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Comment by dzdt | Hacker News Reader

Yes, the report you'd hope to be hearing from Uber is along the lines of "0.2 seconds after the pedestrian entered the travel lane the automated system identified her as a hazard and initiated an avoidance maneuver. Despite braking and beginning to swerve away, the car impacted the pedestrian 1.2 seconds later." Thats the promise the automated vehicle people are selling. But in this case it seems the car was clueless.

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If the woman suddenly walked in front of the car at the last minute, I don't see how the situation could have been avoided, no matter how fast a computer is able to process the information from the sensors.

There was also a driver behind the wheel, so it would suggest that humans are just as clueless.

But, ideally, the machinery should be much, much faster at becoming less clueless than the human driver; as the parent said, the ideal is that it should successfully identify, and fail to resolve, the impossible situation.

It should not have no awareness it's in an impossible situation (because that implies it will have no awareness is similar, possible, situations)

”If the woman suddenly walked in front of the car at the last minute, I don't see how the situation could have been avoided”

Likely, but not necessarily. Depending (hugely!) on what actually happened, it might be that the car should have started slowing down before the woman changed course.

As an extreme example, if you’re driving at 50 mph and come up behind a kid cycling at the side of the road with a foot separation between the extrapolated trajectories of the bike and your car, should it be OK to continue your course at full speed, or should drivers take into account that kids are kids, and may move erratically?

Also (again purely hypothetical), if the car had already had several similar events on that road that resulted in near misses, should it have slowed down before it even entered the street, knowing the road segment to be particularly dangerous?

I think human drivers, even though they are horrible at attending to the road for extended periods, get into accidents relatively rarely because they know when they really need to pay attention.

Finally, I do not rule out that that “driver behind the wheel” reacted slower than would have happened if (s)he was actually driving the car.

Disclaimer: I’m a layman, and haven’t seen the video ⇒ Let’s wait and see what the NTSB will say about this.

or that at 50mph, a foot away, you're likely to blow the cyclist over ....

There definitely exists a sort of pre-cognitive human quality to traffic.

Sometimes you just slow down on a subconscious hunch without any information on that particular situation. Or you might be very conscious not to slow down if you're driving a motorcycle in Asia in heavy traffic trying to make a turn with a huge truck barreling behind you.

There are massive differences in road cultures between countries, and it takes a while to adjust to local habits. Somebody who doesn't know these invisible rules is a very accident prone driver even if they can drive safely in another country.

This is a really great point. I wonder if at some point self driving cars will be taught with these regional anomalies in mind. And will they be activated/changed depending on where the car is shipped/activated (Asia vs. America)?

Apart from regional differences, there are a host of other, similar matters. Cruising through your city's bar district at 3am? I'm sure you'll drive more defensively and be prepared for erratic behaviour on the part of others.

However, one thing that I haven't seen discussed anywhere, but that strikes me as a hard problem: by having a non-human driver, you're literally taking out the human element of communication.

Everybody is taught about the importance of eye contact in driver's ed. What will we replace it with? I have no clue, and I doubt anyone else does. Yet it's a crucial technique we all use to negotiate traffic every day, regardless of our mode of transportation.

This is a hard problem, and it's less technical than cultural. It will be a bitch to solve.

Eye contact is another thing that doesn't apply in some Asian countries where by default everyone has dark tinted windows making it virtually impossible to see inside other vehicles.

> some Asian countries where by default everyone has dark tinted windows making it virtually impossible to see inside other vehicles.

Hmm. Perhaps. Personally, I've never noticed this.

Anyway, the concrete example doesn't matter.

I guess you know what I was trying to say: implicit communication between humans. Even without eye contact, there will be a host of minuscule actions (or inactions) that we use to convey intent. There will always be humans on roads, e.g. as pedestrians. Vehicles will be forced to interact with them, and this communication barrier makes it very difficult.

Don't think of highways, think of supermarket parking lots.

Well actually the parking lots are especially difficult due to lack of eye contact.

But I get your point.

People compensate by being very careful when parking and of course you can always roll down your window if the situation requires it.

