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 the fast lane. A college student in Wuhan tells WIRED that she was stuck in a Baidu robotaxi with two friends for about 90 minutes on Tuesday. (She asked to be only identified with her last name, He, to protect her privacy.) The student says the car malfunctioned and stopped four or five times during the trip before it eventually parked in front of an intersection in eastern Wuhan. Luckily, it was not a busy road, and the group was not in immediate danger.…