-speed railway opening in Jiangsu Province, China

High-speed railway (HSR) decreases the geographic and temporal constraints between cities, which may exert influence on inter-city transportation market. The impact of HSR on airlines has been well studied, while studies relevant to its positioning and relationship with inter-city coach (ICC) are limited. Based upon a four-year longitudinal panel dataset of ICC in Jiangsu Province, China, we utilize a difference-in-differences (DID) method to explore the effects of HSR opening on measuring the sustainable competitiveness of ICC. The results show that the HSR opening dramatically reduces ICC volumes. By further exploring the effect of service differences, we construct continuous DID models and find that ICC passengers are more concerned about travel time than price. Furthermore, the influence of HSR on ICC routes is not statistically significant for distances within 100 km, but becomes significant for distances exceeding 100 km, with the most pronounced impact observed on routes surpassing 150 km in length. In addition, we find that the ICC volumes of feeder routes overlapping with HSR service have decreased, while those without HSR service have tended to increase. The findings of this study could provide beneficial insights into the sustainability and coordinated development of inter-city transportation services.