Separate yet Interdependent Networks: The Structure and Function of European Air Transport

Air transport plays a crucial role for connecting people around the globe. Existing network studies often consider only flight networks. However, another important aspect of air transport is the passenger flow from origin to destination – a separate yet interdependent network. This study argues that for a comprehensive study of air transport, both aspects should be taken into account. These networks represent the structure and function of a complex system. The framework of function-structure networks provides a formal model to describe large-scale networked systems. To demonstrate the approach, the global and local properties of the function and structure of European air transport are investigated. This paper also proposes an adjusted betweenness centrality metric and other centrality metrics that can help explain anomalies found in previous investigations of air transportation systems