WUHAN, Jan. 25 (Xinhua) -- A double-deck rail-road bridge opened to traffic in southwest China's Chongqing Municipality on Thursday, according to the bridge's builder.

The 5.3-km bridge crosses China's longest river, the Yangtze. A four-track railway line sits on the upper deck, with speeds of up to 200 kph, and the lower deck has a twin-lane highway designed for trucks running at 120 kph, according to China Railway Major Bridge Engineering Group (MBEC).

"With a load capacity of 131 tonnes per meter, the bridge has set a new world record," said Wang Weifeng, spokesperson for MBEC.

The bridge is part of the Chongqing-Guiyang high-speed rail line.

The 345-km rail line will cut the average travel time between Chongqing and Guiyang, capital of southwest China's Guizhou Province, from 10 hours to around two hours.

China has the world's longest high-speed rail network. The country is expected to have 38,000 km of high-speed rail tracks by 2025, according to the China Railway Corporation.