NHTSA investigations found 467 crashes involving Tesla's Autopilot, resulting in 54 injuries and 14 deaths. When investigating, NHTSA discovered that Tesla told them internal 'data and labeling limitations' prevented the company from uniformly identifying crashes with FSD engaged — effectively admitting possible under-reporting. Tesla's Autopilot design was found insufficient to maintain driver engagement. As of March 2026, NHTSA escalated its investigation to cover 3.2 million vehicles over Full Self-Driving crashes in reduced visibility conditions.