Evaluating Changes in Spatial Accessibility to Airports in Turkey between 2000 and 2018

Abstract

The present study aims to investigate the changes that occurred between 2000 and 2018 with regard to spatial accessibility to airports for each district in Turkey. Within this scope, first, the service coverage area of each airport within 1 to 2 h travel time by car for 2000, 2009, and 2018 using the available road networks for the given years is evaluated and each district that can reach at least one airport within 1 to 2 h by car determined. Secondly, the catchment areas of each airport are defined based on geographical distribution and the catchment populations of airports found. Thirdly, the regionalization coefficient for each airport in the given years is calculated to understand the availability of each airport by comparing the catchment area population with the number of domestic passengers. Finally, a gravity-based formula is employed to measure the spatial accessibility value of each district to the airports within the catchment area of 2 h travel time in the given years. The main findings from the study provide clues about the direction of future policies. The last airports to open have reduced the maximum distance covered, especially in eastern Turkey; consequently, airports' catchment populations have shrunk. However, the regionalization coefficients of airports located in regional centers and hub cities have increased in consequence of the increase in the number of air passengers over the given period. In summary, travel time to main hubs and airports' total catchment populations have had combined effects on the number of air passengers and spatial accessibility values of districts in Turkey.