A Utah driver turned on the semi-autonomous functions of her Tesla vehicle and then didn't touch the steering wheel again for 80 seconds before slamming into a firetruck stopped at a red light last week, a summary of data from the auto released Wednesday showed.
The police said in a statement that the driver, a 28-year-old woman, "admitted that she was looking at her phone prior to the collision".
The driver re-enabled Autopilot 1 minute and 22 seconds before the crash, let go of the wheel 2 seconds later and then didn't touch the wheel again before hitting the truck at 60 miles per hour (97 kph). She took her hands off the wheel more than a dozen times, twice for more than a minute each.
The woman suffered a broken foot and some abrasions from the air bag deployment but, according to police, escaped relatively unscathed from the crash that demolished the front end of the Tesla.
Police issued the driver a traffic citation for failure to keep proper lookout.
The driver of the firetruck was checked for whiplash injuries but did not go to the hospital. Each time she put her hands back on the wheel, she took them back off the wheel after a few seconds. "Tesla has always been clear that Autopilot doesn't make the vehicle impervious to all accidents".
The NHTSA said it "launched its special crash investigations team to gather information on the South Jordan, Utah, crash", and said it "will take appropriate action based on its review".
Tesla's Autopilot relies on a system of radar, cameras with 360-degree visibility and sensors to detect nearby objects and perform basic functions such as parking and steering. Tesla says the system is not created to avoid a collision and warns drivers not to rely on it entirely.
The driver engaged Autosteer and Traffic Aware Cruise Control on multiple occasions during this drive cycle.
The Utah accident is the latest incident involving an autonomous or semi-autonomous vehicle that has prompted scrutiny from federal regulators.
In January, a Model S hit a parked fire truck on a Southern California freeway, with the firefighters' union saying the driver said Autopilot had been on at the time of the crash. The Autopilot system was engaged in that crash.
In 2016, the driver of a Model S was killed when the vehicle crashed into a semi-truck in Florida.
The National Transportation Safety Board, a separate government agency that looks into accidents and makes safety recommendations, has said it is not investigating the Utah crash.