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Veservyesterday at 7:00 PM4 repliesview on HN

Err, that is not the desirable statistic you seem to think it is. American drivers average ~3 trillion miles per year [1]. That means ~7000 child pedestrian injurys per year [2] would be ~1 per 430 million miles. Waymo has done on the order of 100-200 million miles autonomously. So this would be ~2-4x more injurys than the human average.

However, the child pedestrian injury rate is only a official estimate (it is possible it may be undercounting relative to highly scrutinized Waymo vehicle-miles) and is a whole US average (it might not be a comparable operational domain), but absent more precise and better information, we should default to the calculation of 2-4x the rate.

[1] https://afdc.energy.gov/data/10315

[2] https://crashstats.nhtsa.dot.gov/Api/Public/Publication/8137...


Replies

10000truthsyesterday at 9:09 PM

I suspect that highway miles heavily skew this statistic. There's naturally far fewer pedestrians on highways (lower numerator), people travel longer distances on highways (higher denominator), and Waymo vehicles didn't drive on highways until recently. If you look only at non-highway miles, you'll get a much more accurate comparison.

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smarnachyesterday at 10:13 PM

> we should default to the calculation of 2-4x the rate.

No we should not. We should accept that we don't have any statistically meaningful number at all, since we only have a single incident.

Let's assume we roll a standard die once and it shows a six. Statistically, we only expect a six in one sixth of the cases. But we already got one on a single roll! Concluding Waymo vehicles hit 2 to 4 times as many children as human drivers is like concluding the die in the example is six times as likely to show a six as a fair die.

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Jblx2yesterday at 8:32 PM

Would this Waymo incident be counted as an injury? Sounds like the victim was relatively unharmed? Presumably there are human-driver incidents like this where a car hits a child at low speeds, with effectively no injuries, but is never recorded as such?

maerF0x0yesterday at 7:02 PM

If that's the case, then that's great info. Thank you for adding :)