Waymo robotaxi hits a child near an elementary school in Santa Monica • Hacker News Board

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#711

Post by jjav » Fri, Jan 30, 2026, 10:08 AM UTC

rdtsc wrote: post #642

somenameforme wrote: post #622

Earlier quoted context omitted.

You're omitting the context provided by the article. This wasn't just a random scenario. Not only was this by an elementary school, but during school drop off hours, with both children and doubled parked cars in the vicinity. If somebody doesn't know what double parking is - it's when cars parallel park beside one another, implicitly on the road, making it difficult to see what's beyond them. So you are around young…

That's my thinking as well. Taken in some abstract scenario, all those steps seems very reasonable, and in that abstract scenario we can even say it would do better than an average human would. But that is missing the overall context that this was an elementary school during drop-off hours. That's when you crawl at 3 mph expecting kids to jump behind any car, and not going at 17mph.

> But that is missing the overall context that this was an elementary school during drop-off hours. That's when you crawl at 3 mph expecting kids to jump behind any car, and not going at 17mph.

Indeed. Sure the car knows the limit, it knows it is a school zone, it can precisely track people within the reach of its sensors (but not behind blockages it can't see through).

But it is missing the human understanding of the situation. Does it know that tiny humans behave far more erratically then the big ones? Obvious to us humans, but does the car take that into account? Does it consider that in such a situation, it is likely that a kid that its sensors can't possibly detect has a high probability to suddenly dart out from behind an obstacle? Again obvious to us humans because we understand kids, but does the car know?

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#712

Post by belorn » Fri, Jan 30, 2026, 10:09 AM UTC

expressadmin wrote: post #617

belorn wrote: post #469

Earlier quoted context omitted.

If you drive in Sweden you will occasionally come up to a form of speed reduction strategy that may seem counterintuitive. They all add to make driving harder and feel more dangerous in order to force attention and lower speed. One is to merge opposite directional roads into a single lane, forcing drivers to cooperate and take turn to pass it, one car at a time. For a combined car and pedestrian road (max speed of 7k…

I recently visited a friend that lives in Sweden (couple hours south of Stockholm). Something he said while I visited stuck with me: "Sweden hates cars." There must be a happy medium somewhere in between.

I would say it depend on where you are. City driving is generally not a great experience and its not that uncommon to see a speed bump before almost every crossing, to the point where you get surprised if there isn't one. That said, as long you don't leave the designated main roads that goes through the city areas it is not that bad. They do demand a lot of attention.

Street parking has mostly been turned into exclusive residential parking, so parking houses are often the only choice. As a result they are quite expensive, and you got to walk to the destination.

Parking and access is much better in the country side, and the highways are fairly good and similar to those found in the west Europe. It not as straight or wide as authobahn, but not as much traffic either.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#713

Post by jjav » Fri, Jan 30, 2026, 10:15 AM UTC

missinglugnut wrote: post #608

datsci_est_2015 wrote: post #600

Earlier quoted context omitted.

What an American framing. My convenience at the cost of your eventual safety. I guess this is why we also have toddler death machines with 5-foot grills that we call “full size” vehicles.

If you've ever driven more than 5 miles an hour, you risked hurting someone for your convenience. Acknowledging life has risk tradeoffs doesn't make you an American, but denying it can make you a self-righteous jerk.

> If you've ever driven more than 5 miles an hour, you risked hurting someone for your convenience.

Taken literally, that's clearly not true.

For example you can easily drive 150mph in the flat desert where there is nothing for a hundred miles and you can see many miles ahead. You have zero risk of hurting anyone else unless they somehow teleport in front of you.

But driving 5mph in tight street full of elementary school kids running around can be extremely dangerous.

It's all about context.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#714

Post by Grisu_FTP » Fri, Jan 30, 2026, 10:21 AM UTC

IshKebab wrote: post #706

somenameforme wrote: post #622

Earlier quoted context omitted.

You're omitting the context provided by the article. This wasn't just a random scenario. Not only was this by an elementary school, but during school drop off hours, with both children and doubled parked cars in the vicinity. If somebody doesn't know what double parking is - it's when cars parallel park beside one another, implicitly on the road, making it difficult to see what's beyond them. So you are around young…

> not something a human would typically do lol I'm guessing you don't have kids. This is hilarious.

The full text says: "because driving 17mph (27kph for metric types) in this context is reckless and not something human would typically do"

While i dont have kids, i guess you dont either. Because usually kids dont drive cars, atleast i didnt when i was in elementary school.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#715

Post by jjav » Fri, Jan 30, 2026, 10:28 AM UTC

mattlondon wrote: post #540

lmm wrote: post #535

Earlier quoted context omitted.

