Tesla's Autopilot driver-assistance system was cleared by the nation's crash investigator of involvement in a fatal Model S crash. The National Transportation Safety Board has released its final report investigating the incident, which took place on April 17, 2021, in Spring, Texas.

The possible involvement of Autopilot was suggested in the wake of initial reports that one of the two occupants—specifically the driver—was found in the back seat of the car.

But NTSB investigators found that security video footage showed both men entering the car and sitting in the front seats before driving away. Analysis of the wreckage also showed that both front seatbelts were buckled at the time, and the steering wheel was buckled and broken. However, the driver was found in the rear of the car, presumably attempting to escape.

The NTSB said Tesla provided it with a remote telemetry stream called "D15," which captures the car's Autopilot status, alerts, and safety system interventions. "Review of the data indicated no use of the Autopilot system at any time during this ownership period of the vehicle, including the timeframe up to the last transmitted timestamp on April 17, 2021," the NTSB wrote (PDF).

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(Later in the report, the agency noted that "[t]he exact time of the last received remote telemetry stream timestamp (the “D15” data as described in the May 20, 2021 request), was on April 17, 2021 at 3:58:57 p.m. CST," which appears to predate the crash by just over five hours.)

The Model S did record the crash on its event data recorder. The final five seconds showed the car accelerating from 39 mph to 67 mph two seconds before hitting the tree at about 57 mph. "The application of the accelerator pedal ranged from 8% to 98% during the 5 seconds of recorded data, and there was no evidence of braking," the NTSB wrote. The car's event data recorder also showed both driver and passenger had their seatbelts buckled at the time and that the front airbags deployed.

Further, the NTSB established that Autopilot would not engage on a roadway without lane markings, as was the case in the Texas subdivision where the crash occurred, and that the car's adaptive cruise control would not have allowed it to reach such high speeds on that roadway.

The NTSB blamed the driver's excessive speed and loss of control on "impairment from alcohol intoxication in combination with the effects of two sedating antihistamines, resulting in a roadway departure, tree impact, and postcrash fire."