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Comment by andrenotgiant | Hacker News Reader

Imagine you are on the highway in self-driving mode and there's a plastic bag flapping around on the road ahead.

Probably best NOT to stop in that scenario.

It's the millions of "edge cases" that humans are pretty decent about making quick decisions on that make self-driving cars really scary to me.

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Probably best NOT to stop in that scenario.

The car should slow down for that scenario. It doesn't know if the situation is 100% safe, so it should apply the brakes and steer to avoid a collision using data from around the car to determine the safest course. Driving through a hazard is only an option for a self-driving car if there is literally no other option.

Cars are not people and they're not capable of making decisions in the same way people do. They should be taking the safest route all the time.

Driving through a plastic bag also just isn't a safe option in rare cases for cars. It can get wrapped around something and cause some damage or latch onto the exhaust and burn and smell awful.

Do people here really just drive through road hazards without being cautious?

If you brake in the middle of the highway (even just to slow a little) when the road ahead is clear you become a bigger hazard than the plastic bag. Double if you swerve as you suggested.

The road ahead isn't clear though. A self-driving car knows something is there but it doesn't know what it is or what it might mean about potential future events. You and I know a plastic bag is likely to be a one-off non-dangerous thing but a car doesn't (it might know about a person, or a bag, or another car, but it won't recognise all of the things it could be). Consequently it has to be cautious and should take action within the bounds of what is safe using data from around the car.

It should not stop in that scenario because there is no hazard. Wild application of brakes is just as dangerous as not stopping in a hurry when necessary.

I've not driven a Tesla, but I'm going to guess they have different levels of braking between "not braking" and "wild application of brakes", so when I said it should "slow down" I obviously meant something in the middle.

Most people would describe the car suddenly coming to a halt apropos of nothing to be "wild application of brakes". Cmon.

One time years ago, I was driving on a four-lane highway when I observed a plastic bag flapping around the road ahead of me. Other cars were slowing or swerving to avoid it, which I thought was peculiar, so I also slowed a little bit but (admittedly) mostly to avoid hitting the other cars.

As I passed, I learned that the plastic bag was actually a dog that was (for unknown reasons) trying to cross the highway in moderately heavy traffic. It was pure luck on my part that I didn't hit the dog as it ran right behind my vehicle.

Sometimes even humans aren't the best judges in a split second of an object's estimated mass and/or whether it might contain some sort of soul. (I was around 30, and neither my cognition nor vision were noticeably impaired)

Similarly, I was on a highway and saw what looked like a crumpled up brown paper bag in the center of my lane and, rather than make the large maneuver of going around (I had passengers and didn't want to jostle them), I chose to straddle it. Welp, turns out it was a brown rock that had fallen onto the roadway. It managed to clear my oil pan (yay!), but didn't clear the floorboard and rotated longwise and propelled a bottle that was in a grocery bag on the floor into the face of one of my passengers.

Many driver-assist programs ignore distant stationary objects because the sensors aren't good enough to tell if they're really in the road or just close to the road, or maybe a metal plate that should be driven over, or whatever. But the collision detection for close-up objects is usually better than this.

What if its a pidgin? You want to smash into that at full speed?

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