A widespread power outage in San Francisco over the weekend halted dozens of driverless Waymo vehicles at busy intersections. The utility failure was turned into a stress test for autonomous ride services, re-opening the debate about how prepared the technology is for large-scale urban disruptions.
Tesla’s Elon Musk was quick to respond to how unaffected the Robotaxi fleet remained, but faces its own underwhelming performance in Austin.
The Waymo vehicles weren’t affected directly. When electricity failed across large parts of the city after a substation fire, traffic lights went dark and public transport got disrupted.
Waymo’s autonomous taxis, a familiar sight on San Francisco streets, began stopping mid-block and at intersections, often remaining stationary with hazard lights flashing. Online videos showed drivers maneuvering around the stalled vehicles as congestion built during peak hours.
Police to manage traffic
The outage affected roughly 130,000 customers, according to the utility provider PG&E, and forced city officials to deploy police and emergency crews to manage traffic. Waymo paused its Bay Area ride-hailing operations later that evening, resuming service the following day as power was gradually restored. The company said most trips underway were completed before vehicles were pulled over or returned to depots.
Waymo said its vehicles are programmed to treat dark traffic signals as four-way stops. They still proceed under the American habit that the first-arriving car at the junction has priority to cross, but this procedure takes much longer.
The scale of the outage, combined with communications issues, led some vehicles to wait longer than usual before moving on. That caution, while consistent with the company’s safety-first posture, added to already jammed streets and drew frustration from residents caught behind the waiting cars.
Conservative behavior is preferable
The incident underscores the issue facing autonomous driving systems: their dependence on surrounding infrastructure and connectivity in dense cities.
While Waymo argues that conservative behavior is preferable to risky maneuvers, the sight of multiple vehicles freezing simultaneously raised doubts about how such fleets would perform during earthquakes, storms, or other significant calamities. One can ask how calmly and organised a regular driver would react in such mayhem.
The episode also sparked commentary from Tesla CEO Elon Musk. On his own social media network X, he rapidly claimed that Tesla robotaxis were unaffected by the blackout, which is logical, as a backup driver still governs his fleet in the area.
But Musk is most likely referring to a technological difference. He has long promoted Tesla’s camera-based approach as more flexible than sensor-heavy self-driving. He points to the greater ability to operate without reliance on mapped environments or surrounding infrastructure.
Less than five
That criticism, however, was poorly timed, as it contrasts sharply with Tesla’s current state of its robotaxi effort. In Austin, where Tesla is running a pilot service, user reports suggest the fleet is far smaller and less available than Musk has publicly claimed. This assumption was confirmed by data collected by a university engineering student.
He pointed out that only a handful of vehicles, sometimes as few as five, are operating at any given time. Apparently, the service is frequently unavailable despite official launch announcements. Also in Austin, Tesla’s self-driving vehicles still require onboard supervision, limiting their scalability.
Waymo has since restored full service in San Francisco and says it is reviewing lessons from the outage. As robotaxi operators race to expand, the blackout offered an unscripted but interesting glimpse into how autonomous fleets cope when the city around them stops working.
