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Comment by WarmWash | Hacker News Reader

If waymo is to be believed, they hit the kid at 6mph and estimated that a human driver at full attention would have hit the kid at 14 mph. The waymo was traveling 17mph. The situation of "kid running out between cars" will likley never be solved either, because even with sub nanosecond reaction time, the car's mass and tire's traction physically caps how fast a change in velocity can happen.

I don't think we will ever see the video, as any contact is overall viewed negatively by the general public, but for non-hyperbolic types it would probably be pretty impressive.

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That doesn't mean it can't be solved. Don't drive faster than you can see. If you're driving 6 feet from a parked car, you can go slow enough to stop assuming a worst case of a sprinter waiting to leap out at every moment.

If we adopted that level of risk, we'd have 5mph speed limits on every street with parking. As a society, we've decided that's overly cautious.

But with waymos it would be possible. Mark those streets as "extremely slow" and never go there unless you are dropping someone off. (The computer has more patience than human drivers.)

If that's too annoying then bad parking by school areas so the situation doesn't happen.

I don't know if you've been to some cities or neighborhoods but almost every street has on-street parking in many of them.

And why would you make Waymo's go slower than human drivers, when it's the human drivers with worse reaction times? I had interpreted the suggestion as applying to all drivers.

Oh I have no problem believing that this particular situation would have been handled better by a human. I just want hard figures saying that (say) this happens 100x more rarely with robotaxis than human drivers.

> The situation of "kid running out between cars" will likley never be solved

Nuanced disagree (i agree with your physics), in that an element of the issue is design. Kids running out between cars _on streets that stack building --> yard --> sidewalk --> parked cars --> driving cars.

One simple change could be adding a chain link fence / boundary between parked cars and driving cars, increasing the visibility and time.

How do you add a chain link fence between the parked and driving cars for on-street parking?

there's still an inlet and outlet (kinda like hotel pickup/drop off loops). It's not absolutely perfect, but it constrains the space of where kids can dart from every parked car to 2 places.

Also the point isn't the specifics, the point is that the current design is not optimal, it's just the incumbent.

Ok, that's not really a simple change anymore, because you need more space for that. Unless it's really just a drop off queue, but then it's not parked cars, since a parked car blocks the queue.

We would really need to see the site to have an idea of the constraints, Santa Monica has some places where additional roadway can be accomodated and some places where that's not really an option.

Second-order benefit: More Waymos = fewer parked cars

In high parking contention areas, I think there's enough latent demand for parking that you wouldn't observe fewer parked cars until reduce demand by a much greater amount.

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