Waymo is calling in cases to deal with the flooding problem

Waymo has released a software update for its fleet of nearly 4,000 vehicles to help them avoid flooded roads as part of a recall announced by the National Highway Traffic Safety Administration (NHTSA) on Tuesday.

But the company has not completely solved the problem of how its vehicles behave in these conditions. In documents released by NHTSA, the federal safety regulator says Waymo is still “developing the final remedy for this recall.”

The problem appears to be that Waymo’s robotaxis were slowing, but not stopping, when encountering flooded roads they couldn’t pass, according to NHTSA. Robotaxis using Waymo’s fifth- and sixth-generation autonomous vehicle systems are affected.

The recall applies to 3,791 vehicles, giving us a more up-to-date understanding of how many vehicles Waymo has on the roads in about a dozen U.S. cities, the regulator said.

Waymo has now issued several recalls for its self-driving cars. The company’s first recall came in February 2024 after it was discovered that two automated vehicles in Phoenix had separately collided with the same towed vehicle. Since then, Waymo has issued recalls to fix low-speed crashes with parking gates and telephone poles, as well as to address illegal driving near school buses.

Waymo decided to issue the recall in late April after a robotaxi had difficulty navigating flooding in central Texas. In one incident, an empty automated taxi was swept away in San Antonio. The company also temporarily suspended its operations in the city.

The initial update sent to its fleet places “restrictions at times and in locations where there is a high risk of encountering a flooded high-speed road,” according to the National Highway Traffic Safety Administration (NHTSA).

“We identified room for improvement regarding flooded and impassable lanes designated for high-speed roads, and made the decision to submit a voluntary software recall to NHTSA regarding this scenario,” Waymo said in a statement. “We are working to implement additional programmatic safeguards and put in place mitigation measures, including improving our severe weather operations during periods of heavy rainfall, which limits access to areas where flash flooding may occur.”