Fed’s probe of hard braking in Cruise robotaxi crashes ends after recall

Following a successful recall, federal safety investigators have concluded an investigation that was sparked after a number of Cruise robotaxis crashed after braking inappropriately when being followed by other cars. It’s a spot of good news for the autonomous driving startup, which has been under heavy scrutiny by federal and state regulators lately.

The National Highway Traffic Safety Administration’s Office of Defects Investigation opened a preliminary evaluation in December 2022 after reports emerged that Cruise’s robotaxis could engage in “inappropriately hard braking” or become immobilized while driving, thus becoming obstacles and potentially causing a crash.

At the time, NHTSA had three reports of Cruise robotaxis braking hard in response to another vehicle or cyclist approaching quickly from behind, resulting in the robotaxi being rear-ended.

NHTSA’s investigation, which also collected information from five other AV startups (Aurora, AutoX, Motional, Waymo, and Zoox) to use as comparisons to Cruise, found 7,632 hard-braking events in Cruise’s data, which it said were “determined by certain thresholds, including rate of deceleration, without regard to the appropriateness of the braking.”

In total, NHTSA identified 10 crashes that were caused by inappropriately hard braking by a Cruise robotaxi, four of which also involved a vulnerable road user and ended in injury.

Other reports submitted to the regulators told of multiple instances where Cruise’s vehicles stopped mid-journey, sometimes stranding passengers in unsafe locations like the middle of an intersection. None of these incidents resulted in a crash or injury, and the safety risk was very dependent upon where it took place, NHTSA wrote.

It’s fixed now

Earlier this month, Cruise initiated a safety recall, pushing out new software due to meetings between the AV developer and NHTSA to go over the data from Cruise and its peers. The recall notes that software updates between 2024 and May 2024 reduced the propensity for this problem to occur, thanks to improvements in how the robotaxis perceive, predict, and plan.

“In view of the recall action taken by Cruise and ODI’s analysis of the available data, including data presented by Cruise demonstrating a reduced occurrence of hard braking incidents after the software updates, ODI is closing this Preliminary Evaluation,” NHTSA wrote.

“We are committed to building trust and increasing transparency with respect to autonomous vehicle technology and look forward to our continued work with NHTSA toward that end,” a Cruise spokesperson told Ars.

That work will continue in the context of a second safety investigation opened last October after a pedestrian was hit by another car and then dragged down the road underneath the Cruise robotaxi. That incident also resulted in California suspending Cruise’s license and the departure of then-CEO Kyle Vogt.