The company added that "Tesla drivers have logged more than one billion miles with Autopilot engaged, and our data shows that, when used properly by an attentive driver who is prepared to take control at all times, drivers supported by Autopilot are safer than those operating without assistance". The vehicle did not detect the driver's hands on the wheel for eight seconds. Preliminary vehicle data show that the Tesla was traveling about 68 miles per hour when it struck the semitrailer. "Neither the preliminary data nor the videos indicate that the driver or [Autopilot] executed evasive maneuvers".
According to NTSB investigators, Tesla's advanced driver assistance system (ADAS), Autopilot, was engaged about 10 seconds before impact.
The Palm Beach County Sheriff's Office said the tractor trailer pulled into the path of the Tesla, and the Tesla's roof was sheared off as it passed underneath the semi. As a result, Tesla shorted the time Autopilot issues a warning alert when the driver's hands are off the wheel. The Tesla continued driving for several blocks before it came to a stop after the crash. This isn't the first documented crash that involved active use of Autopilot, and while it's easy to point fingers at the system or at Tesla, these incidents are much more complicated. GM's Super Cruise driver assist system only operates on divided highways with no median turn lanes, he said.
Tesla has since phased in a requirement that the driver touch the steering wheel and apply a small amount of torque to it every 20-25 seconds.
"Tesla has for too always been using human drivers as guinea pigs", he said.
David Friedman, a former acting NHTSA administrator, said the incident raises serious questions about the system and the lack of restrictions on its use.
NHTSA said Thursday that its investigation is continuing and its findings will be made public when it's completed. "Tesla is long on big claims and short on proof". The NTSB used video from a nearby surveillance camera showing the collision and the video devices that Teslas use to help them steer and perform other functions.
The NTSB preliminary report on the March 1 collision doesn't spell out what the car's sensors detected as the vehicle approached the truck. A research paper released earlier this year by MIT scientists studying Tesla's driving-assistance system found that in the context of "tricky situations" - scenarios that may lead to property damage, injury or death - drivers disengaged Autopilot on average every 9.2 miles. The report said that despite upgrades to the system, Tesla did not incorporate protections against use of the system on other types of roads. Rather, the systems are created to detect vehicles they are following to prevent rear-end collisions.