Running miles to the connecting gate, elbowing your way in the boarding line, and a 20 minute search for the right ticket line are just some characteristics of the world's busiest airports in 2011.

All of the long lines and crowded terminals may be worth it to get to some of the most popular tourist destinations in the world like London or Paris. But, there are also some surprises, especially for those who don't travel through them. Take Atlanta's Hartsfield-Jackson International for example. Oddly enought, Atlanta's airport is the consistent king of busiest airports.

In order to determine the busiest airports, data from the Airports Council International (ACI) was used for the year to date (Jan to July). Their data is calculated by the total number of passengers who departed and arrived, with those in transit only counted once. The final totals for 2011 will be released early next year.

For over 10 years, Atlanta's Hartsfield-Jackson International Airport has remained the busiest airport, and 2011 is no exception. Almost 90 million passengers traveled through Atlanta in 2010. Although Atlanta remains on top, Beijing's Capital International is closing in, with almost twice the growth of Atlanta.

In 2010, Beijing made its move to second place, sliding past London's Heathrow. Beijing has grown to become a major hub in the Asia Pacific region due to China's increasing economic strength. China's large population and rising affluence also plays a role in the surge of travel.  

Possible reasons for the Heathrow's downward slide included the Icelandic volcano ash and harsh winter storms, which continued into the beginning of 2011.

The U.S. continues to dominate the top 10 with five international airports on the list: Hartsfield-Jackson Atlanta, Chicago O'Hare, Los Angeles, Dallas Fort Worth, and Denver.

Interestingly, none of these U.S. airports made it onto the ACI list of busiest airports in terms of International Freight Traffic. The leaders of that list are as follows: Hong Kong International Airport, South Korea's Incheon Airport, and Shanghai Pudong International Airport.

Press Start to view the slideshow of the World's Busiest Airports in 2011.