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Comment by semi-extrinsic | Hacker News Reader

This.

Notice how quick they are to bring up "this is the first fatality in 130 million miles", but AFAICT, traffic fatalities in the US occur at a frequency of around 10 per billion miles [1], which is the same.

So even though this is just one data point, it's spot on the current average for fatality frequency in normal cars.

Furthermore, to gather enough statistics to be able to say with confidence "semi-autonomous Teslas are/aren't safer than normal cars", Tesla either needs to increase their sales volume by several orders of magnitude, or we'll have to wait for ten years.

[1] https://en.wikipedia.org/wiki/List_of_motor_vehicle_deaths_i...

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Is there a statistical difference in accident rate between high and low income populations? If so, do we know what the fatality/miles rate is in the group that would be able to afford a tesla? When I read the blog post, I couldn't help but think that while tesla's rate might be smaller than the national average, it is also not a fair comparison to draw conclusions from.

IDK about statistical difference, but the mechanical difference between a brand new high-end full-size car and a twenty year old Honda Civic is going to be massive. Just look at the downward slope of that curve of fatalities per billion miles in each year. Also remember that those numbers are averages over the entire car population in each year, so most cars in the 2015 data are quite a bit older than 2015.

If we had data for the "high end modern full-size car" category, it would most definitely be lower than 10 fatalities per billion miles.

The IIHS compares car model fatality rates: http://www.iihs.org/iihs/topics/driver-death-rates

If you want to do the numbers to compare the Tesla to other cars, where they measure driver fatalities per million registered years, do this:

130,000,000 miles / 12,000 average miles per year per car = 10,833 years.

That's 10,833 registered years for the Model S.

The IIHS site normalizes to deaths per million registered years, so multiply that number by 92.3, and since we have one death so far, the Tesla Model S is now at 92.3 driver deaths per million registered car years.

Let's compare to other car models:

  Ford Taurus 2WD: 20 deaths
  Hyundai AccentL: 86 deaths
  Lexus LS 460 2WD: 18 deaths
  Acura TL 2WD: 5 deaths
  Audi A4 4WD: 0 deaths (yes, a bunch of car models had zero driver deaths)
  And average for ALL 2011 vehicles: 28 deaths.

So, right now, it looks like the Tesla Model S is about 4x deadlier than the average car when using Autopilot, and about 10-20x deadlier than the safest cars.

>So, right now, it looks like the Tesla Model S is about 4x deadlier than the average car when using Autopilot, and about 10-20x deadlier than the safest cars.

How you can draw such a conclusion from a singular data point? That's beyond ridiculous.

Seems as valid (and invalid) as the implied conclusion here:

> This is the first known fatality in just over 130 million miles where Autopilot was activated. Among all vehicles in the US, there is a fatality every 94 million miles. Worldwide, there is a fatality approximately every 60 million miles.

Fair enough. I think the framing matters a bit though.

"4 Times Deadlier!" certainly comes across as sensationalist based on such flimsy data (never mind that the real figure is actually 3.2 and the parent chose to round up rather than down to serve his/her purpose).

Whereas Tesla's statement comes across more as a statement of fact (albiet quite self-serving.. no question about that).

When these automated cars can complete a journey __without__ handing back to the human, only then can those journey miles be added to the miles driven under autopilot claim. Until such time, consider all automated cars a considerable risk to other road users.

How are you defining automated? No truly autonomous cars are available yet, so they're all some form of driver assist. How are these a risk to other road users, and at which point do they become a risk and not a safety benefit?

Auto-pilot is semi-autonomous... I gather you consider that a risk...

What about Subaru EyeSight? It can autonomously brake. I can drive for hours on the freeway without ever hitting the brake nor gas, even in stop and go traffic. It has warned me multiple times of a sudden slowdown just as I noticed it. It hasn't yet saved me from anything, but if any of those circumstances I'd been distracted (even for a legit reason) it could have. It once warned me of a motorcycle in my path on a very dark night when the dim tail-light of the motorcycle was overwhelmed by the much brighter tail-lights of the cars to its left and right. I would have seen it soon enough, but the car saw it first. Is that a risk to other road-users? Yet, it's automated by some definition.

What about various other manufacturer's lane keeping features? That automation to some degree.

What about ABS? Stability control? Again... automation to some degree.

All of these have their detractors, yet I think statistics clearly show an improvement with each level of driver assist.

The 130 million miles is not Model S overall, but Model S with autopilot engaged. It's also only the first 130 million miles, so the sample size is currently 1. This will be much more interesting to look at in 5 years, and at the moment it tells us nothing about Model S.

Having the same fatality statistic was not enough for Google to bring autonomous driving into production. Many people think that it should be at least an order of magnitude safer than manual driving

Sure. The problem with this is statistics: you need to have your autonomous cars travel at least 100 billion miles before you can confidently say they're an order of magnitude safer.

A normal car drives about 100 000 miles in 10 years. You then need one million autonomous cars driving around for a decade before you even know whether they're safer!

That's very true, but if you know your product well enough, and you perform well conducted experiments, you can come up with a good estimate for this without actually having your cars travel 100 billion miles.

Sure. The main issue with that is the unknown unknowns. In hypothetical cars an order of magnitude safer than today, we're talking about events so rare that a single (hypothetical) accident which kills all 7 passengers due to the Tesla misinterpreting an obscure Hungarian road sign meaning "bridge out ahead" will significantly influence your safety statistics.

There are enough youtube videos with people falling asleep in Tesla on the highway and a Tesla switching lanes and almost causing a frontal crash. These are known problems.

Maybe a billion miles are needed for a fatal crash, but for small mistakes it's much less.

> A normal car drives about 100 000 miles in 10 years.

Can you give a source for that number as it seems a bit low given warranty numbers.

my insurance estimates the average driven per year is around 12k miles so 100000 miles in 10 years is about right or a little low.

You don't need an equal sample size to determine if autonomous cars are safer. But if you're comparing to all the cars on the road today, you need quality data that matches the distribution of cars today. Google isn't going to prove that autonomous cars are safer if they only test in Palo Alto in ideal weather conditions.

Your statistics seems to be at odds with the statistics quoted in their post:

"Among all vehicles in the US, there is a fatality every 94 million miles. Worldwide, there is a fatality approximately every 60 million miles."

1/94 million is very close to 10/1000 million, which is what I said.

Close is not the same and neither is the same as 1/134 million. Of course I have no idea if the differences are statistically significant, and it's likely impossible to tell given the lack of data on Tesla autopilot at the moment (new).

Well of course it's not statistically significant, 1/134 is based on a single data point. At this level of confidence, all these numbers are equal. If this was the first fatality in 1000 million miles, it might be an indication of higher safety. Might.

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