Beijing, Dec 12 (IANS): The first subway line to cross China's longest waterway, Yangtze river, is all set to open in the central city of Wuhan.

The 6,300-km Yangtze river originates in northwest China's Qinghai province and flows through 10 provinces and municipalities before flowing into the East China Sea. It is a major transport link between the west and east China.

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. The construction costs around 15 billion yuan (around $2.5 billion), according to estimates by previous reports.

It will be Wuhan's first subway which is estimated to transport at least 600,000 passengers daily by 2015. The test run is expected to begin this month.

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 last three months. But passengers will only be allowed to board the trains Dec 28 when the test run starts, according to Hubei provincial transportation officials.

The subway line recently passed the experts' assessment, officials added.