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Comment by tomkarlo | Hacker News Reader

I'd guess that "unknown objects" happen all the time - it seems like that's the default until something is classified, so tire scrap or plastic bag would also fall into that category. If the car slowed down every time it saw one it would never get anywhere, it should only slow if the object gets classified as something you can't hit and is clearly in the path of the vehicle. Seems like that decision happened too late here, requiring emergency braking... which was disabled (!).

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The missing bit here is "...unknown is detected on the road" - if there is a tire scrap or plastic bag or anything that looks suspicious a normal human driver would slow down and give it extra attention, then try to avoid it anyway. You don't drive over / through an object unless you know that it is not harmful, and even then you try to avoid it so you don't drive over a bag... of nails.

It's not that simple. Humans can also predict movement, and that is necessary because cars don't stop instantaneously. So you have a person walking toward the street and your dumb smart car is constantly hitting the brakes.

This tech simply isn't there yet and I doubt it's all that close.

> So you have a person walking toward the street > and your dumb smart car is constantly hitting the brakes.

Doesn't sound dumb to me. The car should be going slow enough to emergency stop if the pedestrian enters the road.

human track gaze and understand desires, so you kinda know if someone exiting a shop will or will not proceed straight into the road.

that said, as I said above whenever a car sense a situation it doesn't understand it should slow down, that's enough to be safe later on as the situation develops and is different than hitting the brakes full force.

and anyway expecting autonomous car to drive full speed all the time is moronic, humans don't do that either, precisely because it's dangerous.

People don't drive like that. People expect reasonable behavior from other people and that includes expectations that they won't jump into the road. If Uber will drive unreasonably, its passengers will prefer other taxi who drive more aggressively.

Except no one drives that way and no one would put up with it. Do you slow down every time someone on the sidewalk takes a step toward the street? I doubt it (and, if you do, please never get in front of me.)

So, yeah: dumb.

If I think they might walk on the street I of course slow down (as much as I deem necessary). What kind of question is that?

If I think I saw children run around between cars on the parking lane, are the parents probably morons? Yes. Do I slow down and be prepare to slam the brakes in case a child suddenly runs in front of me? Ab-so-lute-ly.

Even if people behave idiotically on the street, it is obviously still my fault if I run them over.

>If I think they might walk on the street I of course slow down

And that's what I'm talking about. Computers aren't all that good at determining whether or not a person is going to jump into the street.

  This tech simply isn't there yet and I doubt it's all that close.

In which case it's absolutely criminal by the government of Arizona to allow testing such tech on public roads.

As a human, if I saw a plastic bag blow into the street at night I'd slow down until I was sure it wasn't an animal or something. Seems like basically the same process.

Sure, but if you were on a highway, would you slam on the brakes? I hope not.

There's a calculation here of balancing the perceived risk of an obstruction with the consequences of avoiding it or braking in time. Drivers have to make this decision all the time, on a highway they will generally assume it's safer to hit most things than swerve or panic brake, because it's mostly likely not that dangerous to collide with.

At least one stat I saw from AAA is that ~40% of the deaths from road debris result from drivers swerving to avoid them.

That means 60% result from hitting them.. still seems better to swerve.

How many plastic bags do you have crossing your streets?! Around here I doubt you'd slow down more than a couple of times per month.

Not as many since they banned them here, but it used to be quite common given the combination between the fact it's pretty windy here in SF every afternoon, and there's lots of trash / debris around. It's still pretty common to see blowing paper or other debris (tire shreds) in the road at least a few times in my 12 mile commute.

This has been a not-minor problem for autonomous cars and the Tesla-style autopilots / adaptive cruise controls that depend on vision only. You have to program it to ignore some types of things that seem like they might be an obstruction, such as road signs, debris in the road, etc. so they don't hit the brakes unnecessarily.

> If the car slowed down every time it saw one [unknown object] it would never get anywhere

well tough shit then, a car that plows trough situation it doesn't understand should never be on the public road

Both adaptive cruise controls and human drivers do this by default. If you're doing 60 MPH on a highway and something pops into the periphery of your vision that you don't recognize, do you slam on the brakes? No.

of course I do slow down, there's a whole load of possibilities between slamming the brakes and get rear ended and driving at the posted limit trough a dangerous situation, you know? car can slow down gently.

it's a 60 zone and rain or smoke impairs the visibility? slow down.

it's a 45mph zone and something that's not a motor vehicle is in a lane that's supposed to only have motor vehicles on it? you slow down until you make sense of the situation.

you're near a playground and a mother is walking a children on the other side of the road and you can't see if she's holding his hand? you slow down.

a person walks near the kerb and it's not looking in your direction? you slow down. a bike is loaded with groceries? a car acting erratically? a person being pulled by his dog? a bus stopped unloading people? you don't drive past them at 30mph.

driving safely: super simple stuff.

> super simple stuff

If people did the super simple stuff, we'd have boundless peace, prosperity, liberty.

I remember a story - stop me if you've heard this one - about a God helping out a group of desperate people, freeing them from slavery, parting seas, feeding them in the desert. They were camped at the foot of a mountain with the God right there on top - right there! And they built the golden calf anyway. And that rule seems easier than all the other 9. WTF did they even need a golden calf for?

So sadly, the criteria of simplicity is irrelevant - people will find a hard way to do it.

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