Passengers prepare to board a train at Hongqiao Railway Station in east China's Shanghai, Jan. 10, 2020. China, the world's most populated country, on Friday ushered in its largest annual migration, 15 days ahead of the Spring Festival, or the Lunar New Year. There will be three billion trips during the travel rush from Jan. 10 to Feb. 18 for family reunions and travel, slightly up from that of last year, according to a forecast from the National Development and Reform Commission (NDRC). (Xinhua/Chen Fei)