Waymo is deploying a fleet-wide software update after a major power outage in San Francisco revealed a critical limitation in its autonomous driving system. The blackout forced the Alphabet-owned company to temporarily halt robotaxi operations as self-driving vehicles struggled at darkened intersections across the city.
Outage triggers city-wide gridlock
The weekend outage, caused by a fire at a PG&E substation in the South of Market area, knocked out electricity to nearly one-third of San Francisco. Traffic signals went dark across large parts of the city, triggering severe congestion during one of the busiest shopping weekends of the year.
At the peak of the disruption, roughly 30% of the city were without power, with traffic lights failing from downtown to the Richmond and Presidio neighborhoods.
Robotaxis stall at dark intersections
Waymo vehicles are designed to treat dark signals as four-way stops, but the scale of the outage overwhelmed the company’s remote human assistance system. Multiple vehicles remained stationary at intersections and along major corridors, contributing to congestion as police and fire crews were deployed to manually direct traffic.
Videos shared on social media showed several Waymo robotaxis immobilized in busy areas as the blackout intensified.
Service paused as disruption deepens
Waymo said it proactively paused operations on Saturday evening as conditions worsened, with non-functioning traffic signals and transit disruptions clogging city streets. Vehicles were either returned to depots or pulled safely to the side of the road to avoid obstructing emergency responders.
The company worked closely with San Francisco officials throughout the outage, coordinating vehicle movements while crews worked to restore power and manage traffic.
Fleet-wide software fix underway
In response, Waymo is rolling out a software update aimed at helping its autonomous system better recognize large-scale power outagesThe update is designed to allow vehicles to navigate dark intersections more decisively without overloading the remote assistance system during widespread infrastructure failures,
Expansion continues despite setback
Waymo is a leading commercial robotaxi operator in the US, running driverless services in five major cities. Its fleet of more than 1,500 vehicles operates in markets including Phoenix, Los Angeles, Austin and Atlanta, with plans to expand to more than two dozen additional cities by the end of 2026.
