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> "It’s impossible to stop at stop signs every time like they want you to." This sounds bad on the surface -- you are supposed to stop at stop signs. But I re

> "It’s impossible to stop at stop signs every time like they want you to." This sounds bad on the surface -- you are supposed to stop at stop signs. But I remembered that self-driving cars have to roll through stop signs too, because nobody remembers the right-of-way rules from driver's ed and so people will just take their turn early if it doesn't look like it will cause a crash. That means coming to a complete stop means you don't get your turn at all. Very unfortunate that the letter of the law and what people do in the real world aren't aligned. This isn't so much of a camera / AI problem -- a cop could give you a ticket here too.

radarsat1 5y ago
> a cop could give you a ticket here too. But won't. Or probably won't. Unless it's a speed trap. And if they do, they're not in the wrong to do so, but it doesn't mean you were 100% in the wrong to slow down to 10% instead of stopping. So it doesn't necessarily mean you need to change your behaviour, except to be wary of speed traps. And in case of danger, being able to stop is important, but there could be situations where slowing down is safer than jamming the breaks. And you might be able to explain that to the cop, or the cop might see what happened and give you a pass. Point is: situations can be complicated and nuanced, and AI is still very bad at this kind of social thinking. Personally I've come to the opinion that AI will never really be good at this kind of thing until it actually lives in and participates in society, whatever that may mean.
- Dylan16807 5y ago
  None of this thinking needs to be done in the moment. Someone looks at the rules, considers how they actually work out in practice, and decides on a policy. Then the AI can easily follow the policy. Not that you need anything anywhere close to AI to comprehend a stop sign braking policy.
toomanybeersies 5y ago
Genuine question, why are four-way stops a thing at all? Here in Australia, the usual setup for uncontrolled residential intersections (that don't have roundabouts) is to give one axis (?) right of way, and put stop signs on the cross axis. If neither direction is substantially wider or busier than the other, it's usually just arbitrary. This solves the problem of people being confused about right of way. When you come to a stop sign, you just give way to all traffic coming across the intersection.
- tbihl 5y ago
  I'm guessing your pictured intersections have lower speed limits and tighter geometry. As speeds increase, the amount of physical space needed to enter or cross traffic drastically increases. Even beyond that, as speeds increase, the estimation problem moves further away from human perception into something that would require the perception of a fast predatory bird, so even more space is needed just to be safe. When I think of conversions from 2 to 4 way stops, I think of an intersection in my town where the road was listed at 25mph but the enormously wide pavement easily supported driving 40-45mph comfortably, especially being at the bottom of a steep hill, and people drove accordingly. Completely separate from that is the issue of neighborhood groups trying to get inappropriate stop signs added to calm traffic. Stop signs are only for managing right of way; traffic calming should be handled by changes to street design. Disclaimer: Obviously any answer to this question will be a generalization that doesn't cover all circumstances
- mhb 5y ago
  > why are four-way stops a thing at all? Where I am, they are certainly overused - of course, because people agitate for them because safety. But you can read all about the traffic engineering justification for them in the Manual on Uniform Traffic Control Devices: https://mutcd.fhwa.dot.gov/htm/2009/part2/part2b.htm#section2B07 https://mutcd.fhwa.dot.gov/htm/2009/part2/part2b.htm#section...
- readflaggedcomm 5y ago
  Left turns out of a busy street work better if you have a turn to yourself, instead of waiting for traffic to break. There are some arrangements of stop lights that can make that better or much, much worse for one-lane traffic (I have one of each near me).
userbinator 5y ago
There's a similar story with speed limits --- the AI that sticks to the limit may become a danger to itself and others if the normal traffic goes faster, and likewise if some weather conditions slow down everyone else, it might be the idiot trying to stay at the limit and being a hazard to others.

radarsat1 5y ago

> a cop could give you a ticket here too. But won't. Or probably won't. Unless it's a speed trap. And if they do, they're not in the wrong to do so, but it doesn't mean you were 100% in the wrong to slow down to 10% instead of stopping. So it doesn't necessarily mean you need to change your behaviour, except to be wary of speed traps. And in case of danger, being able to stop is important, but there could be situations where slowing down is safer than jamming the breaks. And you might be able to explain that to the cop, or the cop might see what happened and give you a pass. Point is: situations can be complicated and nuanced, and AI is still very bad at this kind of social thinking. Personally I've come to the opinion that AI will never really be good at this kind of thing until it actually lives in and participates in society, whatever that may mean.

Dylan16807 5y ago
None of this thinking needs to be done in the moment. Someone looks at the rules, considers how they actually work out in practice, and decides on a policy. Then the AI can easily follow the policy. Not that you need anything anywhere close to AI to comprehend a stop sign braking policy.

toomanybeersies 5y ago

Genuine question, why are four-way stops a thing at all? Here in Australia, the usual setup for uncontrolled residential intersections (that don't have roundabouts) is to give one axis (?) right of way, and put stop signs on the cross axis. If neither direction is substantially wider or busier than the other, it's usually just arbitrary. This solves the problem of people being confused about right of way. When you come to a stop sign, you just give way to all traffic coming across the intersection.

tbihl 5y ago
I'm guessing your pictured intersections have lower speed limits and tighter geometry. As speeds increase, the amount of physical space needed to enter or cross traffic drastically increases. Even beyond that, as speeds increase, the estimation problem moves further away from human perception into something that would require the perception of a fast predatory bird, so even more space is needed just to be safe. When I think of conversions from 2 to 4 way stops, I think of an intersection in my town where the road was listed at 25mph but the enormously wide pavement easily supported driving 40-45mph comfortably, especially being at the bottom of a steep hill, and people drove accordingly. Completely separate from that is the issue of neighborhood groups trying to get inappropriate stop signs added to calm traffic. Stop signs are only for managing right of way; traffic calming should be handled by changes to street design. Disclaimer: Obviously any answer to this question will be a generalization that doesn't cover all circumstances
mhb 5y ago
> why are four-way stops a thing at all? Where I am, they are certainly overused - of course, because people agitate for them because safety. But you can read all about the traffic engineering justification for them in the Manual on Uniform Traffic Control Devices: https://mutcd.fhwa.dot.gov/htm/2009/part2/part2b.htm#section2B07 https://mutcd.fhwa.dot.gov/htm/2009/part2/part2b.htm#section...
readflaggedcomm 5y ago
Left turns out of a busy street work better if you have a turn to yourself, instead of waiting for traffic to break. There are some arrangements of stop lights that can make that better or much, much worse for one-lane traffic (I have one of each near me).

userbinator 5y ago

There's a similar story with speed limits --- the AI that sticks to the limit may become a danger to itself and others if the normal traffic goes faster, and likewise if some weather conditions slow down everyone else, it might be the idiot trying to stay at the limit and being a hazard to others.