Waymo to update software after San Francisco power outage

In a company blog post, Waymo said, “This past Saturday, as a widespread PG&E outage cut power to nearly one-third of San Francisco, our service was put to the test. With power now restored, we want to share an account of our operations during the outage and how we are evolving to better serve the city. The scale of the outage and the sheer number of disabled traffic lights were the primary contributors to city-wide gridlock. As signals went dark across major corridors, the resulting congestion required law enforcement to manually manage intersections. The situation was severe enough that the San Francisco Department of Emergency Management advised residents to stay home, underscoring the extraordinary nature of the weekend’s disruptions. Navigating an event of this magnitude presented a unique challenge for autonomous technology. While the Waymo Driver is designed to handle dark traffic signals as four-way stops, it may occasionally request a confirmation check to ensure it makes the safest choice. While we successfully traversed more than 7,000 dark signals on Saturday, the outage created a concentrated spike in these requests. This created a backlog that, in some cases, led to response delays contributing to congestion on already-overwhelmed streets. We established these confirmation protocols out of an abundance of caution during our early deployment, and we are now refining them to match our current scale. 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.”