A video posted on social media reveals San Francisco police pulling over a self-driving vehicle, only to find nobody inside.
In the video, the hatchback is stopped by police in the city's Richmond District, and the vehicle belongs to an autonomous car company, Cruise, which is based in the Bay Area.
The video starts off with what appears to be a typical police pull-over, as the vehicle had been seen driving without its headlights on.
An officer gets out of a police car that is parked close behind and approaches the Cruise car, finding it empty.
A bystander can be heard saying, "Ain't nobody in it — this is crazy."
The car then proceeds to drive to the other side of the intersection, only to stop again and activate its hazard lights.
Police then approach the car a second time.
The video, which was originally posted on Instagram, has since circulated widely on social media.
A Twitter user, Seth Weintraub, posted the video with a "Welcome to the future" comment.
In a direct response to Weintraub's tweet, Cruise's corporate Twitter account said the vehicle had operated as expected, by driving to a safer location on the other side of the intersection.
Cruise also said they "work closely with the San Francisco Police Department on how to interact with our vehicles, including a dedicated phone number for them to call in situations like this".
As Australia inches closer to endorsing driverless vehicles with on-road trials, the Cruise video has resurfaced questions of vehicle safety and testing.
Meanwhile, other driverless car companies — including Elon Musk's Tesla and Aurora Innovation — are developing their own autonomous vehicle technology.
