Beijing has begun to work on five more subway lines, which will have a combined length of 126 kilometers and will link the megacity with its ever expanding suburban areas.

On Friday, the city's key project construction headquarters announced that construction had begun on the southern extension of Batong Line; the southern extension of Changping Line; the Pinggu Line; the New Airport Line (phase one); and No.three Line (phase one).

Among the new lines three stretch to the east, through and around Tongzhou district where Beijing's second administration center will be based. The eastern suburb is close to Beijing's CBD.

Another line connects the city center to Beijing's new airport, located 46 km to the south. The airport, designed to handle 100 million passengers a year, will be finished in 2019.

The fifth line connects Beijing's northwestern area, where universities, research institutes, and many tech startups are based.

The new lines will be operational between 2019 and 2021.

Source: english.qianlong.com