Tesla’s FSD software faces highest level of US safety scrutiny

The National Highway Traffic Safety Administration (NHTSA), the U.S. automotive safety regulator, has escalated its investigation into Tesla’s Full Self-Driving (Supervised) software. On Thursday, the Office of Defects Investigation (ODI), which serves as the investigative arm of the NHTSA, announced that it has upgraded the probe to what is known as an “engineering analysis.” This represents the regulator’s highest level of scrutiny, a critical step that is often required before the agency mandates a vehicle recall. The upgrade intensifies an investigation that the ODI initially launched in October 2024 to evaluate the performance of the driver-assistance software in low-visibility conditions.

The regulatory action follows four reported crashes in low-visibility situations, one of which involved the death of a pedestrian. Beyond these initial incidents, the regulator is investigating more than 80 instances in which Tesla’s driver-assistance software “violated basic traffic safety laws.” Furthermore, the ODI believes there “could be an under-reporting of similar crashes” due to data collection and labeling limitations that Tesla reported to the safety agency.

The investigation has revealed significant concerns regarding how the software handles degraded environmental conditions. According to the ODI, “In the crashes that ODI has reviewed, the system did not detect common roadway conditions that impaired camera visibility and/or provide alerts when camera performance had deteriorated until immediately before the crash occurred.”

A review of Tesla’s responses by the regulator also revealed additional crashes that occurred in similar environments. In those cases, the system either did not detect a degraded state, or it failed to present the driver with an alert with adequate time for the driver to react. The ODI noted that in each of these crashes, the Full Self-Driving software also lost track of or never detected a lead vehicle in its path. Additionally, while Tesla began developing a software update to address these low-visibility issues in June 2024—prior to the opening of the formal probe—the company has not clarified to the ODI whether the update was actually deployed or which specific vehicles received it.

Why it matters

The upgrade to an “engineering analysis” is a critical regulatory milestone that often precedes a mandatory recall, signaling that the U.S. government is increasing pressure on Tesla regarding software performance and data transparency.