Why is Atlanta the world’s busiest airport?

 Atlanta is home to one of the world’s largest airlines, Delta Air Lines

One might expect the world’s busiest airport to be located in New York or London or Beijing, but the distinction actually belongs to Hartsfield-Jackson Atlanta International Airport, located in the southern US city of Atlanta, Georgia. No matter which way you calculate it, Hartsfield-Jackson has been the world’s busiest since 1998. Not only does it attract more travellers than any other airport in the world (with about 92.4 million passengers passing through in 2011, the last full year on record), it also manages more aircraft movements (that is, more takeoffs and landings) than any airport in the world – with about 950,000 in 2010, also the last year on record.

All of this begs the question, why is Atlanta the busiest hub for air travel in the world?

Until 2012, Delta held the record for most annual traffic – measured by “revenue passenger miles” (RPM) – of any airline in the world. The metric of RPMs takes into account both the number of passengers carried and the distances an airline flew during a given year. In 2012 though, Delta’s RPM was beaten by United Airlines, which had grown in size following the 2010 merger between United and Continental Airlines.

So it makes sense, then, that Chicago, home to United’s headquarters, hosts the world’s second busiest airport as measured by aircraft movements – with 882,627 in 2010 – and the world’s fourth busiest as measured by sheer passenger numbers – with 66.6 million passengers in 2011. (The second and third busiest by number of passengers in 2011 are Beijing Capital International Airport, with 77.4 million and London Heathrow Airport with 69.4 million)

Hartsfield-Jackson serves 225 destinations in 51 countries, receives more than 250,000 passengers a day, and sees nearly 2,500 arrivals and departures per day. Out of this, Delta runs about 1,000 flights daily, serving more than 200 destinations.