To be clear and dispel your misconception:

These cars estimate rather than ‘know’.

In the same way a highway cop's lidar gun estimates.

They objectively know in a much truer sense than any human.

(Vehicle) Lidar/image multi-point calculation against a precision chronometer

(Human) Parallax and object size change estimation against an extremely irregular, low-precision chronometer

LOL. Tell race car drivers and truckers that they're inferior. Their senses are probably tuned just as finely as any vision system. You really discount non-quantitative measurements - as most tech people here do. You are wrong, though, that the best of the meat brains are so inferior.

The only thing wrong with non-quantitative measurements is that physics has a well-known quantitative bias.

Really they both estimate, but the vehicle tends to have smaller error bars on its estimates. Which still goes to your point.

Humans are terrible at high velocity estimates. That's one of the conditions described in the accident investigation report for that Irish plane which smashed a bunch of runway lighting due to insufficient take off power.

A brand new top of the line passenger jet would say e.g. "Caution: Acceleration" because it can work out the velocity of the plane, from there the acceleration and the remaining runway length (it uses GPS to identify the runway it's on) and take off speed and conclude we won't make it. Humans only decide that after it's far too late. Because it's much earlier the annunciation allows pilots to abort takeoff and investigate from the safety of the ground - in the Irish case they'd typed the wrong air temperature in and thus the engine performance was much worse than expected, with the right air temp it would have flown just fine

With a limited understanding of truth and know, yes.

but they don't know capabilities orf vehicles, say a vespa vs some sports bike.

While humans do and will behave differently around these vehicles.

That seems like pretty weak sauce.

If your sensors can distinguish a Vespa from a sports bike reliably, compared to all the other things that an autonomous vehicle has to cope with programming it to treat those two as different categories of vehicle shouldn’t be particularly hard.

And really we're talking about mass, right? Which is approximated by size

E.g. bicycle vs motorcycle vs Miata vs BMW 8-series vs Suburban vs tractor-trailer

Because that bounds agility, acceleration, and stopping distance, at least to the precision that it would differ in the next 10 seconds.

> at least to the precision that it would differ in the next 10 seconds.

10 seconds? 10 seconds is an eternity.

Some vehicles of similar size might be more than 1/8th of a mile apart in straight line performance in 10 seconds-- let alone the difference once we've got multidimensional vectors.

Exactly. I was thinking the longest span over which an accident could unfold.

My point is-- vehicle dynamics only make a difference in the very short term, because after like a couple of seconds, vehicles can be almost anywhere relative to you even with low performance.

(But, they can be quite different on the timescale of a second).

it only takes 0.2 seconds to turn a motorcyclist into ground beef

If you can't tell apart a bicycle from a 4-cylinder racing bike, let alone a vespa, that's what happnes. And Tesla can't. It also can't read hand signals given by cyclists. It can't tell apart a donkey and a horse.

I've been saying that vehicle dynamics is useful information in the short term. So if you're trying to argue with me, I don't think you've understood my point.

If your goal was to interject an anti-Tesla offtopic comment to the general discussion of vehicle dynamics, it was unwelcome.

When a Tesla can accelerate to 60 mph in less than 2 seconds, knowing the instantaneous velocity and acceleration is not very meaningful. You really need to be able to predict what the acceleration profile will look like over the next N seconds of your maneuver. Holding the currently perceived velocity and acceleration constant over the next N seconds is one naive way to do that. But the actual set of possible trajectories of the other actor is much larger, and you need to drive more conservatively to account for that.