Air hubs tend to by points of convergence of regional services and gateways to international destinations. The location of an airport can be considered from three fundamental scales of interaction:
- Local. The location of an airport is subject to accessibility to its market area, implying that it must be easily reached by the airport’s customer base. Since airport sites have many constraints, they tend to be located at the fringe of the metropolitan areas they service. To alleviate this problem, many airports have been integrated to highway and railway systems, giving them a high level of local access and often becoming urban poles on their own right.
- Regional. The location of an airport fits in a network of passenger and freight air transport services. The first level of this network concerns the regional system where many airports act as hubs enabling to service smaller airports, usually within a flying time of less than two hours (short to medium ranges). Such connections are reflective of the interactions within an urban system and reflects the centrality of the airport city.
- International. Some airports are important gateways enabling to connect locations across continents with long range air services, which represents the third interaction scale. At this scale, other factor than centrality may be at play since some airports like Dubai offers a connectivity to intercontinental air transport networks.