Workers lay tracks for the Shanghai-Nantong Yangtze River Bridge on Dec 14. [Photo/WeChat account: zjgcitynews]

Railway tracks began being laid for the Shanghai-Nantong Yangtze River Bridge on Dec 14.

The bridge, which links Zhangjiagang, Suzhou with Tongzhou district, Nantong, is the world's largest road-rail cable-stayed bridge, with a length of more than 11 kilometers and a main span of 1,092 meters. Its main tower stretches 330 m into the sky.

The bridge features a six-lane expressway on its upper deck and four railway tracks on its lower deck. Among the four railway tracks, two will serve for the Shanghai-Nantong railway line, which has a designed speed of 200 km per hour, while the other two will serve the Yancheng-Nantong high-speed railway line, which has a designed speed of 250 km per hour,

Track-laying for the main span is expected to be completed on Dec 20 and be followed by the installation of a train control system.

Construction on the bridge started on March 1, 2014, and the final section was connected on Sept 20 this year.

According to authorities, the bridge is projected to be finished on March 20, 2020 and begin operating on July 1 of the same year.