Waymo’s robotaxis suffered a serious failure on Saturday when a power outage affecting a large part of San Francisco caused problems for its autonomous cars in the city.
Some 130,000 residents lost power to their homes and businesses, while the outage also knocked out traffic lights at major intersections, causing confusion for Waymo’s robotaxis. Many of the autonomous vehicles came to a halt at intersections, contributing to congestion beyond the disruption already caused by the blank traffic lights.
Waymo responded by suspending its robotaxi service as it waited for power — and the affected traffic lights — to come back online.
“We have temporarily suspended our ride-hailing services in the San Francisco Bay Area due to the widespread power outage,” Waymo said in a statement on Saturday. “Our teams are working diligently and in close coordination with city officials, and we are hopeful to bring our services back online soon.”
In a statement to Digital Trends on Sunday, Waymo said it’s now in the process of resuming its robotaxi services in the city, adding, “While the failure of the utility infrastructure was significant, we are committed to ensuring our technology adjusts to traffic flow during such events. Throughout the outage, we closely coordinated with San Francisco city officials. We are focused on rapidly integrating the lessons learned from this event, and are committed to earning and maintaining the trust of the communities we serve every day.”
The outage, caused by a fire at a Pacific Gas & Electric’s substation, started on Saturday morning, with power going down shortly after noon. By Sunday morning, power had been restored for around three-quarters of San Francisco’s affected customers.
The troubling incident appears to have exposed a weakness in the technology powering the Waymo robotaxis, as they were unable to handle blank traffic lights.
Never one to miss an opportunity, Tesla CEO Elon Musk wrote on X that “Tesla robotaxis were unaffected by the SF power outage.”
Tesla’s robotaxis currently operate with a safety driver behind the wheel who can take control of the vehicle at any time, while Waymo’s robotaxis have no one in the driving seat.
The different technologies powering their respective autonomous systems mean that Tesla’s cars may also be better equipped to handle a traffic light outage. Tesla cars, for example, rely on neural networks processing camera feeds to mimic human-like decisions in novel scenarios, a system that means it doesn’t need to depend entirely on maps. Waymo, meanwhile, deploys LiDAR, radar, and updated HD maps, but, as we saw at the weekend, struggles with unmapped changes like a traffic light outage, which effectively turns a controlled intersection into a four-way stop.
Waymo explained: “While the Waymo Driver [Waymo’s autonomous driving technology] is designed to treat non-functional signals as four-way stops, the sheer scale of the outage led to instances where vehicles remained stationary longer than usual to confirm the state of the affected intersections. This contributed to traffic friction during the height of the congestion.”