Comment by BugsJustFindMe

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.

"I'd love to see video of the incident because driving 17mph (27kph for metric types) in this context is reckless and not something human would typically do"

I am not sure what your definition of typical is. The reason we have lower speed zones in school districts at specific times is because humans typically drive fast. The reason police officers frequently target these areas and write a plethora of tickets is because humans typically ignore speed limits.

Your claim seems to be that a human would drive much slower than the posted speed limit considering the conditions, but the laws and the court room suggest otherwise.

>driving 17mph (27kph for metric types) in this context is reckless and not something human would typically do

Unfortunately, a vast overestimation of human danger recognition. Or empathy, unsure

Driving is based so much off of feel so my numbers may be off, but in the scenario you are talking about 5mph seems reasonable, 10mph already seems like to much.

> 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

This is not called double parking. Double parking is something different: https://en.wikipedia.org/wiki/Double_parking

I don't know about you but here in the UK, close parallel parking is normal and expected, and I was taught to avoid trying to cross in the gap between two parked cars, and to be extra careful if I was going to. In this scenario some blame might lie with the driver for going too fast, but I would certainly also blame the child (or their parent) for stepping far into the road without looking.

30kph is the posted speed limit in school zones here, precisely because it's an appropriately slow speed for the context.

While I completely agree with your premise, the software can be improved. It can be programmed to drop down to 5 miles an hour or less depending on street size, pedestrian proximity, school zone, etc.

If only the same could be said for the other parents in the school zone. I’ve seen people roar by in similar scenarios at 30+ miles an hour.

> not something a human would typically do

lol I'm guessing you don't have kids. This is hilarious.

As someone who lives on a residential street right by a primary school in the UK, the majority of drivers are going over 20mph even at the peak time when there are children everywhere.

While in theory human drivers should be situationally aware of the higher risks of children being around, the reality is that the majority will be in their own bubble of being late to drop their kid off and searching for the first free spot they can find.

Have you been in a waymo? It knows when there are pedestrians around (it can often see over the top of parked cars) and it is very cautious when there are people near the road and it frequently slows down.

I have no idea what happened here but in my experience of taking waymos in SF, they are very cautious and I'd struggle to imagine them speeding through an area with lots of pedestrians milling around. The fact that it was going 17mph at the time makes me think it was already in "caution mode". Sounds like this was something of a "worst case" scenario and another meter or 2 and it would have stopped in time.

I think with humans, even if the driver is 100% paying attention and eyes were looking in exactly the right place where the child emerged at the right time, there is still reaction times - both in cognition but also physically moving the leg to press the pedal. I suspect that a waymo will out-react a human basically 100% of the time, and apply full braking force within a few 10s of milliseconds and well before a human has even begun to move their leg.

Your opinion of "most humans" is vastly overinflated. The median human driver would be going 5 over the speed limit, on their cell phone, and paying fuck all attention. Humans never drive as slow as 17 mph, even in the context of being directly in front of schools with visible children.

> But most humans would have been aware of the big picture scenario much earlier.

I wouldn't call it likely. Sure, there are definitely human drivers who are better than Waymo, but IME they're few and far between. Much more common to be distracted or careless.

According to the article the car was traveling at 17 miles an hour before it began braking. Presumably this was in a 25 mph school zone, so it seems the Waymo was already doing exactly what you describe - slowing down preemptively.

It was going 17 mph. That is rather slow.

To put it another way. If an autonomous vehicle has a reaction time of 0.3 seconds, the stopping distance from 17 mph is about the same as a fully alert human driver (1 second reaction time) driving 10.33 mph.

In this situation, the car was already driving under the legal speed required for a school zone (25mph when children are present) [edit: some comments in the post suggest there is a 15mph sign, which is sometimes posted; to me, driving 17mph in a 15mph zone is acceptable).

I think any fair evaluation of this (once the data was available) would conclude that Waymo was taking reasonable precautions.

> But most humans would have been aware of the big picture scenario much earlier. Are there muliple kids milling around on the sidewalk? Near a school? Is there a big truck/SUV parked there?

Waymos constantly track pedestrians nearby, you can see it on the status screen if you ride in one. So it would be both better able to find pedestrians and react as soon as one was on a collision course. They have a bit more visibility than humans do due to the sensor placement, so they also can see things that aren't that visible to a person inside the car, not to mention being constantly aware of all 360 degrees.

While I suppose that in theory, a sufficiently paranoid human might outdo the robot, it looks to me like it's already well above the median here.

Curiously enough Google could have access to how fast humans usually drive through that street.. if they record people's Google Maps trips, they can show the court that "Look, 80% of Google Maps users drive through here at 30 mph!".

