Waymos froze, blocked traffic during San Francisco power outage

Waymo’s driverless ride services were a high-profile victim of a power outage that affected large swaths of San Francisco, with cars freezing mid-ride across the city and disrupting traffic.

After traffic lights went dark at major intersections Saturday, social media videos showed multiple cars stopped in the middle of the street with their hazard lights flashing.

The power failures, which at one point affected 130,000 customers, closed stores and disrupted transit during the busy holiday shopping period — including many Waymo cars, Alphabet Inc.’s self-driving taxi service. 

Michele Riva, 30, was going home Saturday evening in a Waymo car when the outage happened. His car had kept moving when they were in a less transited area of the city, even with passengers crossing on the street, he said. He was only a minute away from his destination when the car stopped in front of a “very dense intersection” and non-working traffic lights, he said, without giving him any notice.

“I stayed in the Waymo for a couple of minutes, just to see,” said Riva, who is an engineer working in artificial intelligence. “The problem was that, at the beginning, there were a lot of people crossing the streets because there were no traffic lights. So I believe the Waymo just didn’t know what to do.”

PG&E Corp., which blamed the outage on a fire in a substation, began restoring mos...