A waitress serves on train No. K497 from Beijing to northeast China's Heilongjiang Province, Jan. 20, 2019. Hundreds of millions of Chinese return to their hometowns every year for the Lunar New Year, or Spring Festival, family reunions, thus forming the Spring Festival travel rush. The 2019 travel rush started on Jan. 21, with 3 billion trips expected to be made. (Xinhua/Cai Yang)