Beijing inched one step closer to taking the crown for the world's busiest airport.

As the ranks of the Chinese middle class swell and more people take to the skies, passenger traffic at Beijing's international airport rose to a new record of 95.8 million last year.

This increase at the world's second-busiest air hub -- at least the fifth straight year of gains -- has allowed Beijing Capital International Airport to narrow the gap with top placed Hartsfield-Jackson Atlanta International Airport, whose passenger numbers fell in 2017.

China is forecast to overtake the U.S. as the world's biggest air-travel market as soon as 2022. To cope with the surge in fliers, Beijing is building a US$12.9 billion mega airport in a southern suburb that's scheduled to open next year. It would accommodate as many as 100 million passengers annually, with the existing and new airports likely sharing 170 million travelers a year by 2025, according to official estimates.

The new airport has been designated by authorities as the hub for members of the SkyTeam alliance, a global group of airlines that includes China Eastern Airlines Corp. and China Southern Airlines Co. The two state-owned Chinese carriers will each be allowed to capture 40 percent of the airport's passengers, gaining coveted time slots to Europe and the U.S. in flag carrier Air China Ltd.'s backyard.

Beijing will also be joining a select list of major cities with two or even three international airports, including London, New York, Tokyo and Paris. Unlike in Beijing, though, those airports usually take complementary roles, such as one serving international or intercontinental routes and the other focusing on domestic or regional flights.