Waymo has recalled 3,791 robotaxis after federal regulators confirmed a software defect in its automated driving systems could allow the vehicles to slow down and then proceed into standing water on higher-speed roadways, raising the risk of a crash or injury.
What the defect does
The voluntary recall affects 3,791 vehicles with fifth- and sixth-generation automated driving systems, which are programmed to “slow, but not stop” when they detect a potentially untraversable waterlogged road. Entering an untraversable flooded roadway can result in loss of vehicle control, NHTSA stated in its official recall documents.
The voluntary recall is for Waymo vehicles that use the company’s fifth and sixth generation automated driving systems, the U.S. auto safety regulator confirmed. Waymo LLC is headquartered at 1600 Amphitheatre Parkway, Mountain View, Calif. Waymo filed the voluntary recall with NHTSA on April 30.
San Antonio incident triggered the action
The recall traces back to an April 20 incident in San Antonio, where an unoccupied Waymo robotaxi encountered an untraversable flooded section of a roadway. Rather than routing around the danger, the vehicle proceeded into the floodwater at a reduced speed and was ultimately swept into Salado Creek. No passengers were on board, and no injuries were reported, but the car had to be recovered from the waterway days later. Incidents were also captured on camera in Austin, Texas, and other locations, showing Waymo vehicles driving onto a flooded road or stalling in traffic during heavy rain.
Waymo said it had “identified an area of improvement regarding untraversable flooded lanes specific to higher-speed roadways” and filed the voluntary recall accordingly.
The Waymo recall is one of a string of software-driven safety actions touching autonomous and driver-assist systems. NHTSA sent a letter dated July 8, 2026, to “Driverless Automated Driving System Developers,” warning that the agency had “identified a clear pattern of driverless AVs interfering with law enforcement and other first responders.” NHTSA said it had documented multiple instances in which AVs drove directly into active emergency scenes, blocked the paths of ambulances and firefighters, or failed to recognize and respond to basic safety conditions like flashing lights, flares, smoke, fire, and traffic cones. Safety scrutiny of automated systems has also extended to conventional vehicles, as seen when a repositioned radar box left an automatic braking system uncalibrated and produced a dangerously delayed stop on a commercial utility truck.
Interim fix already deployed
All affected vehicles received the interim update by April 20, 2026, before the recall was formally filed with the agency. According to NHTSA, the company temporarily narrowed its operating scope to increase weather-related restrictions and also updated its maps as it works to find a permanent solution.
The company said it is “working to implement additional software safeguards,” including refining “extreme weather operations” and “limiting access to areas where flash flooding might occur.” Waymo has not yet fully solved the problem; NHTSA documents state the company is still “developing the final remedy for this recall.”
Scale and safety context
Waymo said it “provides over half a million trips every week in some of the most challenging driving environments across the U.S.” The company now operates a commercial robotaxi service in 11 U.S. markets.
Waymo says its vehicles have driven more than 170 million miles autonomously and claims they have demonstrated a 13x reduction in serious-injury-or-worse crashes when compared to human drivers. The floodwater defect nonetheless illustrates the edge cases that remain unsolved as automated driving software is tested at commercial scale.
The challenge of getting on-board sensors and software to correctly classify road hazards sits alongside broader hardware pressures in the ADAS supply chain. A key memory chip used in vehicles with lane-keeping and driver-assist features has risen up to 70 percent in price this year, complicating the economics of rolling out and updating such systems.
Because Waymo owns the entire fleet of nearly 3,800 affected units, it was able to apply an interim remedy immediately without the need for traditional consumer notifications. NHTSA’s recall record for the action is publicly available on the agency’s website.
