When the power went out in San Francisco over the weekend, experts say Waymo robotaxis failed a major stress test.
Images of Waymo vehicles stopped in roads and intersections — backing up traffic across the city — raised immediate questions about how the robotaxis would behave during a disaster, and whether similar failures could block emergency responders or residents fleeing danger.
Those concerns extend south to San Jose, where Waymo recently expanded service along the Peninsula, including on freeways and trips to Mineta San Jose International Airport.
“Waymo should have seen this coming — there’s no excuse,” said Philip Koopman, a professor emeritus at Carnegie Mellon University who studies robotaxi technology. “We just had what amounts to a dress rehearsal for an earthquake and Waymo failed the test. Thank goodness this was not an earthquake.”
Since Waymo robotaxis debuted in San Francisco in 2023,the rollout has been marked by repeated problems, including vehicles freezing in traffic and blocking fire trucks and police responding to emergency scenes. Other incidents have included failures to stop for school buses — prompting a federal investigation — and the death of a beloved San Francisco convenience store cat. Now, questions about how the vehicles function during a power outage have been added to the list.
“It’s a huge concern,” said California state Sen. Dave Cortese, who represents much of Santa Clara County and chafes at local officials’ inability to regulate robotaxis. The vehicles are regulated by the California Department of Motor Vehicles and the California Public Utilities Commission.
“They’ve given us the impression, they’ve given the DMV the impression, that they’re road-ready, that they’re smarter than human drivers,” Cortese said. “It seems like they’re not. They’re really using the roads experimentally.”
Such a shutdown “is likely to happen in San Jose and a number of other places in the future,” Cortese predicted.
Scenes from Saturday — robot cars stalled in busy thoroughfares with hazard lights flashing as motorists honked in frustration — marked the broadest-scale malfunction of the technology since the earliest stages of its rollout.
The cars “should be able to do as well as a competent human driver,” said Koopman, the researcher who studies robotaxis, “and they clearly did not do that.”
Waymo did not respond to detailed questions about what caused the shutdown, how the company responded, or what it will do to ensure it does not happen again. The company resumed robotaxi operations in San Francisco on Sunday, CNBC reported.
Koopman said he believes the Waymo cars were overwhelmed by a combination of nonfunctioning traffic lights and other drivers’ responses to the absence of signals, resulting from a fire at a PG&E substation.
Typically, Waymo responds to on-road glitches by having human operators in a remote assistance center take control of vehicles, Koopman said. In this case, either the center was not activated or staff were unable to respond quickly enough — suggesting understaffing or a communications failure.
During an earthquake, Koopman said, Waymo could face even greater challenges ramping up remote staffing while also dealing with potential breakdowns in the cellular networks used to control vehicles remotely. If communications remain intact, operators should move robotaxis to safe locations out of traffic. If communications fail, the vehicles should be programmed to do so on their own.
“If you can get 95% of the Waymos off the road, now you don’t have a paralyzed city,” Koopman said. “As opposed to letting them run until they get stuck, because it’s guaranteed they’ll get stuck.”
Koopman said Waymo should be required to run earthquake-response simulations observed by officials from major cities, including San Jose and San Francisco.
What happened to passengers inside the stalled vehicles was not immediately clear. Koopman said he does not believe Waymo traps riders inside shut-down robotaxis.
The city of San Jose, where Mayor Matt Mahan has welcomed Waymo, and the city of San Francisco referred questions to the company. The California Public Utilities Commission said it was aware of the incident but declined to answer detailed questions. The DMV did not initially respond, but on Tuesday said it had met Monday morning with Waymo to discuss its stopped services, and contacted San Francisco officials about the incident.
“The DMV will continue communication with Waymo to discuss broader operational plans, including actions related to emergency response,” the department said.
Labor advocates say the episode highlights a lack of accountability for autonomous vehicles.
The California Gig Workers Union, which represents Uber and Lyft drivers whose livelihoods are threatened by automated taxis, said human drivers face consequences when they make mistakes. Waymo’s operating permits should be suspended “until they can prove, without question, that they won’t put drivers, passengers, pedestrians, or first responders in harm’s way,” said Joseph Augusto, a San Francisco Uber driver and union member.
