Beijing, China (CNN) — China is poised to overtake the United States as the world's biggest air travel market by 2022 -- and it's little wonder the country's airport construction craze shows no signs of abating.

The government has plans to build or expand 74 airports nationwide by the end of 2020, aiming to accommodate a whopping 720 million passengers a year.

No project is attracting more attention than Beijing Daxing International Airport, the Chinese capital's new multibillion-dollar aviation hub slated to open in September 2019.

Bigger and busier

An image of the plan for Daxing Airport. Methanolia / Zaha Hadid Architects

Beijing is in desperate need of a second global gateway. The existing Capital International Airport is hitting full capacity, making it nearly impossible for airlines to add flights at desirable times.

In 2017, more than 95 million passengers passed through the three terminals of Beijing Capital, the world's second busiest airport behind only Hartsfield-Jackson Atlanta

The new Daxing airport, designed by the late architect Zaha Hadid and her Chinese partners, is built for the future, boasting four runways and a terminal the size of 97 soccer pitches upon opening of the first phase.

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The "modest" initial operational target is to accommodate 72 million passengers and two million tons of cargo annually by 2025.

The ambitious master plan calls for the building of a total of seven runways, and moving at least 100 million passengers and four million tons of cargo a year through the airport.

Construction for the $11.5 billion project began in 2014, with more than 40,000 workers currently on site. The nearly completed terminal bears all the hallmarks of Hadid's signature contour lines, with plenty of natural light shining through rooftop windows.

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Location, location, location

Nicknamed "starfish" by Chinese media for its shape of five concourses connected to a main hall, Daxing aims to reduce walking for passengers, long a complaint against many new mega-hubs.

The airport authority has promised a distance of no more than 600 meters between security checkpoints and the remotest gates.

Another passenger concern is Daxing's location: in the far south of Beijing, a city notorious for traffic jams. The new airport is some 50 kilometers from Tiananmen Square in the city center -- and even farther away from the main business districts in the east and north.

How Daxing Airport will look from the sky. Methanolia / Zaha Hadid Architects

Officials have brushed aside such worries, claiming they are building more than just an airport -- but rather a truly integrated transportation hub that would see high-speed rail, inter-city services and downtown-to-airport express trains all stopping right beneath the terminal.

Yet others say a new mammoth aviation hub will only worsen flight delays in Beijing, already ranked near the bottom of on-time performance list among airports worldwide.

While there is no indication that the Chinese military, which controls most of the country's airspace, will loosen its grip to give airliners more maneuver room, the airport authority insists Daxing's multi-directional runway design will improve operational efficiency in the air.

Tenant intrigue

For frequent fliers around the world, though, one big question lingers as the airport's much-anticipated opening approaches: Which airlines will use Daxing?

It was going to be a crown jewel for Skyteam, one of the three global airline alliances, with China-based members China Southern and China Eastern becoming anchor carriers at Daxing. Other Skyteam members such as Delta, Korean and Air France-KLM will move to the new airport as well.

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China Southern, however, announced in November that it would leave Skyteam by the end of 2019. The airline subsequently signed an agreement with American, a member of rival Oneworld alliance, for closer cooperation.

Adding another twist to the confusing plot, Air China -- the country's flag carrier and a Star Alliance member -- is supposed to remain at the current Capital International Airport along with other Star carriers, but it recently revealed plans to have a subsidiary based at Daxing.