China's first subway line to cross the Yangtze River, the country's longest waterway, starts test run on Dec 28 in the central city of Wuhan, Xinhua reported Thursday.

Wuhan subway Line 2, China's first subway line to cross the Yangtze River, starts test run on Dec 28 in the central city of Wuhan. [Photo/Xinhua]

Subway trains have run through the 27.73-km tunnel for Wuhan Line 2, which links Wuchang and Hankou - two major areas of the city - over the past three months. But passengers are only allowed to board the trains on Dec 28 when the test run starts.

As a key transportation route, the line is expected to handle half of the city's cross-Yangtze traffic flow, easing gridlock on bridges over the river. It only takes three minutes to cross the river.

The construction costs around 14.9 billion yuan ($2.37 billion), according to estimates by previous reports.

It will be Wuhan's first subway, which is estimated to transport at least 500,000 passengers daily.