Waymo’s robotaxis freeze up in SF blackout

A five-story power substation fire triggered a massive blackout in San Francisco on Saturday, cutting electricity to roughly 130,000 customers. But on the roads, an even stranger scene unfolded: scores of Waymo robotaxis simply froze in place, paralyzing intersections across the city.

With social media flooded with videos of human drivers aggressively weaving around stranded autonomous SUVs, Waymo pulled the plug and temporarily suspended its ride-hailing operations. The Alphabet-backed service finally restarted late Sunday afternoon.

The network bottleneck behind the freeze

Electric cars do not stop rolling just because utility lines go down, so what went wrong?

Waymo explained that its driverless system is programmed to treat unpowered traffic lights as four-way stops. But with Muni transit offline and San Francisco Mayor Daniel Lurie advising residents to stay off the streets, the chaos overwhelmed the fleet's decision-making.

The real culprit, however, appears to be the wireless data network. As cell towers lost power and offline residents jammed mobile bandwidth, the robotaxis likely lost touch with base camp.

When a Waymo encounters an edge case it cannot solve, it beams live camera footage and 3D sensor maps to remote human operators for navigation assistance. Without adequate cellular bandwidth, the cars do what they are programmed to do in a total blind spot: brake and refuse to move until a human answers.

Elon Musk quickly jumped on X to claim that Tesla Robotaxis were unaffected by the blackout, while videos circulated of drivers using Tesla FSD to navigate the darkened streets.

Why it matters

Waymo has been scaling at breakneck speed. A leaked Tiger Global letter revealed earlier this month that the company now serves 450,000 trips per week, roughly doubling its volume from the spring.

Yet this blackout exposes a fragile design premise. Waymo’s safety posture leans heavily on high-bandwidth infrastructure and remote tele-operators acting as invisible safety nets.

We think playing it ultra-safe by coming to a complete stop makes sense inside an engineering room. But in a real-world municipal crisis, dozens of paralyzed two-ton vehicles blocking emergency personnel quickly become hazards themselves.

For riders, it is a reminder that driverless tech is not yet disaster-proof. For the industry, this incident will force Waymo to rethink offline autonomy. If your self-driving vehicle turns into a brick whenever cellular towers congest, it is not truly autonomous yet.