"It's still very hard to buy tickets during the peak period, although the whole booking system and conditions for train tickets have been improved," said Yang Shuifeng, a female migrant worker in Shanghai who failed to get a train ticket back home for Jan 20 after waiting for hours on Monday.

She had to come back to the ticket booth early on Tuesday morning for a ticket for Jan 21.

Demand for buses, an alternative choice for passengers who failed to get a train ticket, went wild even earlier.

"On Jan 1 we started selling bus tickets with a 24-hour service," said Zhang Yongbin, director of Shanghai General Long-Distance Bus Station.

By Monday afternoon, the station had sold 40,000 tickets to more than 100 destinations.