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Comment by TrainedMonkey | Hacker News Reader

There was almost a second where the woman was clearly visible and yet the car did not attempt to emergency break. I would not expect the vehicle to safely stop, but it could have definitely slowed down and reduce the energy of the collision.

This is not criticism against self-driving tech, I would not expect alert human driver to avoid collision either due to limited reaction time. With technology however, we should be able to do better than humans, particularly when it comes to reaction times. Clearly, there is still a some work to do.

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Do we know the vehicle didn't brake? There's no audio to tell us anything, and a car takes "almost a second" to rock forward on its suspension when reacting to brake input too. FWIW, I think I might see the nose bobbing a bit just before the collision, but honestly can't tell.

I certainly don't think you can say "did not attempt to brake" based on the evidence at hand, basically.

Yes, that was in the original announcement

Literally every other statement of fact in the original police announcement was proven false by this video.

Indeed. Uber was clearly able to spin the early reports about this incident; there is little correspondence between those descriptions and this video. Corruption in Tempe.

The victim had absolutely no business crossing that road like that, but the notion that the fatality was somehow unavoidable is pure bunk.

Individual actors all working within the same values system and responding to the same inputs will produce similar actions. There's no conspiracy or "quid pro quo" corruption here, most likely, merely a corrupt values system. In a place like tempe pedestrians and bicyclists are treated as second class citizens, especially in the case of crashes involving automobiles. In this particular case there is a walkway on the median strip which is purely decorative and marked with signs indicating not to use it, which should tell you how pedestrian hostile the area is.

Here's where the crash took place: https://goo.gl/maps/j6PwGkvJwF52

Yeah, I noticed that too, it's about the most asinine bit of roadway design imaginable other than some sort of chute leading to the rotating knives.

> Do we know the vehicle didn't brake?

Because the nose of the car doesn't go down. Especially in an emergency braking situation the nose of the car will go significantly down, and you would see that in the video.

The video is cut before the impact. I don't think we can judge of what will happen in the last second that is missing.

There definitely isn't a full second missing before impact. Maybe a tenth of a second.

The video is cut as the person is a few feet from being struck by the car. That's not "the last second" that's basically at the point of impact and already much too late

from the interior view it doesnt look like the car braked abrubtly

I think it could have stopped safely. Assuming it has quicker reactions than a human, stopping distance should be around 18 meters. I think it just completely missed her.

Edit: critical typo

that is a bold statement to make from the video information we got, at least in my opinion. I would estimate the speed to be at least 50 km/h which gives 25 m as a very rough estimate for the stopping distance without reaction time. It's probably better than that but not 8 m.

But I do agree that the car doesn't seem to have stopped at all and missed the victim completely.

In 8m, though, it may have been able to brake enough to make the collision survivable.

8m ?! That sounds completely unreasonable to me. The first google hit says it is more like 33m..

http://www.brakingdistances.com/38Mph

Apologies, meant to type 18 meters. That's just for the braking - not including reaction time.

But the point is, she was well within the field of detection at that range.

Sure, what's the swerving distance?

The road was empty, I'd bet most drivers would steer away from a pedestrian on the road if only by sheer reflex.

The formulas and online tables are not really accurate for real world modern cars. Example: https://youtu.be/0zbZweqlZPw?t=1m29s finds an empirical stopping distance of 11 meters at 40 mph. Actually closer to 8 mph than 18 mph!

A driver (I refuse to say "human") would have also swerved.

And an autonomous car that actually worked in theory would be able to swerve safely, since it would have a full knowledge of surrounding obstacles and be able to measure the physics of the car as it was swerving, allowing it to keep in a safe envelope. In my mind, the complete lack of reaction from the car paints this as a total failure on the part of the car.

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