Waymo, the subsidiary of Google parent Alphabet and US robotaxi leader, has recalled nearly 4,000 of its driverless cars after several incidents in which its robotaxis entered closed-off highway construction zones.

The recall, filed Wednesday with the federal road safety agency (NHTSA), covers 3,871 vehicles.

According to the filing, reviewed by AFP, "under certain circumstances, the autonomous vehicle may enter and drive at speed in freeway construction zones due to inappropriately prioritizing the avoidance of other freeway hazards and/or failing to recognize the construction zone," increasing the risk of a crash.


The company logged 13 incidents in April and May, six near Phoenix, Arizona, and seven in the San Francisco Bay Area.

Waymo suspended highway driving on May 19.

"The remedy is currently under development," the filing said. Its cars continue to operate on other roads.

"We identified an area of improvement regarding performance around freeway construction zones," a Waymo spokesperson said.

"We voluntarily restricted freeway operations last month while making improvements, proactively notified state and federal regulators, and decided to file a voluntary software recall with NHTSA."

This is Waymo's sixth recall, and its second in just over a month.

In May, the company recalled about 3,800 vehicles for driving onto flooded roads, and in December more than 3,000 over illegal school bus passing in Austin, Texas.

Waymo says its cars have driven more than 170 million miles (about 270 million kilometers) autonomously and claims 13 times fewer serious crashes than human drivers.

The recalls come amid rapid expansion.

Waymo raised $16 billion in February and plans to launch in more than 20 cities in 2026, including London and Tokyo, in a global race that pits it against rivals including China's Apollo Go from Baidu.