The problem has raised questions over the ability of autonomous vehicles to adapt to unpredictable or real-world driving conditions.
Waymo autonomous vehicles (AVs) stopped and blocked traffic in San Francisco on Dec. 20 after traffic lights stopped working due to an electrical power outage caused by a substation fire, forcing the company to temporarily suspend services.
The robotaxi company said its vehicles are designed to treat nonfunctioning traffic lights as four-way stops, but that the scale of Saturday’s outage had created unusual conditions. Therefore, the company paused services, resuming on the afternoon of Dec. 21.
“While the failure of the utility infrastructure was significant, we are committed to ensuring our technology adjusts to traffic flow during such events,” a spokesperson for Waymo, owned by Google’s parent company Alphabet, said.
The spokesperson said that throughout the outage, Waymo coordinated closely with city officials. Most journeys were completed before vehicles were either returned to depots or pulled over.
The outage was caused by a fire at a substationat 8th and Mission streets on Saturday and left a large section of the city’s northern part without power, impacting 130,000 homes and businesses.
Power was restored to the bulk of customers by Dec. 21, with Pacific Gas and Electric Co (PG&E) continuing to work in the following days to restore electricity.
PG&E provided an update on X on Dec. 22, saying it was continuing repairs to restore power to the remaining 3,800 customers affected and that power should be fully restored by 6 a.m. local time on Dec. 23.
Concerns Over Autonomous Vehicles
The road-blocking problems have raised questions over the ability of autonomous vehicles to adapt to unpredictable or real-world driving conditions.
Philip Koopman, professor emeritus at Carnegie Mellon University and a specialist on self-driving vehicle safety, said the scale of the disruption was concerning, raising the prospect that thousands of robotaxis stopping during an emergency could pose a problem.
“What if this had been an earthquake? You would have thousands of robotaxis blocking the road,” Koopman said.
Earlier this month, footage of three Waymos went viral on social media after having a “standoff” on a street in San Francisco.