Two things:

I've read studies saying that most drivers don't brake at max effort, even to avoid a collision. This may be at least one of the reasons that Waymo predicted that an attentive human would likely have been going faster than their car at the moment of impact. I've got a good idea of my fun-car's braking performance, because I drive it hard sometimes, but after reading that I started practicing a bit with my wife's car on the school run, and... Yeah: it's got a lot more braking power than I realized. (Don't worry, I brake hard on a long straight exit ramp, when no one's behind me, a fast slow-down is perfectly safe, and the kiddo loves it.) I've now got an intuitive feel for where the ABS will kick in, and exactly what kind of stopping distance I have to work with, which makes me feel like a safer driver.

Second, going off my experience of hundreds and hundreds of ride-share rides, and maybe thirty Waymo journeys, I'd call the best 10-15% of humans better drivers than Waymo. Like, they're looking further up the road to predict which lane to be in, based on, say, that bus two blocks away. They also drive faster than Waymos do, without a perceptual decrease in safety. (I realize "perceptual" is doing some work in that sentence!) That's the type of defensive and anticipatory urban driver I try to be, so I notice when it's done well. Waymo, though, is flat-out better, in every way, than the vast majority of the ride-share drivers I see. I'm at the point where I'll choose a Waymo any time it'll go where I'm headed. This story reinforces that choice for me.

It would be nice to see the video (although maybe there are some privacy issues, it is at a school after all).

Anyway, from the article,

> According to the NHTSA, the accident occurred “within two blocks” of the elementary school “during normal school drop off hours.” The safety regulator said “there were other children, a crossing guard, and several double-parked vehicles in the vicinity.”

So I mean, it is hard to speculate. Probably Waymo was being reasonably prudent. But we should note that this description isn’t incompatible with being literally in an area where the kids are leaving their parents’ cars (the presence of “several double parked cars brings this to mind). If that’s the case, it might make sense to consider an even-safer mode for active student unloading areas. This seems like the sort of social context that humans might have and cars might be missing.

But things speculation. It would be good to see a video.

> The car only slows down after seeing someone.

How do you know that? The article says it slowed from 17 mph. That’s cautious progress speed, not cruising speed.

> But most humans would have been aware of the big picture scenario much earlier. Are there muliple kids milling around on the sidewalk? Near a school? Is there a big truck/SUV parked there?

Waymos do this and have for years. They know where the people are around them and will take precautionary action based on that.

Here's a video from 2019 of one understanding that a car in the bike lane means the cyclists may dart out into the lane it's in and taking action based on that. https://waymo.com/blog/2019/05/safety-at-waymo-self-driving-...

That video is nearly 7 years old at this point and they've gotten much, much better since then.

If you think a fully-attentive human driver would have done better, I think you're kidding yourself.

I know you didn't make this point, but if anyone think the average LA driver would have done better than this I've got a bridge to sell you and that's really what matters more. (I say that as someone who used to live like half a mile from where this happened)

It was already moving slowly. 17MPH is pretty conservative. Most human drivers going past my local school are doing at least 30.

In principle, attentive drivers, who have either somehow come independently to the appropriate understanding or have been trained in how to react to hazards ahead...

https://www.gov.uk/theory-test/hazard-perception-test

... could in some circumstances know that there's a likelihood that a child will emerge suddenly and reduce their speed in anticipation where circumstances allow.

Note that: If you cut speed but other drivers can't see why they may overtake, even unsafely, because you are a nuisance to them. Slowing in anticipation that a child will run out from behind the SUV, only for a car behind you to accelerate around you and smack straight into the child at even higher speed, is not the desired outcome even though you didn't hurt anybody...

And yes, we'd need to see the video to know. It's like that Sully scenario. In a prepared test skilled pilots were indeed able to divert and land, but Sully wasn't prepared for a test. You're trained to expect engine failure in an aeroplane - it will happen sometimes so you must assume that, but for a jet liner you don't anticipate losing both engines, that doesn't happen. There's "Obviously that child is going in the road" and "Where the fuck did they come from?" and a lot in between and we're unlikely to ever know for sure.

There's a bus stop right behind my house. I routinely hear the driver honking and yelling at people who ignore when the stop sign is extended (which is a misdemeanor in my state). So forgive me for not assuming a human would have done better.

I live in an area where there are pedestrians stepping into the street without looking, all over the place, and you can drive / cycle without hitting them but have to slow down appropriately if you have to go near something that you can't see behind. Like you say it would be interesting to see the video.

I drive like this too, but I think we’re a small minority. Especially here in LA.

The car was driving 17mph before braking. I don’t think I’ve ever seen a human drive at 17mph in a school zone or other area children congregate.

