Staff members clean train carriages at a service garage in Hengyang, central China's Hunan Province, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Photo by Cao Zhengping/Xinhua)

Aerial photo taken on Jan. 16, 2022 shows staff members cleaning train carriages at a service garage in Hengyang, central China's Hunan Province. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Photo by Cao Zhengping/Xinhua)

Crew members prepare epidemic prevention kits on train G1724 in east China's Shanghai, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Chen Fei)

A crew member distributes epidemic prevention pamphlets on train G1724 in east China's Shanghai, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Chen Fei)

Crew members place disinfection notices on train G1724 in east China's Shanghai, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Chen Fei)

Crew members guide a passenger to board train G1724 at Shanghai Hongqiao Railway Station in east China's Shanghai, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Chen Fei)

Staff members make hand heart gestures at Xi'an North Railway Station in Xi'an, northwest China's Shaanxi Province, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Tao Ming)

A staff member works at Xi'an North Railway Station in Xi'an, northwest China's Shaanxi Province, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Tao Ming)

Staff members spray disinfectants on the platform of Xi'an North Railway Station in Xi'an, northwest China's Shaanxi Province, Jan. 16, 2022. The Spring Festival travel rush, China's largest annual travel rush, will last from Jan. 17 to Feb. 25 this year. During the 40-day travel season, also known as chunyun, many Chinese people will travel to meet their families for the Chinese Lunar New Year, or Spring Festival, which will fall on Feb. 1, 2022. (Xinhua/Tao Ming)