Tesla's 'Autopilot' results in 40% fewer crashes

"Tesla’s driver-assistance features, known collectively as Autopilot, have been vindicated.
The U.S. Department of Transportation has closed its investigation into a May 7 collision with a tractor-trailer that killed a driver using Autopilot. The agency found no indication of a safety problem with it. In fact, the evidence provided by Tesla included crucial data that’s been missing from the safety debate surrounding automated cars: crash rates.
Tesla is in a unique position to determine the precise impact of Autopilot on crash rates, more so than any other car manufacturer. That’s because while all Tesla vehicles come with the hardware necessary for Autopilot, you need a software upgrade that costs thousands of dollars to make it work. Since buyers can add Autopilot features after purchase, this provides a perfect before-and-after comparison.
It turns out that, according to the data Tesla gave investigators, installing Autopilot prevents crashes—by an astonishing 40 percent. The chart below comes from the report NHTSA issued while concluding its investigation. Approximately one-third of the mileage on the cars was logged before the upgrade to Autosteer (the most controversial component of the driving suite), while the remaining miles were accrued after installation."
Source:  Bloomberg, 19th January 2017