Railway cargo volume in 2015 dropped nearly 12 percent from a year ago, the biggest fall on record. In the first quarter of this year, the drop slowed but still, volume slipped 9.4 percent year on year.

Coal and iron ore are two main cargo items transported by rail in China. Cutting overcapacity in steel and using more environment-friendly energy weakened demand for coal and iron ore. Last year, the volume of coal transported by rail fell more than 12 percent year on year.

In the past ten years, China's annual railway transportation volume increased gradually from 2005's 2.7 billion tonnes to the highest reading of 3.97 billion tonnes in 2013. Then the figure began to drop as commodities demand slowed.