When large parts of San Francisco went dark during a mass power outage, the city got an unscripted stress test of its driverless future. Waymo’s robotaxis stalled at intersections and turned into obstacles, while Teslas with driver-assist features kept threading through the chaos, exposing a sharp contrast in how the two companies design for the edge cases that rarely show up in glossy demos. The blackout did not just snarl traffic, it raised uncomfortable questions about whether today’s most advanced robotaxis are ready for the messy, failure-prone infrastructure of real cities.
At stake is more than bragging rights in Silicon Valley. Waymo has pitched its fully driverless service as a safer, more reliable alternative to human drivers, and Tesla has promised a vast robotaxi network built on the cars it already sells. The blackout episode, and the way both companies responded, offers an unusually clear look at the strengths and weak spots of each strategy just as regulators, investors, and riders are deciding how much to trust software with the steering wheel.
When San Francisco went dark, the Waymos stopped moving
The outage that plunged San Francisco into gridlock started with a fire at a substation that cut power to more than 100,000 homes and businesses and knocked out traffic signals across key corridors. With mass outages for traffic lights, Waymo’s self-driving taxis began shutting down, stopping at intersections and refusing to proceed without the digital cues they normally rely on. Social media posts captured the surreal scene of driverless vehicles frozen in place while lines of human-driven cars stacked up behind them, turning already stressed streets into a maze of stalled metal.
Reports from the city described Waymo robotaxis effectively becoming roadblocks, immobilized in the middle of junctions and unable to improvise their way through the blackout. The mass power outages blacked out large parts of San Francisco and, instead of smoothing traffic, the autonomous fleet amplified the disruption by occupying critical lanes that human drivers might otherwise have used to inch through darkened intersections. The result was a vivid demonstration that a system tuned for orderly, signalized streets can falter when the underlying infrastructure fails at scale.
Inside the navigation gap that froze Waymo’s fleet
What failed inside the vehicles was not the hardware but the logic that tells the Waymo Driver how to behave when its usual reference points disappear. During the blackout, the cars lost key navigation capability, struggling to reconcile missing traffic signals, degraded connectivity, and conflicting sensor inputs about who had the right of way. According to technical accounts of the incident, the software defaulted to conservative behavior, which in practice meant stopping and waiting indefinitely rather than attempting to negotiate ambiguous intersections without clear digital guidance…