Railway technicians examine a railway line manually at the Liupanshui engineering and electricity section of China Railway Chengdu Group in Liupanshui, southwest China's Guizhou Province, Feb. 11, 2019. The Spring Festival travel rush witnessed a surge in passenger flow. Railway technicians, with an increasing workload, worked carefully to secure railways for the Spring Festival travel rush. (Xinhua/Tao Liang)

　　A railway technician examines a railway line manually in a tunnel at the Liupanshui engineering and electricity section of China Railway Chengdu Group in Liupanshui, southwest China's Guizhou Province, Feb. 11, 2019. The Spring Festival travel rush witnessed a surge in passenger flow. Railway technicians, with an increasing workload, worked carefully to secure railways for the Spring Festival travel rush. (Xinhua/Tao Liang)

　　Railway technicians examine railway lines at the Liupanshui engineering and electricity section of China Railway Chengdu Group in Liupanshui, southwest China's Guizhou Province, Feb. 11, 2019. The Spring Festival travel rush witnessed a surge in passenger flow. Railway technicians, with an increasing workload, worked carefully to secure railways for the Spring Festival travel rush. (Xinhua/Tao Liang)

　　Railway technicians examine railway lines at the Liupanshui engineering and electricity section of China Railway Chengdu Group in Liupanshui, southwest China's Guizhou Province, Feb. 11, 2019. The Spring Festival travel rush witnessed a surge in passenger flow. Railway technicians, with an increasing workload, worked carefully to secure railways for the Spring Festival travel rush. (Xinhua/Tao Liang)

　　Railway technicians examine railway lines at the Liupanshui engineering and electricity section of China Railway Chengdu Group in Liupanshui, southwest China's Guizhou Province, Feb. 11, 2019. The Spring Festival travel rush witnessed a surge in passenger flow. Railway technicians, with an increasing workload, worked carefully to secure railways for the Spring Festival travel rush. (Xinhua/Tao Liang)

　　Railway technicians examine a railway line at the Liupanshui engineering and electricity section of China Railway Chengdu Group in Liupanshui, southwest China's Guizhou Province, Feb. 11, 2019. The Spring Festival travel rush witnessed a surge in passenger flow. Railway technicians, with an increasing workload, worked carefully to secure railways for the Spring Festival travel rush. (Xinhua/Tao Liang)