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Comment by base698 | Hacker News Reader

I actually worked out the math on this--Tesla is lying with statistics when they made this comment they did about 1 in 130 million miles.

Here's what I did:

  1 in 90 million rate: 1.1 x 10^8
  Probability of No accident in one mile: 1 - 1.1 x 108 = ~9.9999999 x 10^8
  Probability of No accident and driving 130 million miles: (9.99999999 x 10 ^ 8) ^ 130e6 = 0.24
  Probability AT LEAST ONE ACCIDENT in 130 million miles = 1 - 0.24 = 0.76

If you do the same for a rate of 1 in 130 miles you get: 0.63.

So the true rate could really be worse than 1 in 90 million miles and they just got lucky that no incident prevented itself, which would make it more dangerous than a regular car.

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Another guy said on divided roads the rate is only about one per 150 million miles [1]

And, that still includes motorcycle accident rates which shouldn't be included in a comparison to Teslas.

[1] https://www.reddit.com/r/technology/comments/4sgxv1/while_te...

In other words, the exact rate is very uncertain when there's only one crash data point. They might be lucky (or unlucky). Well that's obvious, and I wouldn't call it lying at all.

It is misleading though...

I agree that the fatality rate does not allow for any comparisons. Autopilot could cause significantly more or fewer fatalities than humans.

On the other hand, one also needs to consider accident rate. From what I understand, based on US averages, we should have had 50+ accidents out of 100+ million miles driven on AP, but we had about three.

Also, are they counting all previous versions of the software instead of just the latest?

Moreover, I wonder how the human drivers in the statistics fare if you correct for drunk driving / using cellphone, etc. In my opinion, any autopilot worth it's name should be an order of magnitude better than the average human driver.

Averages are a bad way to look at the overall risk.

An example:

  Every time the auto pilot encounters a truck turning in front results in a fatality.
  1 in 10 times a drunk driver fails to avoid the truck turning in time.

The average overall for drunk driver could be 1 in 50 million miles and the auto pilot 1 in 90 million, but you are certain to die in a few instances with the auto pilot, but the human could possibly save himself in the same situation. I imagine the Tesla has lots of these bugs that haven't been found yet.

I would trust a drunk driver over Tesla's autopilot at this point. Don't die for Elon Musk's dream--being one of the first auto pilot fatalities isn't that big of an accomplishment.

Also, I'd give "Technopoly" a read.

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