San Francisco seeks tougher robotaxi rules after Waymo meltdown fed holiday traffic chaos

SAN FRANCISCO (KGO) -- San Francisco Mayor Daniel Lurie is calling for new statewide standards governing autonomous vehicles during major events and emergencies after traffic gridlock involving Waymo vehicles during the city's Fourth of July celebrations.

In a letter to California's transportation secretary, Lurie urged stronger regulation of autonomous vehicles following congestion in San Francisco on July 4 and during a citywide power outage in December.

More than 100,000 people came to San Francisco for Fourth of July fireworks festivities.

RELATED: July 4 Waymo gridlock in SF after dozens choke streets, some lose power, 1 ran over lit fireworks

According to the letter, much of the traffic disruption was attributed to Waymo vehicles and gaps in existing state oversight. The letter said the incident "demonstrated that California's current regulatory framework does not adequately address how autonomous vehicles operate during major incidents, planned or not."

Some residents have called for Waymo vehicles to be kept off the streets during large events.

Lynnet Spiegel, who said she was stuck behind six Waymo vehicles during the holiday, said, "They definitely should not be around when there's big events happening because it just screws up the whole entire city."

MORE: 3 Waymo self-driving cars in 'standoff' cause traffic jam in San Francisco

Bryant Walker Smith, a law professor and transportation technology scholar, said restricting autonomous vehicles during major events could be a short-term solution in some situations but not a permanent one.

"You need to be able to get that janitor home in the middle of the night. You need to be able to get that emergency room technician into the hospital, and simply saying it's too hard. Sorry, we'll see you when things work better actually isn't an option," Smith said.

Lurie also said that during the July 4 gridlock, "reports indicated that public safety manual overrides did not work as designed" for Waymo vehicles.

Smith said the incident should be viewed as a warning sign.

"It is the early warning sign. It's the red flag that all is not right and that really does matter because next time it could be worse, next time things could line up in a different way and people could be trapped or firefighters could be impaired," he said.

The mayor is calling for a functioning override system, greater transparency before, during and after major events, and proof that autonomous vehicle systems can handle large-scale incidents.

MORE: Half-mile bus lines, crippling gridlock: SFMTA apologizes after massive July Fourth transit failures

In a statement, Waymo said it has successfully supported some of San Francisco's biggest events and will continue working with city agencies. The company said it is collaborating with officials on lessons learned from the millions of rides it has provided in San Francisco.

The renewed scrutiny comes as city leaders push for change they say are necessary to ensure autonomous vehicles can safely operate during emergencies and major public events.