The National Highway Traffic Safety Administration (NHTSA) has identified at least 80 cases in which Tesla’s Full Self-Driving (Supervised) software violated traffic laws by running red lights or using the wrong lane, according to a new letter sent to the automaker this week.
NHTSA said in the letter that it has received 62 complaints from Tesla drivers, 14 reports filed by Tesla and four media reports describing possible violations. That’s an increase from the roughly 50 violations NHTSA cited when it opened an investigation into the conduct in October.
The federal safety agency’s Office of Defects Investigation (ODI) is investigating whether Tesla’s driver assistance software can “accurately detect and appropriately respond to traffic signals, signs and lane markings,” the letter said. ODI also evaluates whether Tesla’s software provides sufficient warnings to drivers in these situations. Tesla’s answers are due January 19, 2026.
The increase in complaints is notable in part because the original batch ODI reported in October included multiple reports from a particular intersection in Joppa, Maryland. Tesla told the agency at the time that it had already “taken action to address the problem at this intersection.” The agency did not say where, geographically, these newly reported incidents occurred. Tesla heavily edits its own submissions to the agency.
The new letter was sent to Tesla the same week that CEO Elon Musk claimed in a post on NHTSA did not respond to requests for comment on Musk’s statement.
The letter is intended to begin the discovery process for NHTSA and as such details a number of requests for information the agency has made to Tesla. For example, the agency is asking for data on how many Tesla vehicles are equipped with FSD and how often the software is enabled. ODI is also asking Tesla to transfer any customer complaints it has received regarding these specific issues with FSD, including from fleet operators and from any third-party lawsuits or arbitration proceedings.
This is the second investigation NHTSA has opened into Tesla’s FSD software. In October 2024, the agency began investigating how FSD handles low visibility situations, such as fog or extreme sunlight.
