UK driving theory test has a part called Hazard Perception: not reacting on children milling around would be considered a fail.
[0] https://www.safedrivingforlife.info/free-practice-tests/haza...
> No person shall drive a vehicle upon a highway at a speed greater than is reasonable or prudent having due regard for weather, visibility, the traffic on, and the surface and width of, the highway, and in no event at a speed which endangers the safety of persons or property.
The speed limit isn't supposed to be a carte blanche to drive at that speed no matter what; the basic speed law is supposed to "win." In practice, enforcement is a lot more clear cut at the posted speed limit and officers don't want to write tickets that are hard to argue in court.
And at the same time, if you were traveling at some speed and no damage was caused, it's harder to say that persons or property were endangered.
Having an understanding for the density and make up of an obstacle that blew in front of you, because it was just a cardboard box. Seeing how it tumbles lightly through the wind, and forming a complete model of its mass and structure in your mind instantaneously. Recognizing that that flimsy fragment though large will do no damage and doesn’t justify a swerve.
Getting in the mind of a car in front of you, by seeing subtle hints of where the driver is looking down, and recognizing that they’re not fully paying attention. Seeing them sort of inch over because you can tell they want to change lanes, but they’re not quite there yet.
Or in this case, perhaps hearing the sounds of children playing, recognizing that it’s 3:20 PM, and that school is out, other cars, double parked as you mentioned, all screaming instantly to a human driver to be extremely cautious and kids could be jumping out from anywhere.
IMO, the bar should be that the technology is a significant improvement over the average performance of human drivers (which I don't think is that hard), not necessarily perfect.
How many humans drivers would pass it, and what proportion of the time? Even the best drivers do not constantly maintain peak vigilance, because they are human.
> IMO, the bar should be that the technology is a significant improvement over the average performance of human drivers (which I don't think is that hard), not necessarily perfect.
In practice, this isn't reasonable, because "hey we're slightly better than a population that includes the drunks, the inattentive, and the infirm" is not going to win public trust. And, of course, a system that is barely better than average humans might worsen safety, if it ends up replacing driving by those who would normally drive especially safe.
I think "better than the average performance of a 75th or 90th percentile human driver" might be a good way to look at things.
It's going to be a weird thing, because odds are the distribution of accidents that do happen won't look much like human ones. It will have superhuman saves (like that scooter one), but it will also crash in situations that we can't really picture humans doing.
I'm reminded of airbags; even first generation airbags made things much safer overall, but they occasionally decapitated a short person or child in a 5MPH parking lot fender bender. This was hard for the public to stomach, and if it's your kid who is internally decapitated by the airbag in a small accident, I don't think you'll really accept "it's safer on average to have an airbag!"
Sadly, you're right, but as rational people, we can acknowledge that it should. I care about reducing injuries and deaths, and the %tile of human performance needed for that is probably something like 30%ile. It's definitely well below 75%ile.
> > And, of course, a system that is barely better than average humans might worsen safety, if it ends up replacing driving by those who would normally drive especially safe.
It's only if you get the habitually drunk (a group that is overall impoverished), the very old, etc, to ride Waymo that you reap this benefit. And they're probably not early adopters.
You also solve for people texting (or otherwise using their phones) while driving, which is pretty common among young, tech-adopting people.
Yes, but the drivers who are 5th percentile drivers who cause a huge share of the most severe accidents are "special" in various ways. Most of them are probably not autonomy early adopters.
The guy who decided to drive on the wrong side of a double yellow on a windy mountain road and hit our family car in a probable suicide attempt was not going to replace that trip with Waymo.
Then you said, "this isn't reasonable", and the bar shouldn't be "slightly better" or "barely better". It should be at least better than the 75th percentile driver.
It sounds like you either misread the parent comment or you're phrasing your response as disagreement despite proposing roughly the same thing as the parent comment.
A 20% lower fatal crash rate compared to the average might be a significant improvement-- from a public health standpoint, this is huge if you could reduce traffic deaths by 20%.
But if you don't get the worst drivers to replace their driving with autonomous, that "20% less than average" might actually make things worse. That's my point. The bar has to be pretty dang high to be sure that you will actually make things better.
Hey, I'd agree with this-- and it's worth noting that 17^2 - 5^2 > 16^2, so even 1MPH slower would likely have resulted in no contact in this scenario.
But, I'd say the majority of the time it's OK to pass an elementary school at 20-25MPH. Anything carries a certain level of risk, of course. So we really need to know more about the situation to judge the Waymo's speed. I will say that generally Waymo seems to be on the conservative end in the scenarios I've seen.
(My back of napkin math says an attentive human driver going at 12MPH would hit the pedestrian at the same speed if what we've been told is accurate).
There are definitely times and situation where the right speed is 7MPH and even that feels "fast", though, too.
Only with instant reaction time and linear deceleration.
Neither of those are the case. It takes time for even a Waymo to recognize a dangerous situation and apply the brake and deceleration of vehicles is not actually linear.
Reaction time makes the math even better here. You travel v1 * reaction_time no matter what, before entering the deceleration regime. So if v1 gets smaller, you get to spend a greater proportion of time in the deceleration regime.
> linear deceleration.
After reaction time, stopping distance is pretty close to n^2. There's weird effects at high speed (contribution from drag) and at very low speed, but they have pretty modest contributions.
Without that these vehicles could only start braking when certainty crossed some arbitrary threshold.
In any case, with zero reaction time, linear deceleration time to stop is proportional to velocity squared. With reaction time, the linear deceleration time is that plus the velocity times the reaction time.
so the two cases we're comparing are 17 * r + (17^2 - 5^2) vs. 16 * r + (16^2), or 17 * r + 264 vs 16 * r + 256. As long as reaction time isn't negative, a vehicle that could slow to 5MPH starting at 17MPH could slow to 0MPH starting at 16MPH.
(There are weird things that happen at <2.5MPH reducing deceleration to sublinear, but the car moves only a few inches at these speeds during a panic stop).
Edit: Not 'allowed' but people do it constantly. Regular drivers, delivery drivers, city workers, construction trucks, etc. There may be laws but very little enforcement.
I would not race at 17 MPH through such an area. Of course, Waymo will find a way to describe themselves as the heroes of this situation.