Waymo has issued a software update for its autonomous vehicle fleet, addressing issues with flooded roads. The recall affects nearly 4,000 vehicles across several U.S. cities.

The problem stemmed from Waymo's robotaxis slowing down but not stopping when faced with impassable floodwaters on higher-speed roadways. This affected both the company’s fifth- and sixth-generation autonomous vehicle systems.

Waymo’s latest recall follows earlier issues, including crashes into towed vehicles and illegal driving near school buses. The company has paused operations in San Antonio after an incident where a robotaxi was swept away by floodwaters.

The update aims to better identify areas of high risk and restrict access during heavy rainfall. Waymo stated: 'We have identified an area of improvement regarding untraversable flooded lanes specific to higher-speed roadways, and have made the decision to file a voluntary software recall with NHTSA related to this scenario.'

The incident highlights the ongoing challenges in ensuring autonomous vehicles can handle extreme weather conditions safely.