Tesla’s Autopilot Vindicated With 40% Drop in Crashes

Tesla’s driver-assistance features, known collectively as Autopilot, have been vindicated.

The U.S. Department of Transportation 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 the feature. In fact, among the evidence disclosed by Tesla in the investigation is a crucial piece of data that’s so far 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 all Tesla vehicles come equipped with the hardware necessary for Autopilot, but for the software to operate, you need a software upgrade that costs thousands of dollars. Since buyers can add Autopilot features after purchase, this provides a perfect before-and-after comparison.

It turns out, according to the data Tesla provided to investigators, installing Autopilot prevents crashes—by an astonishing 40 percent. Approximately one-third of the mileage on the cars were driven before the upgrade to Autosteer (the most controversial component of the driving suite), while the remaining miles were accrued after installation.

Tesla’s reputation took a hit after it disclosed the driver death that triggered the federal probe, and it’s no exaggeration to say it changed the way people think about self-driving cars, despite the thousands of deaths annually tied to ordinary vehicles. Consumer Reports went so far as to call on Tesla to revoke the features until changes were made.

The only statistic that Tesla offered in its public defense at the time was flimsy: Teslas had been driven on Autopilot for 130 million miles before the first fatal crash, compared with a national U.S. rate of 94 million miles per fatality. With only one fatality, this was hardly good statistical evidence, especially when one considers that the Tesla Model S has the highest safety rating to begin with and Autopilot is only recommended for highway driving. Now for the first time, ironically thanks to an investigation that initially hurt the company, there is some real data—and it’s good news for Tesla.