An unknown technical problem caused a number of robotaxis owned by the Chinese tech giant Baidu to freeze on Tuesday in the middle of traffic, trapping some passengers in the vehicles for more than an hour.In Wuhan, a city in central China where Baidu has deployed hundreds of its Apollo Go self-driving taxis, people on Chinese social media reported witnessing the cars suddenly malfunction and stop operating. Photos and videos shared online show the Baidu cars halted on busy highways, often in th...