Exploring accessibility from spatial interaction data: An evaluation of the Essential Air Service (EAS) program in the contiguous US air transport system

This paper is primarily concerned with the accessibility of airports located in small and geographically isolated communities. Specifically, it carries out a sensitivity analysis to derive rates of change for the parameters of a spatial interaction model applied to empirical air passenger trip data, and interprets the results focusing on the local airports subsidized by the Essential Air Service program. An empirical trip based accessibility measure is developed for individual airports in the contiguous US air transportation system. The measure enables us to capture the distinctive roles of small airports, which primarily function as regional associates of nearby cities and entrances for long-haul trips via major hub(s) to continental-scale connections. We observe the geographic and temporal variability of accessibility among airports, regarding the external factors including the dynamics of air carriers’ routing schemes, as well as global and local circumstances. Their impacts on passenger journey lengths are substantial at the local airports due to the few available connections. This issue has received less attention in existing subsidy program assessments. Furthermore, we explore the geographic distribution of non-subsidized local airports showing similar accessibility conditions. This paper enhances prior development by showing that the rates of change in accessibility scores are largely stable over recent national air passenger data.