Waymo explains why its robotaxis stopped working during a power outage

Waymo, a robotic taxi company, has explained the incident that left many of its vehicles stranded during a major power outage in San Francisco.

Autonomously navigating the real world: lessons from the PG&E outage

https://waymo.com/blog/2025/12/autonomously-navigating-the-real-world

Waymo explains why its robotaxis got stuck during the SF blackout | TechCrunch
https://techcrunch.com/2025/12/24/waymo-explains-why-its-robotaxis-got-stuck-during-the-sf-blackout/

On December 20, 2025, a planned power outage occurred in San Francisco, California, USA, causing Waymo robot taxis to become stranded all over the city.

Waymo suspends service in San Francisco after robot taxis get stranded due to power outage - GIGAZINE

Waymo explained, 'The scale of the rolling blackouts in San Francisco and the number of outages caused by traffic lights were the primary cause of traffic congestion throughout the city.' The outages caused traffic lights on major highways to stop working, leading to traffic jams and forcing police to manually manage intersections. As a result, the San Francisco Emergency Management Agency advised residents to stay home.

The outage caused traffic congestion in San Francisco even without Waymo robotaxis, but Waymo explained, 'Responding to an event of this magnitude posed an unprecedented challenge for self-driving technology. Waymo Driver (our self-driving technology) is designed to handle outages as a four-way stop, but may occasionally ask for confirmation to ensure the safest option is taken. While robotaxis successfully navigated over 7,000 outages on Saturday, the outage caused a barrage of these confirmation requests. This created backlogs and, in some cases, delayed responses, worsening congestion on already congested roads.'

Waymo explained that it meticulously established this verification protocol during the initial deployment, but that it plans to continue improving it based on the current scale at the time of writing. While the initial strategy was effective during small-scale outages, a fleet-wide update will provide Waymo Drivers with specific information about the outage's conditions, enabling more accurate navigation during larger outages.

Regarding the reason for the large number of robotaxis being stopped during the power outage, Waymo explained, 'Due to the ongoing power outage and city authorities' request that residents wait on the roads to allow emergency personnel priority, we temporarily suspended operations in the affected area. We parked vehicles in appropriate locations and instructed them to return one by one. This prevented further congestion and obstruction of emergency vehicles during the peak recovery period.'

In light of the recent large-scale power outage, Waymo explained that it will make the following three improvements:

- Integration of information about power outages
Waymo Driver currently processes dark traffic lights as a four-way stop, but we're updating it to give vehicles more information about localized outages so they can more accurately navigate intersections where the lights aren't illuminated.

Emergency preparedness and response updates
We will use lessons learned to improve our emergency response protocols, and in San Francisco, we will work with Mayor Lurie and his team to identify areas in our existing emergency response plans where we can work more closely together.

- Expanded support for emergency response personnel
We have trained more than 25,000 first responders in the U.S. and around the world on how to work with Waymo, and we will continue to update our training based on learnings from this and other extensive cases.