Revealing the functional roles of global airports through passenger flow: A higher-order network perspective

Understanding the functional roles of airports in the global air transport network (ATN) is essential for improving system efficiency and performance. However, existing research have largely focused on the network’s topological characteristics, lacking an operational perspective that incorporates passenger flows. Meanwhile, conventional pairwise network modeling methods often overlook higher-order dependencies in passenger itineraries, such as their sequential order, which may lead to misjudgments of airport importance. To address this gap, we construct a higher-order ATN framework integrating global passenger flow data to capture travel behaviors with path dependencies, and employ multiple metrics tailored to this framework to reveal the functional roles of airports across three dimensions: transfer role, cross-community bridging role, and central role. Based on data from October 2023, the empirical analysis identifies 11 key airports that serve as indispensable bridges for maintaining cross-community passenger accessibility. It also reveals pronounced spatial disparities in airport functional importance, with airports in North America generally occupying core positions, while those in Asia, Africa, and South America tend to be more peripheral. When switching from conventional to higher-order networks, 22% of airports undergo substantial changes in importance rankings, and more than 75% experience declines in importance values. The study further compares global airport metrics with their counterparts in October 2019 and identifies several potential factors influencing airport functional roles. These results highlight the advantages and necessity of the proposed approach, providing strategic guidance for airport development planning and global ATN optimization. • We build a global higher-order air transport network using passenger flow data. • Path-dependent modeling reveals airports’ functional roles beyond topology. • Marked spatial disparities emerge in the functional importance of global airports. • Results challenge the equivalence of functional and topological airport importance.