Streets in Wuhan, Hubei Province, where 11 million people have forced to stay indoors since January, were suddenly clogged with traffic as thousands streamed out of the city to return to homes and jobs elsewhere.
Yellow barriers that had blocked off some streets were gone, although gates to residential compounds remained guarded.
Nearly 1,000 vehicles went through a busy highway toll booth at Wuhan's border between midnight, when barricades were lifted, and 7am, according to Yan Xiangsheng, a district police chief.
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Wuhan residents are now permitted to leave without special authorisation as long as a mandatory smartphone application powered by a mix of data-tracking and government surveillance shows they are healthy and have not been in recent contact with anyone confirmed to have coronavirus.
Schools are still closed, temperatures are checked when people enter buildings, and masks are strongly encouraged.
The Chinese government reported no new cases of coronavirus in the city on Wednesday – however, there are questions about the veracity of China's count.