> Does it actually work though? Yes. They have made steady progress over the previous decades to the point where they can now have years with zero road fatalities. > And putting obstacles in the road so you cant see if someone is there? That sounds really dangerous and exactly the sort of thing that caused the accident in the story here. Counterintuitive perhaps, but it's what works. Humans adjust their behaviour to…

I think the humans in London at least do not adjust their behaviour for the perceived risk! From experience they will adjust their behaviour to reduce their total travel time as much as possible (i.e. speed to "make up" for lost time waiting etc) and/or "win" against other drivers. I guess it is a cultural thing. But I cannot agree that making it harder to see people in the road is going to make anything safer. Even…

> I think the humans in London at least do not adjust their behaviour for the perceived risk!

Sure they do, all humans do. Nobody wants to get hurt and nobody wants to hurt anyone else.

(Yes there are few exceptions, people with mental disorders that I'm not qualified to diagnose; but vast majority of normal humans don't.)

Humans are extremely good at moderating behavior to perceived risk, thank evolution for that.

(This is what self-driving cars lack; machines have no fear of preservation)

The key part is perceived though. This is why building the road to match the level of true risk works so well. No need for artificial speed limits or policing, if people perceive the risk is what it truly is, people adjust instictively.

This is why it is terrible to build wide 4 lane avenues right next to schools for example.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#716

Post by jjav » Fri, Jan 30, 2026, 10:36 AM UTC

robotresearcher wrote: post #590

jjav wrote: post #398

Earlier quoted context omitted.

There aren't infinitely many scenarios to consider, but even if that's a figure of speech, there aren't thousands or even hundreds. If there's ten kids nearby, that's basically ten path scenarios, and that might be reduced if you have great visibility into some of them. > My brain might be able to quickly assess a handful, but certainly not all. What would you do if you can't assess all of them? Just keep driving sam…

> here aren't infinitely many scenarios to consider, but even if that's a figure of speech, there aren't thousands or even hundreds. There are a very, very large number of scenarios. Every single possible different state the robot can perceive, and every possible near future they can be projected to. Ten kids is not 10 path scenarios. Every kid could do a vast number of different things, and each additional kid raise…

> Ten kids is not 10 path scenarios. Every kid could do a vast number of different things, and each additional kid raises the number of joint states to another power.

This is the difference between computing and humans. The car will attempt to compute all possible path scenarios because it has no instict, and it might not be possible to compute everything in real time so it might fail.

But the human will easily deal with the situation.

Try running through a sports field in an elementary school during lunch, full of unpredictable kids running around. Can you make it from one side to the other without crashing into a whole bunch of kids? Of course you can. You didn't need to try to compute an exponential number of scenarios, you just do it easily. The human brain is pretty amazing.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#717

Post by shaky-carrousel » Fri, Jan 30, 2026, 10:36 AM UTC

ahahahahah wrote: post #241

shaky-carrousel wrote: post #232

Earlier quoted context omitted.

A fully attentive human would've known he was near a school and wouldn't have been driving at 17 mph to begin with.

You clearly don't spend much time around a school measuring the speed of cars. Head on down and see for yourself how often or not a human driver goes >17mph in such a situation.

I said "a fully attentive human". At the very least try to understand my comment before spouting the usual HN snarky reply.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#718

Post by shaky-carrousel » Fri, Jan 30, 2026, 10:37 AM UTC

jobs_throwaway wrote: post #293

shaky-carrousel wrote: post #232

Earlier quoted context omitted.

A fully attentive human would've known he was near a school and wouldn't have been driving at 17 mph to begin with.

Doubt

I said "fully attentive human", not "walking plant".

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#719

Post by Zopieux » Fri, Jan 30, 2026, 10:44 AM UTC

luses wrote: post #569

Zopieux wrote: post #274

Cheers to cities pedestrianizing school streets even in busy capitals (e.g. Paris). Cars have no place near school entrances. Fix your urbanism and public transportation. Yes, kids in developed countries have the autonomy to go to school by themselves from a very young age, provided the correct mindset and a safe environment. That's a combination of: * high-trust society: commuting alone or in a small group is the no…

you're exactly right. the fixation on human vs AV error rates completely misses the point. even if we achieve 'perfect' AVs, mixing heavy machinery with children guarantees conflict. physics dictate cars can't stop instantly. the only solution is removing cars, not better drivers. most commenters here are ignoring the structural incentives. the long term threat of waymo isn't safety, its the enclosure of public infra…

Yup, nailed it.

Re: Waymo robotaxi hits a child near an elementary school in Santa Monica

#720

Post by jjav » Fri, Jan 30, 2026, 10:45 AM UTC

supern0va wrote: post #475

linsomniac wrote: post #445

Earlier quoted context omitted.

>It was going 17 mph. That is rather slow. There's a case to be made that it wasn't slow enough.

I have a hard time believing that a human driver would be as slow as this Waymo, or even slower. I drive my kid to school where it's posted 20mph and there are cameras (with plenty of warnings about the presence of said cameras) and witness a constant string of flashes from the camera nailing people for speeding through there.

Hardcoded limits are problematic because they completely lack context.

On that very same road with a 20mph limit, 40mph might be completely safe or 3mph might be extremely negligently dangerous. It all depends on what is going on in the area.