Thousands of passengers
|Total enplanements||Large hubs||Medium hubs||Small hubs||Nonhubs|
NOTES: Data are for all scheduled and nonscheduled service by large certifi cated U.S. air carriers at all domestic airports served within the 50 states, the District of Columbia, and other U.S. areas designated by the Federal Aviation Administration (FAA). Not all scheduled service is actually performed. Moreover, for several years, total performed departures exceed total scheduled departures because nonscheduled departures are included in the totals. Prior to 1993, all scheduled and some nonscheduled enplanements for certifi cated air carriers were included; no enplanements were included for air carriers offering charter service only.
Air traffic hubs are designated as geographical areas based on the percentage of total passengers enplaned in the area. Under this designation, a hub may have more than one airport in it. (This definition of hub should not be confused with the definition used by the airlines in describing their "hub-and-spoke" route structures). Individual communities fall into four hub classifi cations as determined by each community's percentage of total enplaned revenue passengers in all services and all operations of U.S. certificated route carriers within the 50 states, the District of Columbia, and other U.S. areas. Hub designation is based on passenger boardings at individual airports as designated by the FAA. Classifications are based on the percentage of total enplaned revenue passengers for each year according to the following: 1 percent or more = large, 0.25 to 0.9999 percent = medium, 0.05 to 0.249 percent = small, less than 0.05 = nonhub.
SOURCE: U.S. Department of Transportation, Research and Innovative Technology Administration, Bureau of Transportation Statistics, National Transportation Statistics, table 1-34, available at http://www.bts.gov/publications/national_transportation_statistics/ as of August 2008.