|The annual new year holiday sees millions on the move across China [EPA]
Millions of Chinese travellers have crowded into airports, train terminals and bus stations as the annual Lunar New Year holiday travel season reaches its peak.
The Lunar New Year, or Spring Festival, which falls on Sunday is China's most important holiday.
For many, particularly China's millions of migrant workers, it is the only holiday of the year and the only opportunity to return home to see their families.
Al Jazeera's Tony Birtley reports on the exodus from a train heading south from Beijing
The annual travel exodus from China's cities is believed to be the world's largest annual human migration.
More than 210 million people were expected to crowd China's railways during the New Year period, which officially began in late January, as officials scramble to accommodate what are projected to be record passenger numbers.
For many travellers the journey home will take several days.
The government has said more than 650 million "passenger trips" had been taken as of Tuesday.
The holiday also proves to be annual headache for Chinese authorities as the crush of people typically chaos on an overburdened transport network and travellers desperately try to secure tickets amid reports of price-gouging.
On Friday, the government warned that rain and snow storms would hit the north of the country this weekend, threatening to disrupt the travel plans of anyone who had left their journey's until the last minute.
|Many travellers face long and uncomfortable journeys with little space [Reuters]
In early 2008, an unprecedented cold wave across southern and central China marked by freezing rains crippled transport systems just as the travel rush got under way, stranding millions.
But authorities have taken a number of steps to maintain order including deploying thousands of additional transport police, particularly in provinces such as southern Guangdong, an export factory hub that employs tens of millions of migrants.
So far, few major disruptions have been reported.
China has an estimated 150 million or more migrants mainly from interior rural areas working in big cities or other industrial areas on the coast.
Their remittances, as well as cash and goods they bring home at the holidays, are a vital lifeline to their families.
Source: Al Jazeera and agencies