A robotic vechile simply couldn't manage here. There are way too many dynamic human exceptions. For example, it's common to drive against traffic on the wrong side of the road for short distances since the intersections are so far apart.

It's referred to in the motorcycle community as 'Spidey Sense' - the way your subconscious picks up dangerous situations before you consciously become aware of them, giving you a chance to slow down and become more vigilant.

That’s just human intuition, which is trained over time through experience. Which is also how machine learning works, so it’s not quite clear that humans have a sustainable advantage here.

Well actually we have not proven that ML works the same way, or proven that our ML has the same input parameters as a human yet have we?

Machine learning also has tendency to unlearn things and corrupt it's own models when left unaided.

So do people ;)

A couple of personal examples.

1. I've noticed that adaptive cruise control doesn't account for vehicles entering my lane in front me, even with their turn signal on. As a human driver, I see them entering and know to slow down (at least take my foot off the gas), but the system only performs a hard brake AFTER the car has actually moved into my lane. Disclaimer: I don't know if autopilot systems suffer from the same limitation.

2. I was once waiting to make a protected left turn at a busy intersection. There were two protected left turn lanes, and I was in the farther left lane. Light turns green, I take my foot off the brake, and prepare to accelerate. The car on my right, in the other left turn lane, is also barely starting to move forward, when it suddenly rocks to a halt, indicating they applied the brake, hard. Without thinking, I also brake hard. Out of nowhere, a car appears speeding right through where I would have been if I hadn't stopped. Apparently, this car was entering the intersection on the cross street, going right to left. He wanted to beat the red light (he didn't), and also make his left turn, right down my street, in the opposite direction I was headed. I guess he didn't realize there were two left turn lanes. I never saw him. If I hadn't gone with the herd instinct and hit the brakes, I'm sure there would have been a serious impact. I wonder if autopilot would have caught that one, but it probably depends on camera placement.

A single self driving car probably wouldn't (might do the same thing you did at best).

It'll take actual inter-vehicle communication to extend the sensor-net. Much like humans presently do via proxying though the other car's deviations from anticipated behavior. (EG if the freeway traffic keeps going at proper speed around corners)

I have had vehicles blow by me on a bicycle at 50 mph, on fairly narrow county roads.

Same here during my road biking years (I switched to Jogging and unicycle). Even though I disliked the risk, I enjoyed the wind as it allowed me to ride faster.

I think the parent commenter to your comment was alluding to this kind of stuff, a lack of depth in fallback strategies and systems trained to focus on objects in motion over stationary ones.

https://www.theatlantic.com/technology/archive/2018/03/uber-...

If I was driving a car and saw the pedestrian ahead of time walking or trying to cross I would have slowed down and changed lanes away fro them or at least moved far right if safe. Same thing when you pass bicycles. Change lanes away if possible or at the very least give more buffer. You can never tell what someone may do so you should anticipate the unexpected.

Yep, after a friend had someone try to use her van to commit suicide I am paranoid and get ready to avoid every pedestrian. I don't know what I'd do if I lived somewhere with many pedestrians.

You should be paranoid about pedestrians it turns out, even if they aren’t suicidal. You are in a pedestrian-killing machine, after all. Being paranoid about this is no less reasonable than being sure to keep your chemicals and sharp knives out of the reach of toddlers if you have them both in your home.

I haven't read the words "defensive driving" in any of the articles about this incident.

Yes, and they thought it was a good idea to make cars go at 38mph in a 30mph zone.

Edit: The limit seems to be 35mph sorry, thank all of you for pointing that out. (38 is still over the limit, why allow a robot to do that?)

It was a 35 mph zone.

Are you sure? Per Street View, there's a 45 mph sign where the road goes under the underpass, prior to the site of the accident. Unless that's since changed, of course.

Another possibility: the car was relying on outdated speed limit data. Which is another potential failing of such systems.

"The vehicle was doing about 40 miles per hour on a street with a 45 m.p.h. speed limit when it struck Ms. Herzberg, who was walking her bicycle across the street, according to the Tempe police"

> "The vehicle was doing about 40 miles per hour on a street with a 45 m.p.h. speed limit when it struck Ms. Herzberg, who was walking her bicycle across the street, according to the Tempe police"

According to the article page that you are commenting, "The speed limit where the accident occurred is 35 mph, police spokeswoman Lily Duran said."

