Tesla did not respond to a request for comment, but the company has previously said that Autopilot makes its vehicles safer. In the fourth quarter of 2019, the company reported one accident for every three million miles driven in a Tesla with Autopilot engaged. Over all, the national rate was one accident for every 498,000 miles driven in 2017, according to N.H.T.S.A.
Still, the electric carmaker faces scrutiny on multiple fronts. The N.T.S.B. and the traffic safety administration are currently investigating more than a dozen crashes in which Autopilot might have played a role.
In the 2018 accident, Autopilot had been engaged for nearly 19 minutes, according to the safety board’s investigation. Mr. Huang put his hands on and off the wheel several times during that period and, in the final minute before the crash, the vehicle detected his hands on the wheel three times for a total of 34 seconds. It did not detect his hands on the wheel in the six seconds before impact.
Tesla’s event data recorders routinely collect a wide variety of information, such as location, speed, seatbelt status, the position of the driver’s seat, the rotation angle of the steering wheel and pressure on the accelerator pedal.
Mr. Huang had been traveling in his 2017 Tesla Model X sport utility vehicle on U.S. 101 in Mountain View when the car struck a median barrier at about 71 miles per hour. The speed limit was 65 m.p.h. The collision spun the car, which later hit two other vehicles and caught fire.
Mr. Huang had previously complained to family of problems with Autopilot along that stretch of highway, his brother told investigators. Data from the vehicle confirmed at least one similar episode near the area dividing the two highways, according to documents from the investigation.
The first known fatal crash with Autopilot in use occurred in May 2016 in Florida, when a Tesla failed to stop for a truck that was turning in front of it on a Florida highway. The vehicle hit the trailer, continued traveling underneath it and veered off the road. The driver of that car, Joshua Brown, was killed in the accident.