Passengers wait to get on a train in Nanjing Railway Station, Jiangsu province, on February 11, 2015. [Photo/IC]

The 2015 Spring Festival travel rush, also known as Chunyun in Chinese, is already underway as hundreds of millions of those working or studying away from their hometowns hurry home. Meanwhile, railway workers, police, train attendants and volunteers also gear up for the world's largest human migration.