A total of 7.8 million trips are expected to be made by train on Wednesday as millions return to work from Spring Festival holiday reunions, according to the China Railway Corporation (CRC) on Wednesday.

The CRC said it would operate 720 extra trains on Wednesday to cope with the travel peak after 6.96 million train trips were made on Tuesday, about half a million more than the previous year.

The week-long Spring Festival, the most important traditional holiday in China, will end on Thursday and tens of millions of people will return to work from their hometowns.

China's transport system is put to the test during "Chunyun," which literally means "Spring Festival transport," the 40-day travel period around the Spring Festival.

During the first 20 days of Chunyun ending Tuesday, about 121.22 million trips were made by train, up 13.6 percent from the same period last year, according to the CRC.

About 3.62 billion trips are expected to be made during the 40-day period, which started in mid-January, according to official data.

Bad weather has put even more pressure on the country's transportation system. China's meteorological authority earlier on Wednesday issued a yellow alert for blizzards that are expected to sweep the country's central and eastern regions.

Snow on the ground in some regions could be as thick as 16 cm, leading to icy roads, the National Meteorological Center said.