An article from GCR pointing out Elon's use of "Lies, Damned Lies and Statistics" when talking about Autopilot's safety 'increase':
http://www.greencarreports.com/news/110 ... -elon-musk
How safe is Tesla Autopilot? Parsing the statistics (as suggested by Elon Musk)
. . . Apples vs oranges
Sample size notwithstanding, Tesla’s statistical claims also suffer from the old apples-vs-oranges conundrum. The NHTSA number that Musk presumably used to derive his one-fatality-every-94 million-mile benchmark is the Fatality Rate per 100 Million VMT (Vehicle Miles Traveled). For the last few years, that number has hovered a bit above 1.00, which translates to a miles-per-fatality number a bit under 100 million.
This traffic fatality number from the agency, however, happens to include bicycles, motorcycles, pedestrians, 18-wheelers and buses. In fact, only 36 percent of the “traffic fatalities” listed by NHTSA in 2015 were occupants of passenger cars. (Another 28 percent were classified as light trucks, most of them presumably SUVs and pick-ups.) Tesla’s statistical comparison essentially equates the Florida Autopilot crash fatality with a pedestrian being run over by a bus. This is apples-vs-aardvarks.
Because of these glaring representative-sample flaws, Tesla’s comparison “has no meaning,” according to Alain Kornhauser a Princeton transportation professor, quoted in MIT Technology Review.
Another professor, Bryant Walker Smith of the University of South Carolina, told Tech Review that comparing Autopilot miles to population-wide statistics was “ludicrous on the face of it. . . .”
The IIHS rated the cars in terms of driver deaths per million vehicle-years. Passenger deaths didn’t count. (A vehicle-year is a measure of exposure to risk: one vehicle on the road for one year.) The average for all 146 makes and models rated was 28 driver deaths per million vehicle-years, with a confidence range of 27 to 30.
(Confidence range is the range within which there is a 95-percent chance that the number is accurate. The higher the number of cars in the sample size, the tighter the confidence range.)
The IIHS’s figure is a much better number than NHTSA’s to compare with Tesla’s numbers for Autopilot driving. No bicycles, no 18-wheelers, no passengers or pedestrians. And a fairly tight window of confidence, based on the huge exposure of 63 million vehicle-years.
If we assume 12,000 miles per vehicle-year—the generally accepted figure—the IIHS number works out to 28 driver fatalities per 12 billion miles. That’s one driver fatality for every 428 million miles driven. Suddenly, the Autopilot Model S number that Tesla was bragging about last June—one death in 130 million miles—looks downright terrible.
By the IIHS yardstick, the Autopilot Tesla is more than three times as dangerous as a typical passenger vehicle, even with all the advantages cited above. . . .
And so on. Hopefully we can now all agree to consign Elon's claim based on 'statistics' to the realm of tabloid journalism ("Scientists detect huge human face on Mars") where it belongs.