At 4:36 p.m. eastern daylight time on Saturday, May 7, 2016, a 2015 Tesla Model S 70D car, traveling eastbound on US Highway 27A (US-27A), west of Williston, Florida, struck a refrigerated semitrailer powered by a 2014 Freightliner Cascadia truck-tractor. At the time of the collision, the truck was making a left turn from westbound US-27A across the two eastbound travel lanes onto NE 140th Court, a local paved road. The car struck the right side of the semitrailer, crossed underneath it, and then went off the right roadside at a shallow angle. The impact with the underside of the semitrailer sheared off the roof of the car.
After leaving the roadway, the car continued through a drainage culvert and two wire fences. It then struck and broke a utility pole, rotated counterclockwise, and came to rest perpendicular to the highway in the front yard of a private residence. Meanwhile, the truck continued across the intersection and came to a stop on NE 140th Court, south of a retail business located on the intersection corner.
The driver and sole occupant of the car died in the crash; the commercial truck driver was not injured.
System performance data downloaded from the car indicated that the driver was operating it using the Traffic-Aware Cruise Control and Autosteer lane-keeping systems, which are automated vehicle control systems within Tesla’s Autopilot suite.
The National Transportation Safety Board (NTSB) became aware of the circumstances of the crash when the National Highway Traffic Safety Administration (NHTSA) began a defect investigation on June 28, 2016, which focused on the automatic emergency braking and Autopilot systems of the Tesla Models S and X, for model years 2014–2016. On learning of the May 7, 2016, Williston crash that prompted the NHTSA investigation, the NTSB initiated our investigation, which focused on the use of the Autopilot system.