Nov 9 (Reuters) - The US National Highway Traffic Safety Administration said on Monday it had opened a recall query into 2,895 vehicles operated by Alphabet's self-driving unit Waymo over continued traffic safety violations involving the vehicles' behavior when encountering school buses.
The probe will determine whether a software fix Waymo rolled out late last year failed to stop its driverless cars from passing school buses with flashing red lights, as most of the violations happened after the company
said the remedy was fully deployed.
NHTSA said it was reviewing whether a software update implemented by Waymo under a December 2025 recall adequately addressed a defect that could cause Waymo vehicles to pass school buses displaying flashing red lights or extended stop arms after initially slowing or stopping.
The auto safety regulator said most of the incidents occurred after November 2025, when Waymo said it had completed the software remedy for all affected vehicles.
The recall query will assess the adequacy of the remedy and determine the causes of the post-remedy incidents, NHTSA said.
Separately, NHTSA had opened a probe in January after one of Waymo's self-driving vehicles struck a child near an elementary school in Santa Monica, California.
In October last year, the NHTSA launched a preliminary probe into Waymo after reports emerged of robotaxis failing to obey traffic laws near school buses.
In Austin, Texas, the independent school district documented 19 distinct violations, including an incident where a driverless car briefly stopped but then proceeded while a student was actively crossing the street. Six other violations were recorded by public schools in Atlanta, Georgia.
Waymo announced a voluntary software recall in December affecting over 3,000 vehicles equipped with its fifth-generation automated driving system. The company said that the update had been fully deployed by mid-November to ensure cars appropriately slowed down and remained stationary.
(Reporting by Anna Peverieri in Barcelona and Akash Sriram in Bengaluru; Editing by Jochelle Mendonca and Mrigank Dhaniwala)
