The U.S. National Highway Traffic Safety Administration has terminated its investigation into unexpected deceleration occurrences involving approximately 695,000 Tesla vehicles, the agency said on Thursday. The probe, which focused on Tesla's Model 3 and Model Y models, was opened in 2022.
According to the regulator, the decision to close the inquiry was driven by a low demonstrated hazard to drivers and a pronounced drop in the number of incident reports over time. The agency's records show reported incidents fell from 300 at the outset of the investigation to 45 in 2024, then to 19 in 2025, and to three since the start of 2026.
Tesla issued software updates in early 2022 intended to address the unexpected deceleration issue. The NHTSA said those reported conditions did not alter the vehicle's lateral position within lanes, nor did they produce a meaningful reduction in the distance between the affected vehicle and any following vehicle that would be likely to cause a collision.
In a related regulatory development, NHTSA also closed an expanded probe last week that covered an estimated 376,241 Model 3 and Model Y vehicles over reports of loss of steering control. Both closures reflect actions by the regulator to evaluate and then conclude inquiries where it determined remaining risk was limited based on available reports and assessments.
Timeline and reported incidents
The investigation that began in 2022 tracked incident-report trends across subsequent years. Report counts published by the agency show a steady decline: 300 reports when the probe opened; 45 reports in 2024; 19 in 2025; and three reported incidents since the beginning of 2026. Those figures were cited by the NHTSA as part of its rationale for ending the deceleration probe.
Regulatory findings
In describing its findings, the NHTSA stated that the reported conditions linked to unexpected deceleration did not change how vehicles were positioned laterally in lanes and did not materially reduce spacing behind other vehicles in a way that would likely lead to a collision. The agency characterized the demonstrated hazard as low.
Context for manufacturers and markets
While the agency's actions close two separate inquiries into Model 3 and Model Y vehicles, the regulator's published incident counts show some reports continued into 2026. The NHTSA's determinations on both unexpected deceleration and loss of steering control were based on the agency's review of reported incidents and technical assessments.
Key points
- NHTSA closed its probe into unexpected deceleration affecting about 695,000 Tesla Model 3 and Model Y vehicles, citing low demonstrated hazard and falling incident counts.
- Incident reports declined from 300 at the investigation's start to 45 in 2024, 19 in 2025, and three since the beginning of 2026.
- NHTSA said the reported conditions did not change lateral lane positioning or cause a meaningful reduction in following distance; a separate expanded probe into steering control covering about 376,241 vehicles was closed last week.
Risks and uncertainties
- A small number of incidents were still reported in 2026, indicating residual reports remained despite the overall decline; this affects the automotive and vehicle safety oversight sectors.
- The NHTSA's closure decisions rely on reported incident data and the regulator's assessment that the conditions did not create a meaningful collision risk; ongoing monitoring by regulators and manufacturers may continue to influence perceptions in the automotive sector.