Even so, defensive driving is more than simply driving the speed limit. Also from this article, "... the lack of braking or swerving whatsoever is alarming and suggests that the system never anticipated the collision."

Might be an error? If you travel that road on street view, you see a sign for 30mph, the 35mph before the bridge over water, then 45mph at the underpass. The sign is mounted above the road, on the underpass itself.

Of course, something might have changed since street view went through.

This article said 35mph. Other articles have suggested it was a 45mph zone.

On Google Streetview, you can see that the road changes from 35mph to 45mph at the underpass before the site of the accident.

The human in the car said that the first sign they got of a potential issue was the sound of the collision itself. Unless they were paying no attention, that might indicate that this scenario was likely to be very difficult to avoid?

Humans are terrible at remembering specific events, particularly after something so traumatic as hitting and killing a pedestrian. And given that a woman was killed, driver inattention doesn’t seem at all unlikely.

This is an absolutely terrible idea. Don't do this. Your job as traffic is to be as predictable as possible. You're just going to cause more accidents by driving erratically.

The woman cannot go from being "not in path" to "in path" instantaneously unless you believe in teleportation. Supposing the woman got about 1 foot into the path of the car before being struck, the car would have had a minimum of 1 ft / <woman's speed in ft/s> seconds to react, assuming total blindness until the woman was "in path" (I can't think of a real world scenario where this assumption would be strictly true). Suppose a speed of 12 ft/s (~8mph), the car would have had a minimum of 8/100ths of a second to react. Supposing 3 ft of visibility before in path (about the distance from edge of car to lane), the car would have a minimum of ~1/3 second to react. That's assuming the woman was biking along at a good clip already, which is unlikely given that she was crossing a road. So, in all likelihood, the car had over 1/3 of a second to do something. That's just above the typical reaction time of a human (~1/4 second), but I don't think it's an unreasonable expectation for an autonomous vehicle.

I don't see how this is at all accurate without taking to account the speed of that car. If human reaction time is 1/4th of a second, how time does that actually leave for the car move as well - the car can't teleport either.

We know the car was going roughly 40mph, so that puts some constraints on the minimum response time that was available. Unless this woman literally catapulted in front of the car, there were at least 4’ of lateral walking pace worth of 40mph time to react. You do need to make assumptions about how fast she was moving, of course, and as has been noted elsewhere in the thread you have to assume that the driver was in the left lane for this scenario to even be remotely plausible. Even in this sequence, the car should have been able to substantially decelerate but, looking at the pictures, that doesn’t seem to have happened.

An accident might have been unavoidable, but fatality is the big question. The risk of pedestrian fatality jumps by ~4x between 30mph and 40mph.[0] So the question is - did the car start breaking as soon as possible?

As an aside, that statistic is why I never speed in pedestrian zones.

https://nacto.org/docs/usdg/relationship_between_speed_risk_...

> did the car start breaking as soon as possible?

“braking”; “breaking” is something else, and not a desirable response.

"breaking" implies it was "working" in the first place.

Based on the NTSB pictures of the vehicle as well as police statements, it doesn’t seem that the vehicle tried to brake.

The fact that in most cases the human has to do nothing means that it is unlikely that the human is anywhere close to being as vigilante as an actual human driver. The fact that the human is clueless isn't surprising at all. In fact this is the real danger with systems like Tesla's autopilot. You still ned to be vigilante, but you are so bored that it is hard to be.

The safety humans here might as well be hood ornaments.

The word you're looking for is "vigilant". "Vigilante" means "a member of a self-appointed group of citizens who undertake law enforcement in their community without legal authority, typically because the legal agencies are thought to be inadequate".

Correct. I also meant “need” and not “ned”.

