Of the passengers, about 80 percent were flying on hub carrier Delta Air Lines or a Delta Connection carrier. About 9.7 percent were passengers on Southwest Airlines, the second-largest carrier at Hartsfield-Jackson.

About 2.8 percent flew on American, 2 percent on United, 1.8 percent on Spirit and 1.1 percent on Frontier. All other carriers made up less than 1 percent.

Last year, Hartsfield-Jackson officials had decided that the airport preferred to be known as "world's most traveled."

But after Reed announced the airport's repeat title this week during his State of the City address, the airport didn't shy away from the "world's busiest" phrase in its announcement of nearly 104.2 million passengers in 2016.

Hartsfield-Jackson also said it handled more flights than any other U.S. airport, with a total of 898,356 flights at Hartsfield-Jackson last year.

About the Author

Kelly Yamanouchi

Business reporter Kelly Yamanouchi covers airlines and the airport including Atlanta-based Delta Air Lines, one of the world's largest carriers, and Hartsfield-Jackson, ranked for years as the world's busiest airport. She has covered airlines for more than 15 years, graduated from Harvard and has a master's degree from Northwestern.