U.S. federal regulators have asked Zoox, Amazon’s self-driving unit, for more information in connection with an investigation into rear-end crash risks caused by unexpected braking.
The National Highway Traffic Safety Administration (NHTSA) initiated a preliminary investigation into Zoox on May 10 following two reports of Zoox vehicles unexpectedly braking, resulting in rear-end collisions with motorcyclists who sustained minor injuries. Zoox holds a permit from California’s Department of Motor Vehicles for testing its vehicles without a safety driver in Foster City and parts of San Francisco.
On Thursday, the agency set a deadline of July 12 for Zoox to provide additional information to support its investigation. The letter outlines 13 specific requests for information, including the number of miles driven on public roads with self-driving software activated by geographic region; the number of AV-commanded hard braking events with and without onboard human supervision; a list and summary of braking incidents; a detailed timeline of events starting 30 seconds before each incident; and copies of videos, graphical renderings of measured trajectories, and predicted paths for each road user beginning 30 seconds before each incident.
NHTSA confirmed from an initial investigation that both Zoox’s Toyota Highlanders were using the company’s autonomous vehicle software in the moments leading up to the collisions.
In a letter from NHTSA’s Office of Defects Investigation (ODI) dated May 30, the agency indicated that in both reported incidents, the Zoox vehicles applied the brakes in response to another road user who was not directly in front of them.
“ODI is concerned that vehicles exhibiting unexpected rapid braking may increase the risk of crash, property damage and injury,” the letter states. “The risk is particularly acute to road users behind the Zoox vehicles who are unable to reasonably anticipate or react to the unexpected sudden braking.”
The investigation will assess the performance of Zoox’s automated driving system, its behavior in crosswalks around vulnerable road users, and other similar rear-end collision scenarios.
The two incidents that prompted this investigation involved motorcyclists, who often trail closely behind cars and split lanes. NHTSA’s action in this matter may signal increased scrutiny of autonomous vehicle companies following GM’s Cruise losing its permits to operate in California after failing to disclose an incident where a Cruise robotaxi ran over and dragged a pedestrian for 20 feet.
Federal regulators are also investigating Alphabet’s Waymo after receiving 31 reports of its robotaxis making unexpected moves that resulted in crashes and potentially violated traffic safety laws.
