Classifying airports according to their hub dimensions: an application to the US domestic network

Government agencies classify airports for different purposes, including the allocation of public funding for capacity developments. In a context of hub classification, determining the contribution of each airport to the national network in terms of the two dimensions of hubbing -i.e., traffic generation and connectivity- is a key aspect. In this regard, the choice of an appropriate connectivity indicator is still an unresolved issue. This paper adapts the well-known flow centrality indicator to an air transport context and develops a novel measure of airport connectivity. An application to the US domestic network is provided, using quarterly data on passenger demand to perform a detailed time-series analysis of airport connectivity patterns between 1993 and 2012. The flow centrality indicator is then used to define an alternative airport classification method within the context of the Federal Aviation Administration’s National Plan of Integrated Airport Systems (NPIASs). Results show that there is potential for improving the existing airport typology by explicitly separating connectivity and traffic generation as classification criteria.