The National Highway Traffic Safety Administration said on Friday it is seeking information from Tesla about a new driver assistance mode dubbed “Mad Max” that operates at higher speeds than other versions.

Some drivers on social media report that Tesla vehicles equipped with the more aggressive version of its Full Self-Driving system may operate above posted speed limits.

“NHTSA is in contact with the manufacturer to gather additional information,” the agency said. “The human behind the wheel is fully responsible for driving the vehicle and complying with all traffic safety laws.”

Earlier this month, the safety agency opened an investigation into 2.9 million Tesla vehicles equipped with its FSD system due to the dozens of reports of traffic-safety violations and crashes.

The NHTSA said in opening the investigation, it is reviewing 58 reports of issues involving traffic safety violations when using FSD, including 14 crashes and 23 injuries.

Tesla did not immediately respond to a request for comment, instead reposting a social media post that described Mad Max mode as accelerating and weaving “through traffic at an incredible pace, all while still being super smooth. It drives your car like a sports car. If you are running late, this is the mode for you.”

The agency explained earlier this month that FSD – an assistance system that requires drivers to pay attention and intervene if needed – has “induced vehicle behavior that violated traffic safety laws.”

The agency said it has six reports in which a Tesla vehicle, operating with FSD engaged, “approached an intersection with a red traffic signal, continued to travel into the intersection against the red light and was subsequently involved in a crash with other motor vehicles.”

Tesla says FSD “will drive you almost anywhere with your active supervision, requiring minimal intervention,” but does not make the car self-driving.

Tesla’s FSD, which is more advanced than its Autopilot system, has been under investigation by the NHTSA for a year.

In October 2024, the NHTSA opened an investigation into 2.4 million Tesla vehicles with FSD after four collisions in conditions of reduced roadway visibility.

The Washington Post had previously reported the agency’s interest in the Mad Max mode.

(Reporting by David Shepardson; Editing by Chizu Nomiyama and Bill Berkrot)