Waymo explained why its self-driving taxi was blocking streets in San Francisco during a power outage.

Google's parent company Alphabet's autonomous driving car company Waymo has stated that its autonomous vehicles perform as expected when encountering traffic signal lights going out at intersections, treating them as "four-way stops." The issue lies in the scale. The statement pointed out that when encountering out of order signal lights, Waymo "may occasionally request confirmation checks" to "ensure the safest choice is made." "While we successfully navigated over 7,000 out-of-order signal lights last Saturday, the power outage led to an instant surge in such requests." The company added, "This caused a backlog of tasks, resulting in response delays in some cases, exacerbating the congestion on already heavily congested streets." The company also stated that its suspension of services in San Francisco was due to city officials requesting the clearing of streets for emergency responders. Waymo added, "This ensures that we do not further exacerbate congestion or hinder emergency vehicles during peak rescue times."