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Comment by osrec | Hacker News Reader

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

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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!

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.

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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