Waymo Ships Software Update After Blackout Paralyzes Its San Francisco Robotaxis

A city-wide blackout brought the future of driving to a standstill. After its robotaxis froze at intersections across San Francisco, Waymo announced Tuesday it's shipping a software update to help its vehicles navigate disabled traffic lights “more decisively.”

An Overabundance of Caution

According to a blog post from the company, Waymo’s self-driving system is designed to treat dead stoplights as four-way stops, just as human drivers are supposed to. That should have allowed for normal operation, but instead, many vehicles requested a “confirmation check” from Waymo’s remote fleet response team to verify the situation.

The problem arose from a “concentrated spike” in these requests due to the widespread nature of the outage, creating the congestion seen in videos. Waymo stated this system was built “out of an abundance of caution during our early deployment” and is now being refined to “match our current scale.” The company also noted that despite the high-profile stalls, its vehicles “successfully traversed more than 7,000 dark signals on Saturday.”

The Software Fix

The new fleet-wide update aims to solve the issue by providing the self-driving software with “specific power outage context,” allowing it to proceed without human confirmation. Waymo also said it will improve its emergency response protocols by “incorporating lessons from this event.”

Saturday’s mess is the latest example of how Waymo is still uncovering unforeseen issues in real-world conditions. The company previously had to ship updates after a National Highway Traffic Safety Administration (NHTSA) investigation prompted a recall over its robotaxis’ behavior around stopped school buses.