Waymo to Report on Mass Stranding Event During SF December Blackout

San Francisco supervisors want Waymo to explain why a widespread power outage last December caused a mass-stranding of their robotaxis, and what they’re doing to prevent future meltdowns.

Calling for greater accountability, San Francisco District 5 Supervisor Bilal Mahmood told the company to report to City Hall on Monday and explain what caused vehicles to fail during the mass blackout.

“The purpose of the hearing is to get answers from Waymo about what were the causes of the technical failure for some of their vehicles that day,” Mahmood said, “and simultaneously, what are they doing to prevent this from happening again.”

On Dec. 20, a fire at a PG&E substation plunged over 130,000 of the utility’s customers — about a third of the city — into darkness. The blackout also disabled many of the city’s traffic lights, which in turn rendered many of Waymo’s self-driving cars nonfunctional.

The cars idled in the streets and blocked traffic as the company’s network became overwhelmed with assistance requests from the robotic cars. Waymo’s outage lasted into the next day, while some San Franciscans remained without power for days longer.

Mahmood, who recalls seeing traffic snarled as the robotaxis blocked darkened intersections in the city, said the impaired Waymo’s complicated emergency response efforts.

“ The stalled Waymos were actually disrupting emergency vehicles from accessing the PG&E substation that caused the fire in the first place,” said Mahmood, who is sponsoring Monday’s meeting of the Land Use and Transportation Committee, where Waymo is set to report.

Waymo did not respond to KQED’s request for comment. But, in a blog post shortly after the incident, representatives from the company said its cars successfully traversed over 7,000 dark signals during the initial stages of the power outage. Waymo representatives, however, have so far remained tight-lipped about the actual number of cars affected, with a lawyer for the company telling an administrative judge in January that the information was a “trade secret,” according to reporting from the San Francisco Chronicle.

In the December blog post, Waymo representatives wrote, “the scale of the outage and the sheer number of disabled traffic lights were the primary contributors to city-wide gridlock,” adding that it has taken steps to improve the company’s operations during future blackouts by updating software to respond to outages and changing the company’s emergency preparedness and response policies.

Mahmood said during the December outage, San Francisco Mayor Daniel Lurie had to personally call company leaders to get them to move the cars and allow emergency vehicles to access the burning substation.

While regulation of Waymo is largely handled at the state level, out of the jurisdiction of the city’s Board of Supervisors, Mahmood said the purpose of the informational hearing is to hold Waymo publicly accountable.

He added that at a recent meeting meant to hold PG&E to account for the substation fire and resulting power outage, he revealed previously undisclosed facts about the company’s response and has allowed the city to put pressure on the utility to make changes to its protocols.

“ We need to make sure that there is a precedent for good, sustainable emergency vehicle response, and what we saw in December [from Waymo] was not a good response,” Mahmood said. “The purpose of this hearing is to also to set an example to other companies, that if they want to do business in San Francisco, they have to make sure that they have the right procedures in place.”