It turns out that even San Francisco Mayor Daniel Lurie, who once declared that the city should be a testbed for emerging tech, has his limits. Especially when that emerging tech creates a massive hours-long traffic jam that leaves thousands at a standstill.

Mayor Lurie has asked state regulators to bolster rules for autonomous vehicles nearly two weeks after Waymo robotaxis became immobile in heavy July 4 traffic, ran out of power, and blocked key streets, further compounding the gridlock. The traffic jam, which trapped municipal shuttles, became a citywide problem that affected thousands of people.

In his letter to the state Department of Transportation, which was viewed by TechCrunch, Lurie pointed to two events — a widespread power outage in December and the Golden Gate Bridge fireworks show on July 4 that attracted 100,000 spectators — both of which led to dozens of stranded Waymo vehicles and paralyzed traffic. The San Francisco Chronicle first reported on the letter.

The events, he said in the letter, “demonstrated that California’s current regulatory framework does not adequately address how autonomous vehicles operate during major incidents, planned or not. California’s challenge now is not just whether autonomous vehicles can operate safely under normal conditions, but also whether they can perform reliably during extraordinary ones.”