Are they not using a ton of ML to take exactly this sort of context into account?

>The car can react faster that I can after seeing someone

and that can potentially allow internal planning algorithm to choose more risky and aggressive trajectories/behavior, etc. say to reach target destination faster and thus deliver higher satisfaction to the passengers.

Anecdote, but I live next to an elementary school and also on a route frequented by Waymos. Human drivers routinely cruise down the 25mph roads at 40+ and blow stop signs, even during school intake and release. Waymo vehicles always seem a lot more cautious.

When thinking about these things you have to factor in the prior probability that a driver is fully attentive, not just assume they are.

If you’ve ever been in a Waymo you quickly realize their field of view is pretty good. You often see the vehicle sensing small pets and children that are occluded to a passenger or driver. For this reason and my experience with humans near aforementioned school, I doubt a human would out perform the Waymo in this particular incident and it’s debatable they even have more context to inform their decisions.

All that said, despite having many hours in a Waymo, it’s not at all clear to me how they factor in sidewalk context. You get the sense that pedestrians movement vectors are accounted for near intersections, but I can’t say I’ve experienced something like a slow down when throngs of people are about.

Precisely. Environmental context is not considered in Waymo's "peer-reviewed model" (I encourage reflexive commenters to first read it: https://waymo.com/safety/collision-avoidance-benchmarking), only basic driver behavior and traffic signal timings.

Note the weaselly "immediately detected the individual as soon as they began to emerge" in the puff piece from Waymo Comms. No indication that they intend to account for environmental context going forward.

If they already do this, why isn't it factored in the model?

In Bulgaria we have a similar speed reduction strategy but we are a bit ahead of Sweden: We use medium-radius but very deep potholes. If you lose attention for even a split second, you are forced to a full stop to change a tire. Near schools it gets more "advanced": they put parked cars on both sides of the road, and the holes positioned so you can't bypass them. For example, two tire-sized holes on both sides of the road right next to the parked cars. You have to come to a complete stop, then slowly descend into the hole with the front wheels, climb back out, and repeat the process for the rear wheels. Occasionally, even though we (technically) have sidewalks, they are covered in mud or grass or bushes, so pedestrians are forced to walk in the middle of the road. This further reduces driving speed to walking pace and increases safety in our cities. Road markings are missing almost everywhere and they put contradicting road signs so drivers are not only forced to cooperate but also to read each other minds.

It's fairly common at least in the Netherlands, Germany, and Switzerland too. In Switzerland they also place street parking spots on alternating sides on narrow streets, which also makes you more attentive and lower your speed.

I've heard that that is why roundabouts are safer than their alternatives: counterintuitively, they're safer because they're less safe, forcing the user to pay more attention as a result.

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.

why not just put in speedbumps if all you're trying to do is slow people down? Are you sure this was the purpose of these designs? sounds a little too freakonomics to me.

It's a runaway process of prioritizing safety over convenience -- and it's wrecking their road base just before self-driving cars would allow them to have both.

Does it actually work though?

Many roads in London have parked cars on either side so only one can get through - instead of people cooperating you have people fighting, speeding as fast as they can to get through before someone else appears, or race on-coming cars to a gap in the parked cars etc. So when they should be doing 30mph, they are more likely doing 40-45. Especially with EVs you have near-instant power to quickly accelerate to get to a gap first etc.

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.

Madness.

Certainly, I'm not against constructive criticism of Waymo. I just think it's important to consider the counterfactual. You're right too that an especially prudent human driver may have avoided the scenario altogether, and Waymo should strive to be that defensive.

Absolutely, I can tell you right now that many human drivers are probably safer than the Waymo, because they would have slowed down even more and/or stayed further from the parked cars outside a school; they might have even seen the kid earlier in e.g. a reflection than the Waymo could see.

First, it's still the automobile's fault.

At least it was already slowed down to 17 mph to start. Remember that viral video of some Australian in a pickup ragdolling a girl across the road? Most every comment is "well he was going the speed limit no fault for him!" No asshole, you hit someone. It's your fault. He got zero charges and the girl was seriously injured.

I don't see how that's feasible without introducing a lot of friction.

Near my house, almost the entire trip from the freeway to my house is via a single lane with parked cars on the side. I would have to drive 10 MPH the entire way (speed limit is 25, so 2.5x as long).

Aye, and to always look for feet under and by the front wheel of vehicles like that.

Stopped buses similarly, people get off the bus, whip around the front of them and straight into the streets, so many times I’ve spotted someone’s feet under the front before they come around and into the street.

Not to take away from Waymo here, agree with thread sentiment that they seem to have acted exemplary

Yes and no. Tons of situations where this is simply not possible, whole traffic goes full allowed speed next to row of parked cars. If somebody unexpectedly pops up distracted, its a tragedy guaranteed regardless of driver's skills and experience.

