The U.S. National Highway Traffic Safety Administration (NHTSA) said on Monday it has opened a preliminary probe into about 2,000 Waymo self-driving vehicles after reports that the company’s robotaxis may have failed to follow traffic safety laws around stopped school buses.
The probe is the latest federal review of self-driving systems as regulators scrutinize how driverless technologies interact with pedestrians, cyclists and other road users.
NHTSA said the Office of Defects Investigation opened the review after flagging a media report describing an incident in which a Waymo autonomous vehicle did not remain stationary when approaching a school bus with its red lights flashing, stop arm deployed and crossing control arm extended.
The report said the Waymo vehicle initially stopped beside the bus then maneuvered around its front, passing the extended stop arm and crossing control arm while students were disembarking.
A Waymo spokesperson said the company has “already developed and implemented improvements related to stopping for school buses and will land additional software updates in our next software release.”
The company added “driving safely around children has always been one of Waymo’s highest priorities. In the event referenced, the vehicle approached the school bus from an angle where the flashing lights and stop sign were not visible and drove slowly around the front of the bus before driving past it, keeping a safe distance from children.”
NHTSA said the vehicle involved was equipped with Waymo’s fifth-generation Automated Driving System (ADS) and was operating without a human safety driver at the time of the incident.
Waymo has said its robotaxi fleet numbers more than 1,500 vehicles operating across major U.S. cities, including Phoenix, Los Angeles, San Francisco and Austin.
The Alphabet-owned company also plans to expand internationally, with launches in cities including Tokyo and London in coming years.
