Comment by amluto

Comment by amluto 2 days ago

Waymo’s performance, once the pedestrian was revealed, sounds pretty good. But is 17mph a safe speed at an active school dropoff area? I admit that I don’t think I ever personally pay attention to the speedometer in such a place, but 17mph seems excessive even for an ordinary parking lot.

I wonder whether Waymo’s model notices that small children are present or likely to be present and that it should leave extra margin for error.

(My general impression observing Waymo vehicles is that they’ve gone from being obnoxiously cautious to often rather aggressive.)

izacus 6 hours ago

I bet most drivers plow through that area at 30mph (since it's 25mph limit) instead if driving as slow as 16.

Even people being all indignant on HN.

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aanet 2 days ago

> But is 17mph a safe speed at an active school dropoff area?

Now you're asking interesting questions... Technically, in CA, the speed limit in school zones are 25 mph (which local authorities can change to 15 mph, as needed). In this case, that would be something the investigation would check, of course. But regardless of that, 17 mph per se is not a very fast speed (my gut check: turning around intersections at > 10-11 mph feels fast, but going straight at 15-20 mph doesnt feel fast; YMMV). But more generally, in the presence of child VRUs (vulnerable road users), it is prudent to drive slowly just because of the randomness factor (children being the most unaware of critters). Did the Waymo see the kids around in the area? If so, how many and where? and how/where were they running/moving to? All of that is investigation data...

My 2c is that Waymo already took all of that into account and concluded that 17 mph was indeed a good speed to move at...

...which leads to your observation below:

> (My general impression observing Waymo vehicles is that they’ve gone from being obnoxiously cautious to often rather aggressive.)

Yes, I have indeed made that same observation. The Waymos of 2 years ago were very cautious; now they seem much more assertive, even a bit aggressive (though that would be tough to define). That is a driving policy decision (cautious vs assertive vs aggressive).

One could argue if indeed 17 mph was the "right" decision. My gut feel is Waymo will argue that (but likely they might make the driving policy more cautious esp in presence of VRUs, and child VRUs particularly)

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veltas 2 days ago

> Technically, in CA, the speed limit in school zones are 25 mph
Legally a speed limit is a 'limit' on speed, not a suggested or safe speed. So it's never valid to argue legally that you were driving under the limit, the standard is that you slow down or give more room for places like a school drop-off while kids are being dropped off or picked up.

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- franktankbank 2 days ago
  
  Yep, if I plow into stationary vehicles on the highway while going the "limit" that's not a very solid defense is it?
  
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  aanet 2 days ago
  
  > Yep, if I plow into stationary vehicles on the highway while going the "limit" that's not a very solid defense is it?
  Well, people are doing a lot of what-about-ism in this situation. Some of that is warranted, but I'd posit that analyzing one "part" of this scenario in isolation is not helpful, nor is this the way Waymo will go about analyzing this scenario with their tech teams.
  Let's consider, for argument's sake, if the Waymo bot had indeed slammed at the brakes with max decel, and had come to a complete (and sudden) stop barely 5cm in front of the kid. Would THAT be considered a safe response??
  If I'm a regulator, I'd still ding the bot with an "unsafe response" ticket and send that report to Waymo. If YOU were that pedestrian, you'd feel unsafe too. (I definitely have seen such responses in my AV testing experience). One could argue, again, that that woulda been legally not-at-fault, but socially that would be completely unacceptable (as one would guess rightly).
  And so it is.
  The full behavior sequence is in question: When did Waymo see the kid(s), where+ how were they moving, how did it predict (or fail to) where they will move in the next 2s, etc. etc. The entire sequence -- from perception to motion prediction to planning to control -- will be evaluated to understand where the failure for a proper response may have occurred.
  As I mentioned earlier, the proper response is, under ideal conditions, one that would have caused the vehicle to stop at a safe distance from the VRU (0.5m-1m, ideally). Failing which, to reduce the kinetic energy to a minimum possible ("min expected response")... which may still imply a "contact" (=collision) but at reduced momentum, to minimize the chance of damage.
  I suspect (though I dont know for sure) that Waymo executed the minimum expected response, and that likely was due to the driving policy.
  We won't know until we see the full sequence from inside the Waymo. Everything else is speculation.
  [Disclaimer: I dont work for Waymo; no affiliation, etc etc]
  
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