The National Highway Traffic Safety Administration (NHTSA) has queried Tesla about changes it recently made to the driver monitoring system used by Autopilot.
Regulators are understood to have sent a letter to Tesla after it was revealed the car manufacturer recently changed the way that the driver monitoring system works, meaning drivers can use Autopilot for longer periods of time before they are prompted to apply torque to the steering wheel.
“The resulting relaxation of controls designed to ensure that the driver remained engaged in the dynamic driving task could lead to greater driver inattention and failure of the driver to properly supervise Autopilot,” the letter read.
Read: U.S. Regulators Probing Autopilot Demand Updated Responses Soon From Tesla
The special order issued by NHTSA requested documents and explanations from Tesla about the change by August 25, including how many vehicles were affected by the change as well as why and when Tesla made the software changes. Auto News reports that Tesla complied with the deadline to provide this information and that the NHTSA’s response will be kept confidential.
The NHTSA has been investigating the Autopilot system for more than two years after it was revealed that more than a dozen Tesla vehicles using the system had crashed into emergency vehicles in the United States.
Earlier this month, acting NHTSA administrator Ann Carlson said that the agency’s ongoing probe of the Autopilot system would soon conclude, hinting that it could force Tesla to improve its driver monitoring system. Tesla has been criticized in the past for relying solely on torque being applied to the steering wheel to ensure the driver remains alert but for the past two years, has been using an in-car camera mounted near the rear-view mirror to monitor drivers.
