GONGXIAN, CHINA: Pushingthrough scores of passengers in theaisle of a cramped train at BeijingWest station, Chen Guolan couldbarely contain her excitement atjoining the world’s largest annualhuman migration.”I have been so busy working awayall year, and now I will soon be seeingmy family,” she said to a group ofstrangers sitting alongside her as shebegan an epic 2,000 kilometre journeyback to the quiet backwater she callshome.

Chen is one of China’shundreds of millions of migrantworkers, who together make most ofthe 220 million train rides takenduring the 40-day travel season beforeand after the Lunar New Year.Around 7:30am she left the high-riseapartment where she works as adomestic worker for a family of sevenin the capital, a city of more than 20million people enduring sub-zeroFebruary temperatures and heavilypolluted air. Within 48 hours shewould be beside her husband and sonin the family home in a quiet, ruggedarea of the warmer south-westernprovince of Sichuan, where the treecappedmountains are hugged by mist,rather than toxic haze.

Chen hadbought her 229 yuan ($37) ticket forthe 10.35am to Chongqing two weeksearlier, joining millions who haveclogged internet travel sites andqueued at train stations to ensure theywill be home for China’s mainnational holiday. Demand isphenomenal. For China’s 236 millionmigrant workers, it is the only time ofyear they can see their families.