- Waymo paused service after a blackout disrupted traffic citywide.
- Robotaxis were stalled for hours at dark San Francisco junctions.
- Incident exposed a major weakness in autonomous vehicle logic.
Waymo has become the undisputed frontrunner in America’s robotaxi race, thanks to a wide-scale rollout and a relatively consistent safety record. But being first doesn’t always mean flawless. Despite the progress, the company’s autonomous network still struggles with scenarios that human drivers routinely navigate without hesitation.
The latest example came during a widespread power outage in San Francisco, which exposed a critical vulnerability in the system, highlighting the most worrisome problem to date.
What Happens When the Lights Go Out?
Power went out Saturday afternoon following a fire at a Pacific Gas and Electric substation, knocking out power to as many as 130,000 customers at its peak. Traffic signals went dark, public transit was disrupted, and congestion spread quickly across affected neighborhoods.
That’s where the Waymo units began to have major problems.
Videos shared on social media appeared to show multiple autonomous taxis stopped in traffic for extended periods, including one photographed on Turk Boulevard near Parker Avenue.
More: People Tricked Waymo’s AI Sending 50 Robotaxis To A Dead-End Street
San Francisco resident Matt Schoolfield told CNBC that he saw at least three Waymo vehicles stalled between 6 p.m. and nearly 10 p.m., describing them as “just stopping in the middle of the street.”
System Overload and Standstill
Waymo spokesperson Suzanne Philion confirmed the issue, stating that the outage overwhelmed the company’s software logic. While the cars are programmed to handle non-functioning traffic signals as four-way stops, the scale of the blackout pushed them beyond their limits.
According to Waymo, the scale of the blackout caused vehicles to remain stationary longer than expected while attempting to confirm intersection status, contributing to congestion during peak gridlock.
The company paused service Saturday evening and into Sunday, coordinating with city officials and safely returning vehicles to depots or pulling them over. This failure on the part of Waymo became an opportunity for Tesla CEO Elon Musk to point out that his brand’s robotaxis had no issue during the blackout.
“Tesla Robotaxis were unaffected by the SF power outage,” said Musk in response to a video highlighting the Waymo struggle. That claim comes with an important caveat. Tesla does not operate a fully driverless robotaxi service in San Francisco. Its local ride-hailing efforts rely on vehicles running “FSD (Supervised),” which still require a human driver behind the wheel at all times.