In low traffic of course it can be different. But its unrealistic to expect anybody to drive in expectation that behind every single car passed there may be a child jumping right in front of the car. That can be easily thousands of cars, every day, whole life. Impossible.

We don't read about 99.9% of the cases where even semi decent driver can handle it safely, but rare cases make the news.

>reacted after seeing the child step out from behind the SUV.

Lmao most drivers I see on the roads aren't even capable of slowing down for a pedestrian crossing when the view of the second half of the crossing is blocked by traffic (ie they cannot see if someone is about to step out, especially a child).

Humans are utterly terrible drivers.

This is generally the problem with self-driving cars, at least in my experience (Tesla FSD).

They don't look far enough ahead to anticipate what might happen and already put themselves in a position to prepare for that possibility. I'm not sure they benefit from accumulated knowledge? (Maybe Waymo does, that's an interesting question.) I.e., I know that my son's elementary school is around the corner so as I turn I'm already anticipating the school zone (that starts a block away) rather than only detecting it once I've made the turn.

Yes I agree, but why 10mph? Why not 5mph? or 2mph? You'll still hit them if they step out right in front of you and you don't have time to react.

Obviously the distances are different at that speed, but if the person steps out so close that you cannot react in time, you're fucked at any speed.

10mph will do serious damage still, so please for the sake of the children please slow yourself and your daughter's driving down to 0.5mph where there are pedestrians or parked cars.

But seriously I think you'd be more safe to both slow down and also to put more space between the parked cars and your car so that you are not scooting along with a 30cm of clearance - move out and leave lots of space so there is more space for sight-lines for both you and pedestrians.

I appreciate your sensible driving, but here in the UK, roads outside schools are complete mayhem at dropping off/picking up times. Speeding, overtaking, wild manoeuvres to turn round etc.

When reading the article, my first thought was that only going at 17mph was due to it being a robotaxi whereas UK drivers tend to be strongly opposed to 20mph speed limits outside schools.

> especially when I see some obstruction ('behind a tall SUV', was the waymo overtaking?)

Yep. Driving safe isn't just about paying attention to what you can see, but also paying attention to what you can't see. Being always vigilant and aware of things like "I can't see behind that truck."

Honestly I don't think sensor-first approaches are cut out to tackle this; it probably requires something more akin to AGI, to allow inferring possible risks from incomplete or absent data.

> Does Waymo have the same object permanence and trajectory prediction (combined) to that of a human?

On this note specifically ive actually been impressed, ie when driving down Oak st in SF (fast road, tightly parked cars) I've often observed it slow if someone on a scooter on the sidewalk turns to look toward oncoming traffic (as if to start riding), or to slow passing parked box trucks (which block vision of potential pedestrians)

“Does Waymo have the same object permanence and trajectory prediction (combined) to that of a human?”

Good technical question

I live near a school zone in LA and most drivers do not obey school zone speed limits.

You will get honked at by aggro drivers if you slow down to the school zone speed limit of 25mph. Most cars go 40ish.

And ofc a decent chunk of those drivers are on tiktok, tinder, Instagram, etc

Some human drivers? Yes, certainly.

Your median human driver? Sadly, I think not. Most would be rushing, or distracted, or careless.

> waymo is driving recklessly by obeying the speed limit here (assuming it was 20mph) in a way that many humans would not.

I don't think we can say at all that the Waymo was driving recklessly with the data we currently have

So you say, with hindsight. Regardless, what you would do is irrelevant. The question is: what would the ~average driver do? If you tell me the average driver goes <=14mph in that situation, I'm gonna look at you funny.

Could be! In aggregate though, Waymos have shown to be safer than human drivers, so my prior is that that holds here.

People who reflexively assume a human driver would do better

LOL

I do the same, and try to actively anticipate and avoid situations like this. Sadly, in my experience most drivers instead fixate on getting to their destination as fast as possible.

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.

Doubt

If you have contradicting data I'd be glad to see it

>It's likely that a fully-attentive human driver would have done worse.

Is based off the source I gave in my comment, the peer-reviewed model

> a huge portion of human drivers

Is based on my experience and bits of data like 30% of fatal accidents involving alcohol

Like I said, if you have better data I'm glad to see it

Emergency braking in non-camera/non-LIDAR cars requires a significant radar signal which you're only going to get from another vehicle (and even then it's noisy and tends to produce frustrating false positives, leading to later-than-you-want stops). It very likely won't detect a child or a dog, I'm not aware of a single instance of an EBS claiming to have done so in practice (and kids and dogs get hit every day!).