BEIJING, Dec. 29 (Xinhua) -- The expressway linking Beijing's new airport on the southern outskirts is expected to open in June 2019, the Beijing Municipal Commission of Transport announced Saturday.

Construction of the expressway has gained momentum, the commission said. Beijing Daxing International Airport is scheduled to start test operation by September next year.

The expressway will start from Tuanhe Bridge near the city's South Fifth Ring Road and end at the north side of the new airport. The expressway is 27 km in length and will have four lanes in each direction.

The new airport is located 46 km south of downtown Beijing, and designed to take pressure off the overcrowded Beijing Capital International Airport in the northeastern suburbs.

The construction of the main terminal's exterior walls has wrapped up, while workers have finished around 80 percent of interior decoration, with the electromechanical devices having been installed, according to Li Jianhua, who is in charge of the new airport's terminal project under Beijing Urban Construction Group.

A subway linking Beijing's urban districts with the airport is also being built. A high-speed railway will be built to connect the airport with Tianjin, 120 km east of Beijing, sources with the transport authorities of the two cities said earlier this month.