A visitor (L) talks to a staff at the 13th International Trade Fair for Infrastructure, Traffic Management, Safety and Parking (ITS Asia 2019) in east China's Shanghai, May 28, 2019. ITS Asia 2019 kicked off at National Exhibition and Convention Center in Shanghai on Tuesday. (Xinhua/Fang Zhe)

Visitors view exhibits at the 13th International Trade Fair for Infrastructure, Traffic Management, Safety and Parking (ITS Asia 2019) in east China's Shanghai, May 28, 2019. ITS Asia 2019 kicked off at National Exhibition and Convention Center in Shanghai on Tuesday. (Xinhua/Fang Zhe)

Visitors view exhibits at the 13th International Trade Fair for Infrastructure, Traffic Management, Safety and Parking (ITS Asia 2019) in east China's Shanghai, May 28, 2019. ITS Asia 2019 kicked off at National Exhibition and Convention Center in Shanghai on Tuesday. (Xinhua/Fang Zhe)

Visitors view exhibits at the 13th International Trade Fair for Infrastructure, Traffic Management, Safety and Parking (ITS Asia 2019) in east China's Shanghai, May 28, 2019. ITS Asia 2019 kicked off at National Exhibition and Convention Center in Shanghai on Tuesday. (Xinhua/Fang Zhe)

Visitors view exhibits at the 13th International Trade Fair for Infrastructure, Traffic Management, Safety and Parking (ITS Asia 2019) in east China's Shanghai, May 28, 2019. ITS Asia 2019 kicked off at National Exhibition and Convention Center in Shanghai on Tuesday. (Xinhua/Fang Zhe)