Waymo's self-driving taxis were "frozen" during a power outage in San Francisco.

On December 21, 2025, a substation fire in San Francisco caused a widespread power outage, affecting over 130,000 users. Waymo's driverless taxis suddenly "froze," stopping in the middle of the road, disrupting service and severely congesting traffic. This incident exposed a fatal flaw in current Level 4 autonomous driving systems: their heavy reliance on infrastructure and high-precision maps. Waymo responded by stating, "We are working closely with the city government to restore service as quickly as possible," and emphasizing that its design principle is "safety first."