The breakdown of Chinese tech giant Baidu’s autonomous driving vehicles in Wuhan on Tuesday evening affected services and left many passengers stranded on highways with heavy traffic for hours, hurting the company’s autonomous driving ambitions as it moves to expand its robotaxi business globally.

Phone calls for help from affected customers to the traffic police line in Wuhan, capital of central Hubei province, surged from 8.57pm, after many Apollo Go robotaxis stopped in the middle of the road, according to a notice from the city’s transport authority.

Traffic police and staff from Apollo Go, Baidu’s self-driving unit, were dispatched to rescue the trapped riders. No casualties were reported.

Images and videos shared on social media by some Apollo Go riders showed their vehicles stalled on the elevated expressway of Wuhan’s second and third ring roads, clogging traffic and causing several rear-end collisions.

Although the vehicles’ doors could open, heavy peak-hour traffic prevented stranded passengers from safely exiting the expressways – infrastructure designed primarily for vehicles, not pedestrians.

Luka Lu, who works in the live-streaming industry, hailed an Apollo Go vehicle to work at around 8.30pm. Some 15 minutes later, his vehicle abruptly stopped in the middle of the third ring road.