Passengers queue to board a train at Zhengzhou East Railway Station in Zhengzhou, central China's Henan Province, May 4, 2019. Zhengzhou railway system witnesses a travel rush as the Labor Day holiday comes to an end. (Xinhua/Feng Dapeng)

Passengers go through ticket gates at Zhengzhou East Railway Station in Zhengzhou, central China's Henan Province, May 4, 2019. Zhengzhou railway system witnesses a travel rush as the Labor Day holiday comes to an end. (Xinhua/Feng Dapeng)

Passengers wait to board a train at Zhengzhou East Railway Station in Zhengzhou, central China's Henan Province, May 4, 2019. Zhengzhou railway system witnesses a travel rush as the Labor Day holiday comes to an end. (Xinhua/Feng Dapeng)

Passengers go through ticket gates at Zhengzhou East Railway Station in Zhengzhou, central China's Henan Province, May 4, 2019. Zhengzhou railway system witnesses a travel rush as the Labor Day holiday comes to an end. (Xinhua/Feng Dapeng)