Self-driving cars from GM’s Cruise are taking over the streets of San Francisco

Auto and tech industry executives have long promised that autonomous vehicles would drive better than humans, but that wasn’t the case with a fleet of cruise cars in San Francisco this week.

A company that is a majority-owned subsidiary General Motors Company, confirmed that earlier this week there was “an issue that caused some of our cars to group together.” A company spokesman said the problem had been “resolved and no passengers were injured”, but declined to provide further details.

Photos and description of a cruising robotaxi blocking several lanes of traffic in San Francisco have been released on reddit and Twitter. At least seven cruisers could be seen late Tuesday night at the intersection of Gough and Fulton streets in the Civic Center neighborhood, potentially blocking traffic in both directions on one of the streets.

It is not clear how long the cars have been blocking the roads or what caused the situation with the vehicles operating without people other than paying customers.

This incident is another example of how difficult it is to develop and deploy fleets of self-driving cars. Commercializing autonomous vehicles has been much more difficult than many predicted just a few years ago. The challenges have led to consolidation in the self-driving car sector after years of enthusiasm touting the technology as the next a multi-trillion dollar market for transport companies.

The San Francisco Department of Emergency Management was notified and contacted Cruz about the problem, San Francisco Police Department Public Information Officer Kathryn Winters told CNBC. She said officers were not dispatched to the scene.

The incident comes about a week after Cruise became the first company to offer unmanned rides to the public in a major city. Transport operates from 22.00 to 6.00 on certain streets.

Alphabet-backed Waymo has reportedly faced similar challenges with its autonomous vehicle cluster in San Francisco. KPIX-TV, the CBS affiliate in San Francisco, reported in October that Waymo cars are stuck in gridlock in the city.

Cruz’s issue also comes months after an online video of the self-driving car the car was stopped by the police without anyone driving. In the video, released on April 1, the Cruise vehicle first pulls to the side of the road and stops as the officer approaches the driver before accelerating to cross the intersection and drive further down the road.