Thirty-five cities on the Chinese mainland have got the green light to build nearly 6,000 km of urban rail lines, according to the China Communications and Transportation Association. The estimated cost of the lines will be about 1.3 trillion yuan ($212 billion).

Urban rail transit systems are under construction in 30 cities, said the association, which will sponsor the Metro China 2013 between Nov 11 and 22 in Beijing, a major exhibition to look at the future of rail.

The association said that as of the end of 2012, China��s urban rail systems, including subway and light rail, reached 1,980 kilometers in length, operating in 16 cities.