“Crown shyness” in intercity airport shuttle services: A spatial econometric analysis of the Yangtze River Delta airport cluster

This study investigates the phenomenon of “crown shyness” for intercity airport shuttle services in the Yangtze River Delta Airport Cluster, China. The concept, derived from forest ecology, is applied to describe the non-overlapping nature of shuttle bus routes between airports in overlapping catchment areas, where airports may withdraw services to avoid direct competition. The research employs spatial zero-inflated negative binomial mixed models (SZINBMMs) to analyze daily shuttle bus route frequencies, examining the factors that influence both the initiation and service levels of these routes. The analysis reveals a “crown shyness” pattern, particularly in areas with competing airport sub-clusters, characterized by an inverted U-shaped relationship between the service initiation probability and route length. Our findings indicate that spatial correlations, economic factors, and airport characteristics significantly impact shuttle service distribution, providing insights into the complex dynamics of airport catchment area connectivity. The study concludes with policy implications for the strategic planning and development of multi-airport systems and world-class airport clusters, emphasizing the importance of considering ground access services.