What NASA could teach Tesla about the limits of autopilot

A Tesla Model S electric vehicle is shown in San Francisco, California. Tesla Motors says the Autopilot system for its Model S sedan "relieves drivers of the most tedious and potentially dangerous aspects of road travel." The second part of that promise was put in doubt by the fatal crash of a Model S earlier this year, when its Autopilot system failed to recognize a tractor-trailer turning in front of the vehicle. Tesla says the driver, Joshua Brown, also failed to notice the trailer in time to prevent a collision. In Tesla's own words, "the brake was not applied"--and the car plowed under the trailer at full speed, killing Brown.