Waymo is rolling out a fleet-wide software update after a massive San Francisco power outage exposed a critical bottleneck in its autonomous system — forcing the Alphabet-owned company to halt robotaxi service as driverless cars stalled at darkened intersections across the city.
The update is designed to help Waymo’s self-driving software better recognize and respond to large-scale power outages, allowing vehicles to move through dark intersections more decisively without overwhelming the company’s remote human assistance system, which got bogged down during the blackout.
The fix follows a weekend outage that knocked out electricity for nearly a third of San Francisco and disabled traffic signals citywide, triggering gridlock and leaving multiple Waymo vehicles stopped or stationary in the middle of busy streets.
The blackout, sparked by a fire at a PG&E substation in the South of Market neighborhood, knocked out traffic signals across large swaths of the city on Saturday afternoon, creating gridlock that exposed limits in Waymo’s autonomous system as multiple vehicles stopped or remained stationary in the middle of busy streets.
Waymo said it proactively paused operations Saturday evening as the outage intensified, with nonfunctioning traffic lights and transit disruptions overwhelming city streets during one of the busiest shopping weekends of the year.
Videos shared on social media showed multiple Waymo vehicles immobilized at intersections and along major corridors as power failed citywide, adding to congestion as police and fire crews were deployed to manually manage traffic in affected neighborhoods.
At the height of the outage, as many as 130,000 households — about 30% of the city — lost electricity, knocking out signals from downtown to the Richmond and Presidio and causing Waymo vehicles to stop at intersections just ahead of peak evening traffic.
The company said it worked with San Francisco officials throughout the blackout, returning vehicles to depots or pulling them safely to the side of the road as emergency crews worked to restore order on streets where traffic lights were completely dark.
Waymo resumed service Sunday evening after power was restored to most neighborhoods, though thousands of customers remained without electricity and PG&E crews continued repairs into Monday following what the utility described as “significant and extensive” damage at the substation.
Waymo said its vehicles are designed to treat dark signals as four-way stops, but acknowledged that the scale of the outage led to cars remaining stationary longer than usual as they attempted to confirm intersection conditions amid widespread signal failures.
The pause marked one of the most visible disruptions yet for Waymo in its home market, where the company operates fully driverless ride-hailing at scale and has pitched its technology as capable of handling complex urban conditions without human intervention.
Waymo has emerged as the leading commercial robotaxi operator in the US, running fully driverless ride-hailing services in five major cities and logging more than 100 million autonomous miles and over 14 million paid rides as of late 2025.
Its fleet of more than 1,500 vehicles operates at scale in markets including Phoenix, Los Angeles, Austin and Atlanta, as the company pushes an aggressive expansion plan targeting more than two dozen additional cities by the end of 2026.
Despite publishing data showing sharply lower crash rates than human drivers, Waymo has faced mounting scrutiny following a series of high-profile incidents, particularly in San Francisco.
Those include collisions with cyclists and vehicles, animal fatalities, software-related traffic violations and disruptions tied to infrastructure failures.
The latest San Fran incident has intensified concerns among residents and some lawmakers about how autonomous vehicles handle rare but predictable “edge cases,” such as large-scale power outages.
Critics argue those scenarios expose limitations in current technology even as Waymo seeks rapid growth.
The company has said it is reviewing lessons from the outage while continuing to scale its driverless service nationwide.
“We resumed ride-hailing service in the San Francisco Bay Area on Sunday,” a Waymo spokesperson told The Post.
“Saturday’s power outage was a widespread event that caused gridlock across San Francisco, with non-functioning traffic signals and transit disruptions. While the failure of the utility infrastructure was significant, we are committed to ensuring our technology adjusts to traffic flow during such events.”
The spokesperson added that “throughout the outage, we closely coordinated with San Francisco city officials.”
“We are focused on rapidly integrating the lessons learned from this event, and are committed to earning and maintaining the trust of the communities we serve every day.”
