In China, hundreds of millions of young people found job opportunities by working in factories or offices in bigger cities. Therefore, every Chinese New Year, they need to travel back to their home provinces, to meet their families and friends. This has created the largest seasonal human migration in the world.
In 2017, the Transport Department has recorded 3 billion passengers taking different kinds of public transport (Train, flights, bus, ferries...) in the whole country, for the whole month of Chinese New Year (2 weeks before and 2 weeks after), for people travelling back home before the festival, during the festival, and going back to the cities where they work.
Out of which, 4 hundred million passengers took the high speed train system. With the train stations in Canton, Shenzhen, Beijing and Shanghai the busiest, as these are the most developed cities in China, which provide most working opportunities for Chinese people in other provinces.
It is expected the the figure will be similar in 2018, with more people travelling on one hand, but change of transport habit on the other, such as people choose to drive back home or use carpool service by Didi Chuxing (The Chinese version of UBER).
Even if you are driving, expect to spend at least 3 times on the road, as there are congestion in all major inter-city highways.
As a foreigner, it is extremely difficult to travel in China during the Chinese New Year period, as tickets are difficult to get, everywhere is crowed, security is tight at stations ..... So if you planning your next business trip to China, do not come during the Chinese New Year period.