If the woman suddenly walked in front of the car at the last minute, I don't see how the situation could have been avoided

From /r/roadcam yesterday: https://www.youtube.com/watch?v=wYvKPMaz9rI

Human driver avoided hitting the pedestrian. There are lots of videos of human drivers successfully not hitting people who "suddenly" pop out "at the last minute". Self-driving cars should be able to match that. If they can't, they don't belong on public roads yet.

I'm really skeptical about swerving as an evasive maneuver. It's complicated to get that right. But yes, if it didn't at least slam the brakes then something went badly wrong.

Maybe you can't prevent an accident, but you can at least reduce momentum and demonstrate that your system was working correctly.

Why didn't the human hit the brake? I don't understand how this is even news to be honest. There was a human in the driving seat and he failed to stop just like the computer.

Computers have better reaction times than humans. Forcibly braking is a simple maneuver.

> Computers have better reaction times than humans. Forcibly braking is a simple maneuver.

The question isn't about the MHZ speed of a computer or the theoretical reaction time but the lack of reaction by the computer in the actual real world. It doesn't matter if this is a sensor failure, a software bug, or a slow reaction by a computer. The result is the same. A person died.

From the article:

*"... the lack of braking or swerving whatsoever is alarming and suggests that the system never anticipated the collision.”

Probably the human wasn't paying close attention. That is the problem with level 3-4 automated vehicles: a human who is not in primary control of the vehicle has trouble paying attention and is unable to take over control quickly if it is needed.

Wait, are you now blaming level 3-4 automated vehicles for the inattention of the human?

It’s a problem people knew about back when “autopilot” was just for aircraft, not cars.

https://blog.prototypr.io/automation-is-making-us-dumber-and...

Ultimately, we have to design systems for the humans that actually exist, not some hypothetical superhuman. If it's not safe for actual humans to use then it's not safe full stop. It's not like this is some new issue; it's one of the main reasons why experts have been pessimistic about the prospects of self-driving cars and why existing car companies have been reluctant to deploy heavy automation in the field.

I think he's blaming the folks who put level 3-4 vehicles on the road presumably knowing full well that said human inattention would put people at serious risk of injury and death in the car's edge cases.

That's why I think vehicle automation development follow the path where the computer is not in primary control of the vehicle and can take over quickly when needed. Unlike humans, computers don't have trouble paying attention.

You can (and should!) brake and swerve at the same time. Unless you are driving an oldtimer, the car is capable of doing that.

In my driving lessons I got told to swerve for humans. Pedestrians and cyclists are the least protected participants in traffic. If you swerve and hit another car, the resulting crash will cause a lot of damage, but injuries to humans will likely be much less severe, if they even happen.

Animals, especially small ones are a different matter. Using the same argument, it is better to risk hitting the animal than risking sverving into other traffic.

Yes and no. The very action of braking will reduce available grip for the swerve. However, ABS and stability control mean you are at least quite unlikely to lose control if you try to do both at the same time. And of course, in this case, only a mild swerve would have been required, and adding braking would help scrub speed in the event that the obstacle moves in a manner that your swerve does not avoid.

There are so many variable here. If you are travelling at 30kmph and swerve into the path of a car going the opposite direction at 80kmph, that's a massive crash.

Swerving is a better way to avoid a collision, but braking would have at least reduced the severity.

Of course, this all presumes you can quickly analyze the situation and conclude that it is safe to swerve (which, in theory, the computer can do far faster than a human can).

Even the reaction is within 0.1s for the machine, you cannot brake and stop immediately. This is physics, and a mechanical problems.

Please remove the software mindset when looking into this.

The car can begin to brake right away, and must certainly be expected to have a faster reaction time than a human. Whether it started to brake seems like the most important question here.

Not in the field but I am assuming that the AI/ML cannot handle the ability to see possible road hazards with in the human peripheral vision area

Such as a kid attempting to chase down a ball that is rolling towards the road (object vector path collision), specially with the ball and or kid suddenly hidden from view because of a parked car (real environment vs visual environment). Or a group playing basketball in a driveway. Both where slowing down is always the safer bet.

Sure, but I don't think you can expect that kind of information the next day or even the next month.

Someone is dead and there may well be one or more trials as a result. Facts will take a s long as they take to surface.

As was the driver, mind you

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