Research hotspots and prospects of the air-rail integrated hub
The construction of air-rail integrated hubs represents a transformative shift in regional transportation systems because they serve as a vital support and guide for regional socioeconomic development.However,academic interest in these hubs is lacking and research findings fall short of addressing practical development needs.To provide a scientific foundation and reference for future studies,this paper systematically reviews the research findings on air-rail integrated hubs in recent years,identifies current research hotspots,and offers scientific perspectives for future research.The results show that:(1)These hubs effectively integrate the air transport network with the high-speed railway network,facilitate the rational allocation of transportation resources,optimize the comprehensive transportation system,and develop regional socioeconomic activities.These hubs exert diverse spatial effects across the hub area,their host cities,and cities along the transportation routes.(2)Existing studies on air-rail integrated hubs primarily focus on five areas:the conceptual definition,intrinsic aspects(e.g.,organizational models,site selection and layout,and passenger transfers),external effects(e.g.,spatial and regional effects),environmental and social welfare,as well as their cost-benefit analyses.(3)Future research areas include:the relationship between China's air-rail integrated hubs and urban regional economic development;the trend toward hierarchy and networking in air-rail integrated hubs;the impact of air-rail integrated hubs on human-land relations;the linkage between air-rail integrated hubs and the advancement of new productive forces;and a comprehensive review of development experiences and the establishment of policy frameworks for China's air-rail integrated hubs.Moving forward,China must develop a systematic theoretical and methodological framework for research on air-rail integrated hubs and enhance global dialogue in this field of study.