Waymo has temporarily halted its robotaxi services in four major US cities—Austin, Dallas, Houston, and San Antonio in Texas, plus Atlanta—after identifying a critical software vulnerability that could allow vehicles to drive into standing water on high-speed roads.

The Safety Issue

The problem was flagged in a National Highway Traffic Safety Administration (NHTSA) letter earlier this month. The software glitch causes affected vehicles to slow down and then drive directly into flooded roadways, creating significant safety risks during heavy rain.

Waymo responded by issuing a voluntary recall of nearly 3,800 robotaxis equipped with fifth and sixth-generation automated driving systems. The company is currently developing and implementing "additional software safeguards" to prevent the issue.

Current Status

Meanwhile, Waymo has also temporarily suspended service on freeways in San Francisco, Los Angeles, Phoenix, and Miami while the company evaluates performance in construction zones. An unoccupied Waymo robotaxi was trapped in floodwater in Atlanta, highlighting the real-world impact of the issue.

Despite the setback, Waymo says safety remains its "highest priority" and expects to resume service in the affected cities soon. The company continues to monitor weather forecasts and live conditions before returning to normal operations.

What This Means

This incident underscores one of autonomous vehicle technology's toughest challenges: handling unexpected environmental conditions. While Waymo's fleet is sophisticated—providing over 500,000 trips per week across multiple cities—edge cases like flooded roads remain dangerous. The swift recall and fix suggest mature safety practices, but this won't be the last weather-related issue autonomous fleets face as climate patterns shift.

Source: BBC News - Waymo pauses robotaxis