Work on a fast transit railway linking south Beijing to the city's upcoming new airport began Monday.

The 41.36-kilometer new airport line will allow trains to run at maximum 160 kph, the fastest intra-city rail transit in the country.

The line will have just three stations. Passengers can check-in to their flights at the starting station -- Caoqiao -- located by the Third Ring Road and reach the airport terminal in just 19 minutes.

The line is being built by a public private partnership and will open in 2019 with the launch of the new airport, according to the state-owned Beijing Urban Construction Group.

Beijing's new airport is being built in the Daxing District to ease traffic at Beijing Capital International Airport. By 2019, the Chinese capital will have two major airports, one in the south and the other in the north.

The new airport will have four runways and can accommodate 620,000 flights per year by 2025. It will eventually handle 100 million passengers and 4 million tonnes of cargo a year.