[josefresco]

"have a significantly higher rate of crashes with a serious injury or fatality than the existing New York City for-hire fleet"

Ok

"Waymo's fleet has not yet driven enough miles to support that they are safer than for hire vehicle drivers."

If there's not enough data to show they're "safer" than there also isn't enough data to show they are "less safe".

[jfim]

Part of the issue is that KSI events are so rare, and it's the same issue that AV companies face. If it takes you millions of miles to encounter a single event, how can you even start to quantify the rate of events, and even prove a different rate?

To scale it in human terms, say that you're a human driver and you're 2x better than the average human driver. If you wanted to prove that you're better than the average driver, you'd need to drive multiple hundreds of millions of miles to statistically demonstrate so.

Given that the rate is significantly lower for taxi drivers in aggregate, to prove that they're safer than taxi drivers if Waymo is 2x safer, they'd still need to drive multiple billions of miles to statistically prove that they're safer.

[pedvide]

That depends on what your hypothesis is. If it is that Waymo cars are safer than for-hire (which I guess it's what Waymo claims), then you need enough data to reject the null hypothesis that they are equally safe. Right now there doesn't seem to be enough data to do this, so you can't conclude they are safer. They could be equally safe or more dangerous.

[tetha]

But how do you conclude then that they are less safe? They are neither proven to be more, less, or equally safe. So any statement of "more injuries" is as unfounded as "less injuries" or "just as many injuries".

That seems like the same statement, unless we apply stochastic class level subtlety.

[scarmig]

If a driver doesn't get into a crash after a single mile, you can't conclude that they are safer than the average driver. If a driver does get involved in a crash after a single mile, it's very likely that they are not safer than the average driver. It could of course be extraordinarily bad luck, but that's unlikely.

[tetha]

> If a driver does get involved in a crash after a single mile, it's very likely that they are not safer than the average driver. It could of course be extraordinarily bad luck, but that's unlikely.

This is not that simple. Emergency service vehicles are at a very high risk of collision when they pull out of the station and crossings close to the station, or when leaving a situation under time pressure. Busses are at an increased risk of collision when pulling away from a bus stop. Construction vehicles are at a high risk of collision when they pull away from a construction site at a busy road.

Hence why you need more data, after which average accidents per mile are a much stronger indicator.

[lokar]

I thought it was the reverse. Waymo wants to be compared to all drivers, this critic says they should be compared to taxi drivers.