At Waymo, our mission is to be the world’s most trusted driver. We know that trust is built through consistent behavior over time, earned with every mile traveled and every interaction we have with the community. Last Saturday, as a widespread PG&E outage knocked out power to nearly a third of the city 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 large number of disabled traffic lights were the main factors contributing to the citywide traffic jam. As signals went dark on major corridors, the resulting congestion forced law enforcement to manually manage intersections. The situation was serious 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. Although the Waymo Driver is designed to handle dark traffic lights like four-way stops, it may occasionally ask for a confirmation check to make sure it’s making the safest choice. While we successfully crossed over 7,000 dark signals on Saturday, the outage created a concentrated spike in these requests. This created a delay that in some cases led to response delays, contributing to congestion on already congested streets.
We established these confirmation protocols very carefully during our first deployment, and we are currently refining them to fit our current scale. While this strategy has been effective during minor outages, we are now implementing fleet-wide updates that provide the driver with specific context in the event of a power outage, allowing them to navigate more decisively.
As the outage persisted and municipal officials urged residents to stay off the streets to give priority to first responders, we temporarily suspended our service to the area. We have asked our fleet to stop and park appropriately so that we can return vehicles to our depots in waves. This helped ensure that we will not have further worsened congestion or obstructed emergency vehicles at the height of the recovery effort.
The way forward
We’ve always been focused on developing the Waymo driver for the world as it is, including infrastructure failures. We are analyzing the event and already incorporating lessons from this weekend’s PG&E outage. Here are some of the immediate steps we are taking:
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Incorporating more information about outages: While our driver already handles dark traffic lights like four-way stops, we’re now rolling out fleet-wide updates that give our vehicles even more context about regional outages, allowing them to navigate these intersections more decisively.
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Updating our emergency preparedness and response: We will improve our emergency response protocols by incorporating lessons learned from this event. In San Francisco, we will continue to coordinate with Mayor Lurie’s team to identify areas of greater collaboration in our existing emergency preparedness plans.
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Expanding our first responder engagement: To date, we have trained more than 25,000 first responders in the United States and around the world on how to interact with Waymo. As we learn lessons from this and other widespread events, we will continue to update our first responder training.
Unwavering in our mission to make our streets safer
We live and work in San Francisco and are grateful to the city’s first responders for their tireless work, as well as to Mayor Lurie for his leadership.
Backed by over 100 million miles of fully autonomous driving experience and a save To improve road safety, we are not intimidated by the opportunity to challenge the status quo of our roadways, and we are proud to continue serving San Franciscan residents and visitors.
