Federal regulators spent the past six months investigating the role of Tesla Motors? Autopilot feature in a fatal car crash. Their findings reinforce what millions of drivers already know: Despite much hype about ?self-driving cars,? human beings remain responsible for understanding the capabilities and limitations of the vehicles they drive and accountable for their safe operation.
Officials from the National Highway Traffic Safety Administration (NHTSA) closed their probe of Tesla on January 19 without ordering a recall or taking any enforcement action. The examination found no faults within the Autopilot system and determined that it worked as intended during a May 7, 2016, crash that claimed the life of Joshua Brown, the first person killed in a crash attributable to a semi-autonomous feature. ?Not all systems can do all things,? NHTSA spokesman Bryan Thomas said Thursday.
Brown had engaged the Autopilot feature in his 2015 Tesla Model S as he traveled eastward along U.S. Highway 27 in Williston, Florida. Neither he nor the autonomous technology noticed when a tractor trailer made a left turn across the car?s path. The truck should have been visible to the driver for at least seven seconds before the fatal collision occurred, according to NHTSA?s summary of the investigation, enough time to notice that the car was not reacting to the hazard and to take evasive action.

In September, Tesla made changes to its Autopilot feature that emphasize the role of radar and cam...