Power outage paralyzes Waymo robotaxis when traffic lights go out

San Francisco was affected by a massive power outage over the weekend. It started with a fire at a substation in the city on Saturday afternoon, causing a blackout that at times affected as much as a third of the city, leaving more than 130,000 homes without power. Among the city’s affected critical systems were the traffic lights, which paralyzed Waymo’s fleet of robotaxis, stopping them in their tracks and clogging traffic.

Any recent visitor to San Francisco can’t help but notice the profusion of sensor-festooned autonomous vehicles on the roads, especially the all-white Jaguar I-Paces that belong to Waymo. The robotaxi company has more than 800 AVs in its Bay Area fleet; that can feel like a conservative estimate when you see five or six at a time—invariably with no occupants—within a block.

The cars navigate the city, combining high-resolution maps with inputs ...