Waymo has resumed its autonomous ride-hailing service in San Francisco following a temporary shutdown triggered by a widespread power outage that disrupted traffic across the city.

The Alphabet-owned company paused operations on Saturday evening after a major blackout left several robotaxis immobilized on roads and at intersections. Images and videos shared on social media showed Waymo vehicles stopped in traffic, forcing human drivers to maneuver around them.

In a statement released late Sunday, a Waymo spokesperson confirmed that services were gradually restored after the situation stabilized. According to the company, the outage caused extensive gridlock, largely due to malfunctioning traffic signals and interruptions to public transportation.

“The power failure was a large-scale incident that affected traffic flow throughout San Francisco,” the spokesperson said. “Despite the significant impact of the utility outage, we remain committed to ensuring our technology can adapt effectively during such disruptions.”

Waymo noted that while its autonomous systems are programmed to treat non-operational traffic lights as four-way stops, the unusual scale of the blackout led some vehicles to pause longer than usual as they assessed complex intersections. The company emphasized, however, that most active trips were completed successfully despite the challenges.

The outage also affected San Francisco’s Muni transit system and disabled numerous traffic lights, prompting Mayor Daniel Lurie to advise residents to avoid traveling unless necessary. Reports indicate the blackout was caused by a fire at a Pacific Gas & Electric substation, impacting approximately 120,000 customers. Although power was restored to many by late Saturday, tens of thousands remained without electricity into Sunday morning.

Waymo said it is now reviewing the incident to improve its response to similar events in the future, stressing its commitment to safety and public trust. The company added that lessons learned from the disruption are being rapidly integrated into its operations.

The service disruption comes as Waymo continues to scale its robotaxi business. A recently leaked letter from Tiger Global Management revealed that the company is now providing about 450,000 autonomous rides per week—nearly double the figure disclosed earlier this year.

Waymo confirmed that normal operations have now resumed across San Francisco.

Source: Techcrunch