Preliminary Evaluation · Closed
Rear-end Collisions Involving Zoox Vehicles
Manufacturer: Zoox, Inc.
This investigation led to a recall
NHTSA links this probe to recall campaign 25E019.
Campaign 25E019 predates our recall archive — check NHTSA.gov for details.
What NHTSA is examining
On May 10, 2024, the Office of Defects Investigation (ODI) opened a Preliminary Evaluation (PE24015) to assess reports of sudden unexpected braking in Zoox vehicles, leading to rear-end collisions, as well as to evaluate the performance of the Zoox Automated Driving System in crosswalks around vulnerable road users and in other similar rear-end collision scenarios. These unexpected braking events can increase the risk of a collision. To assess these risks, ODI collected information from Zoox as part of this investigation. In response to ODI’s Request for Information, Zoox provided information describing hard braking events commanded by the ADS. These hard braking events were identified by certain thresholds, including rate of deceleration. ODI analyzed the hard braking events commanded by the Zoox ADS and determined that Zoox ADS-equipped vehicles contributed to 4 collisions. Each of these collisions involved a vulnerable road user, with three of the incidents resulting in injury. Three of the collisions were reported under Standing General Order 2021-01 (SGO), while the other collision was not reportable under the SGO. On March 13, 2025, Zoox filed a safety recall (NHTSA Recall No. 25E019) stating that in specific circumstances “the Zoox ADS software may have reacted over-cautiously and braked unnecessarily hard” and that “the Zoox ADS software may have incorrectly anticipated a collision and braked unnecessarily hard.” These behaviors could lead to increased risk of a…
Vehicles under investigation
Source: NHTSA Office of Defects Investigation records, updated daily. An investigation is not a determination that a defect exists; many probes close without a recall.