On what does the size of a hub airport predominantly depend?

The size of a hub airport predominantly depends on the percentage of enplanements. Enplanements refer to the number of passengers who board an aircraft at a given airport and are a direct indicator of an airport's capacity and operational scale. A hub airport serves as a central point for connecting flights and is typically characterized by a high volume of enplanements, which facilitates its role in accommodating more flights and passengers.

The significance of enplanements stems from the fact that they indicate demand for air travel at that airport, influencing how airlines allocate resources, such as additional flight routes, terminal capacity, and overall operational investment. A higher percentage of enplanements can lead to increased funding, better facilities, and expanded services, enabling the airport to grow in size and importance within the air transportation network.

Other factors, while relevant, do not play as critical a role in determining the hub airport's size. For instance, the number of runways impacts an airport's operational capacity but does not necessarily reflect its role as a hub. Geographic location is essential for strategic positioning but is not a direct measure of size. Annual revenue is an important metric for financial health, but it is largely influenced by the volume of enplanements rather than determining the airport's size itself