The networkability of cities in the international air passenger flows 1992–2004

A modified social network analysis model was designed in this study for use in the examination of the international air network. By using this model in analyzing the networkability of cities, the connectivity of the air routes was estimated, using the air traffic and the number of air routes. Networkability is the quantitative measurement of the spatial interaction relationships in the international air network. Through this process, this study aims to analyze the structural changes of the global network in 1992 and 2004. As a result, it was observed that London, Paris, Frankfurt, Amsterdam, and New York were class 1 cities that were at the top in both years. Tokyo was included in class 1 in 1992, but not in 2004. Rome, Zurich, Singapore, Los Angeles, and other cities were identified as the class 2 cities in 1992, while Singapore, Tokyo, Madrid, Hong Kong, Bangkok, etc. were identified as the class 2 cities in 2004. These cities occupy the center of the global network, and the class 1 cities are connected to the class 2 cities, which perform the function of hubs in each continent, thus uniting the whole world as one network.