Tesla Model S on Autopilot hits crossing truck near Williston, Florida
A Tesla Model S using Autopilot features struck a semitrailer turning across US-27A near Williston, Florida, on May 7, 2016, killing the car's driver.
Key facts
- The crash happened at 4:36 p.m. on Saturday, May 7, 2016, on US Highway 27A west of Williston, Florida.
- NTSB vehicle data showed the Tesla driver was using Traffic-Aware Cruise Control and Autosteer, both part of Tesla's Autopilot suite.
- The NTSB found the probable cause was the truck driver's failure to yield combined with the car driver's inattention due to overreliance on vehicle automation.
- The NTSB said the Tesla's operational design contributed by permitting prolonged driver disengagement and use of the automation in ways inconsistent with Tesla's guidance.
- NHTSA closed its own investigation in January 2017 without ordering a recall.
What happened
At 4:36 p.m. on Saturday, May 7, 2016, a 2015 Tesla Model S 70D was traveling east on US Highway 27A west of Williston, Florida. A 2014 Freightliner Cascadia truck-tractor pulling a refrigerated semitrailer was turning left from the westbound lanes onto NE 140th Court, crossing the Tesla’s path.
According to the NTSB, the car struck the right side of the semitrailer and passed underneath it, and the underside of the trailer sheared off the car’s roof. The Tesla then left the road at a shallow angle, went through a drainage culvert and two wire fences, broke a utility pole, rotated and came to rest in a residential front yard.
The Tesla’s driver, who was the only occupant, died. The truck driver was not injured.
The system involved
The car was a privately owned 2015 Tesla Model S 70D. NTSB vehicle data indicated the driver was using Traffic-Aware Cruise Control and Autosteer, the adaptive cruise control and lane-keeping features that Tesla markets together as Autopilot. These are driver-assistance features that require the driver to supervise the vehicle at all times.
Investigation and response
The NTSB investigated the crash (HWY16FH018) and published Highway Accident Report HAR-17-02. It determined that the probable cause was the truck driver’s failure to yield the right of way, combined with the car driver’s inattention due to overreliance on vehicle automation, which resulted in a lack of reaction to the truck. The board said the car’s operational design contributed by permitting prolonged disengagement from the driving task and use of the automation in ways inconsistent with the manufacturer’s guidance and warnings. It issued recommendations H-17-037 through H-17-043 to the US Department of Transportation, NHTSA, manufacturers of vehicles with Level 2 automation including Tesla, and two industry associations.
NHTSA opened a separate defect investigation and closed it on January 19, 2017. Consumer Reports reported that the agency found no evidence of a safety-related defect, said the system worked as designed, and concluded the crossing truck should have been visible to the driver for about seven seconds before impact. NHTSA also noted that Tesla had updated Autopilot in September 2016 to add hands-off warnings and to disable Autosteer for drivers who repeatedly ignored them.
Outcomes
- NHTSA closed its defect investigation on January 19, 2017, without identifying a safety-related defect or ordering a recall.
- The NTSB completed Highway Accident Report HAR-17-02 in September 2017 and issued safety recommendations H-17-037 through H-17-043.
- Tesla changed Autopilot in September 2016 to add hands-off-wheel warnings and to lock out Autosteer for drivers who repeatedly ignored them, according to Consumer Reports.