Waymo to Update Software Across Fleet After San Francisco Power Outage

By Kimberley Kao

Alphabet's Waymo said it will update its software across the fleet to navigate outages better, after its self-driving vehicles froze and caused traffic congestion during a widespread power outage in San Francisco last weekend.

Waymo, the self-driving car startup owned by Google parent Alphabet, plans to roll out fleet-wide updates, expand its first responder engagement and update its emergency response protocol, it said in a statement Tuesday.

The outage on Dec. 20, which cut power to nearly one-third of the city, was caused by a fire at Pacific Gas and Electric Company's substation, according to the power company.

"The scale of the outage and the sheer number of disabled traffic lights were the primary contributors to city-wide gridlock," Waymo said.

While Waymo's driver system already handles dark traffic signals as four-way stops, it will occasionally request confirmation checks to ensure it is the "safest choice." The outage created a "concentrated spike" in requests, creating a backlog and response delays, Waymo said. Still, its vehicles had "successfully" handled over 7,000 dark traffic signals, it said.

"We established these confirmation protocols out of an abundance of caution during our early deployment," it said. "While this strategy was effective during smaller outages, we are now implementing fleet-wide updates that provide the Driver with specific power outage context, allowing it to navigate more decisively," it added.

Write to Kimberley Kao at kimberley.kao@wsj.com

(END) Dow Jones Newswires

December 23, 2025 23:09 ET (04:09 GMT)