Massive outage left driverless cars stuck at intersections, reigniting questions about AV readiness during real-world chaos.
Blackout Brings Robotaxis to a Halt
A major power outage in San Francisco on Saturday evening caused a citywide traffic jam—and Waymo’s robotaxi fleet was caught in the middle. Videos across social media showed driverless vehicles stalled at intersections, blocking roads and confusing human drivers.
The blackout, caused by a fire at a PG&E substation, left over 120,000 customers without power, including many of the city’s traffic signals and public transit systems. San Francisco Mayor Daniel Lurie advised residents to stay off the roads entirely.
Waymo responded by suspending robotaxi service citywide. The company resumed operations late Sunday afternoon, stating that it is “rapidly integrating the lessons learned” from the event.
What Went Wrong?
Waymo’s self-driving system is designed to handle non-functioning traffic lights by treating them as four-way stops—a standard rule for AVs and human drivers alike. But this event revealed an edge case at scale:
“The scale of Saturday’s blackout caused some vehicles to remain stationary for longer than normal as they tried to assess the intersections,” Waymo told TechCrunch.
- Human drivers were forced to maneuver around the robotaxis.
- While most Waymo trips were reportedly completed successfully, some vehicles froze, causing localized traffic jams.
It wasn’t the AV system crashing—it was the system hesitating in uncertainty.
A Stress Test for Autonomy
The incident reignites a core question for AVs: How well can they operate in chaotic, unpredictable conditions?
“Grid-scale blackouts are rare, but they expose real-time limitations in autonomous logic,” said a Bay Area mobility analyst.
Even if traffic lights are down, human drivers tend to read social cues, wave others through, or react to subtle gestures—skills still outside the scope of AV software.
The event also illustrates how AV behavior at scale matters more than isolated performance. If even 5% of robotaxis stall during a disaster, that’s enough to create widespread gridlock.
Service Resumes, But So Do Concerns
Waymo emphasized that it is working quickly to update its systems to handle large-scale outages more fluidly. “We are committed to ensuring our technology adjusts to traffic flow during such events,” the company said.
The update follows a leaked investor letter from Tiger Global earlier this month revealing that Waymo is now delivering 450,000 robotaxi rides per week—double the volume reported earlier this year.
- That surge underscores how embedded Waymo has become in urban mobility.
- But the blackout also shows how even a handful of failed interactions can erode public trust, a critical ingredient for AV adoption.
“This wasn’t a bug. It was a preview of what happens when autonomy meets emergency.”
What’s Next for Waymo and the AV Industry?
While this may go down as a minor glitch in Waymo’s trajectory, it’s a major signal for regulators, engineers, and city planners.
- Expect calls for stress-testing AVs under edge conditions—blackouts, wildfires, flash floods.
- Municipalities may need coordinated AV disaster protocols, just as they have for human-driven fleets.
Waymo, for its part, says it remains committed to earning community trust and learning from every incident. But as the AV footprint expands, so too will the complexity of real-world variables it must master.
