AI + ML

Waymo recalls 3,800 robotaxis after one drove itself into a flood

Nothing like a partly submerged self-driving car to dampen public trust in autonomous vehicles

Waymo is recalling almost 3,800 robotaxis amid fears they may go off-script and drive into floods on high-speed roads.

All 3,791 cars running Waymo’s fifth and sixth-generation Automated Driving Systems (ADS) are being taken off the road before they potentially injure passengers.

"The software may allow the vehicle to slow and then drive into standing water on higher speed roadways," Waymo said in a letter [PDF] to the National Highway Traffic Safety Administration (NHTSA) this week.

"Entering a flooded roadway can cause a loss of vehicle control, increasing the risk of a crash or injury."

The Alphabet-owned robotaxi biz said all affected cars received an update on April 20, which increased "weather-related constraints and updated the vehicle maps," which served as an "interim remedy" while it works on a more permanent solution.

This coincided with a case in San Antonio, Texas, on April 20, in which a car was caught on video - shared with broadcaster KSAT 12 - driving into floodwater and becoming stuck.  

“On 4/20/2026, an unoccupied Waymo AV encountered an untraversable flooded section of a roadway that has a 40 mph speed limit,” the company wrote in one document [PDF] supporting the recall notice. 

“The Waymo AV detected potentially untraversable flood water and proceeded at reduced speed.”

Waymo temporarily suspended its services in San Antonio as a result and started pulling cars from the city’s fleet days after. The suspension remains in place today.

The Register asked Waymo for more information.

The company currently operates 24/7 driverless robotaxi services in Dallas, Houston, Los Angeles, Miami, Nashville, Orlando, Phoenix, and the San Francisco Bay Area.

Waymo has also set its sights on launching in London in September, its first foray outside the US, pending necessary regulatory changes that would allow driverless cars to operate in the city.

Test cars have already been spotted on the capital’s streets with trained experts behind the wheel, should any of the cars encounter issues, much like the deal Waymo agreed to in New York when the state handed its testing license back.

As The Register previously reported, given the differences in the roads and other motoring infrastructure between the US and UK, Waymo will have to overcome unique challenges before opening its car doors to the public.

In testing these vehicles now, Waymo is building a base of evidence to support its bid to operate in the UK.

In recent years, however, the company has had to tackle some tricky PR hiccups, mainly related to safety – an issue that autonomous car companies often claim their tech will help improve, not hinder.

Reports of serious issues, including cars ignoring red lights and veering into moving traffic, and killing dogs, sit alongside evidence of the technology helping to avoid potential freeway pile-ups, like a recent Waymo case study in LA shows.

Serious issues continue to plague cars, and while they attract more media scrutiny than equivalent human-driver mishaps, public trust will remain strained until cases become far rarer. ®