Waymo Recalls 3,791 Robotaxis Over Floodwater Driving Flaw: What Went Wrong?

Waymo has initiated a recall of 3,791 robotaxis following an incident in which one of its autonomous vehicles drove into floodwaters in San Antonio, Texas. The company, owned by Alphabet (Google’s parent company), filed a notice with the National Highway Traffic Safety Administration (NHTSA) last week, revealing a broader issue with its fleet.

Waymo’s Robotaxis May Fail to Stop in Flooded Lanes

According to the NHTSA filing, Waymo’s autonomous vehicles operating on higher-speed roadways “may slow but not stop in response to detecting a potentially untraversable flooded lane.” This flaw has forced the company to implement temporary restrictions on its robotaxis’ access to high-speed routes vulnerable to flash flooding until a permanent fix is developed.

Waymo stated in a company announcement, as reported by Bloomberg:

“We are working to implement additional software safeguards and have put mitigations in place, including refining our extreme weather operations during periods of intense rain.”

April 20 Incident in San Antonio Leads to Recall

The recall stems from an incident on April 20, 2024, when a Waymo robotaxi encountered a flooded section of roadway with a 40 mph speed limit in San Antonio. Despite the hazardous conditions, the vehicle drove straight into the floodwater at a reduced speed instead of stopping or avoiding it, as outlined in the recall notice.

Local reports confirmed that the Waymo robotaxi was swept away by the floodwater and deposited into the Salado Creek. The vehicle was not recovered until four days later. Fortunately, no passengers were aboard the robotaxi during the incident.

Waymo’s History of Floodwater-Related Issues in San Antonio

This is not the first time Waymo’s robotaxis have struggled with floodwaters in San Antonio. Weeks prior to the April incident, another Waymo robotaxi became stuck in a mildly flooded crossing and required towing. While it was not swept away, the episode highlighted ongoing vulnerabilities in the company’s autonomous driving systems.

Water Proves Challenging for Autonomous Vehicles

Water appears to be a persistent challenge for autonomous vehicles. Recent footage from Austin, Texas, showed a Waymo robotaxi stopping abruptly in the middle of a busy roadway due to a shallow puddle, causing traffic congestion behind it.

Other autonomous vehicle systems have also faced difficulties in adverse conditions. Tesla’s Full Self-Driving (FSD) mode has struggled with navigation in fog and even direct sunlight, while its Robotaxi service drew criticism after footage showed one of its vehicles driving at high speeds through partially flooded streets in Austin. Additionally, Waymo’s fleet in San Francisco experienced significant disruptions in December 2023 when a power outage left traffic lights non-functional, causing chaos on the roads.

Broader Concerns Over Autonomous Vehicle Safety in Hazardous Conditions

The incidents raise serious questions about the ability of autonomous vehicles to handle hazardous or less-than-ideal road conditions. As self-driving technology continues to advance, ensuring safety in extreme weather and unpredictable environments remains a critical challenge for the industry.

For more on self-driving technology, read: China Halts Nationwide Self-Driving Taxi Services After Vehicles Block Streets.