Waymo has initiated a voluntary recall of approximately 3,800 of its autonomous vehicles following a software flaw that allowed one of its driverless cars to enter a flooded roadway – raising fresh questions about how self-driving systems handle extreme weather conditions.
The U.S. National Highway Traffic Safety Administration confirmed the recall on Tuesday, noting it covers 3,791 Waymo vehicles equipped with the company's fifth and sixth generation automated driving systems.
The triggering incident took place on April 20, when an unoccupied Waymo robotaxi operating on a 40 mph highway approached a lane submerged in water. Despite its onboard sensors registering the flooding as potentially impassable, the vehicle slowed and continued through anyway. Reuters identified the location as San Antonio, Texas, where local reports noted the company briefly suspended service the following day amid heavy rainfall.
In filings submitted to the NHTSA, Waymo described a software condition in which vehicles could decelerate and then proceed through standing water on higher-speed roads – a scenario the system should have handled by stopping or rerouting entirely. The company acknowledged the gap and said a comprehensive software fix is still being developed.
As an interim measure, Waymo moved quickly the same day as the San Antonio incident to deploy updated operational controls, including new weather-related restrictions and revised mapping data used to guide vehicle navigation. The company said it is also working on "additional software safeguards" beyond the temporary patch.
In its public statement Tuesday, Waymo framed the recall as a proactive step, saying it had "identified an area of improvement regarding untraversable flooded lanes specific to higher-speed roadways" and chose to formally file a voluntary recall with the NHTSA rather than quietly push a background update.
Video footage from Austin and other cities had previously circulated online showing Waymo vehicles entering flooded streets or stalling in traffic during rainstorms – incidents that fueled public scrutiny of how the fleet performs in adverse conditions. The San Antonio flooding case appears to be the most serious documented instance to date.
The recall is not the company's first brush with public criticism over vehicle behavior. Waymo has previously faced complaints about its cars failing to yield to school buses in Austin, and in December, robotaxis in San Francisco were blamed for contributing to traffic gridlock when they stopped moving during a widespread power outage.
Waymo currently runs commercial robotaxi services across 11 U.S. markets. Cities with broad public access include San Francisco, Los Angeles, Phoenix, Austin, and Miami, while a handful of other markets remain available only to invited riders.
