The definition of the world's busiest airport has been specified by the Airports Council International in Geneva, Switzerland. The ACI defines and measures the following three types of airport traffic:
- Passenger traffic: total passengers emplaned and deplaned, passengers in transit counted once
- Cargo traffic: loaded and unloaded freight and mail in metric tonnes
- Traffic movements: landings and take-offs of aircraft
Busiest airports 
The following airports make claims based on objective volume measures that are defined above:
- Largest number of passengers annually (1998–present);
- Most aircraft movements annually (1999–2000, 2005–present); In 2007, Hartsfield again set the world's record for most aircraft movements in one year with 994,346.
- Most cargo traffic by weight annually (2010).
- Largest number of passengers annually in all city airports combined (2010).
- Largest number of international passengers annually (2004–present).
Historical claims 
- In the late 1940s, Chicago Midway was the busiest airport in the United States by total aircraft operations – i.e., including every training aircraft practicing take-offs and landings. New York LaGuardia had the most airline operations and passengers until the early 1950s, when Chicago became the busiest airport in the United States by any criterion. Before World War II, Chicago Midway was the origin or destination of one in four U.S. airline flights, although a 1939 Official Aviation Guide shows more airline flights scheduled at Newark than at Chicago.
- As the home of Fedex Express, Memphis had the largest cargo operations worldwide from 1993 to 2009. It remains the busiest cargo airport in the US and the Western Hemisphere.
Non-standard claims 
- The world's busiest airport by traffic movements during the seven-day EAA AirVenture Oshkosh event. 25,000 traffic movements are handled in a week during the yearly event, and air traffic controllers are picked by a competitive selection process to handle this traffic. During the event, a banner reading "WORLD'S BUSIEST CONTROL TOWER" was hung from the control tower.
- Gatwick has the world's busiest single-use runway. It does have two runways on site but the close proximity of the two and the length and lack of guidance for the second means that only one is used. It is London's second largest international airport and second busiest by total passenger traffic in the United Kingdom after Heathrow.
See also 
External links