Hacker News Reader

Comment by js8 | Hacker News Reader

"I find myself unable to decide for a fraction of a second whether to stop for a traffic light that just turned yellow or to go through"

I had a similar problem, and I resolved it by training myself to remind myself of a point of no return, that is, a distance from the light at which I will go no matter what. So every time I see a traffic light, I decide where is the point of no return.

I think establishing point of no return is the standard method of dealing with this. For example, parachute jumpers have a certain altitude at which they have to make the decision whether to land on the main parachute or backup parachute if something goes wrong with the main one.

View on HN

The paper points out that this doesn't resolve the problem in the discussion about the crossing gate; all this approach does is move the decision from "do I jump" to "have I met the point of no return yet", which is still a discrete decision over a continuous input.

However, the further it goes, the more clear the second one gets. I.e. "am I already at the point of no return, I guess not, it's unclear. Oh wait, now I am, let's trigger."

So, Buridan’s Principle is correct for time-invariant systems. But as far as I can see you can totally build a time-dependent system which simply picks option 1 after being undecisive for time T.

I think the principle would state that by always picking option 1 you are no longer making a decision based on the input.

This is discussed in the paper under section 3: "Other Asses", in the paragraph starting "One way to circumvent Buridan’s Principle is to eliminate the decision".

The fact that we are discussing a yellow light and not a red one is because the yellow light is a mitigation that significantly reduces the risk of harm from making a wrong (or, shall we say, suboptimal?) decision.

Agreed - the majority of drivers will now be making the discrete decision "Is green or amber" not "Is amber or red".

That is to say, that the proportion of drivers having to make the risky decision (i.e. if they were to decide to accelerate through the amber) is significantly reduced... although interestingly I think the principle states that as T(amber) << T(green) the liklihood of indecision for that second case now does increase.

I don't think there is any doubt about what the color is (or, given color-blind drivers, which light is on); the only issue a law-abiding driver is supposed to consider, on seeing the yellow light come on, is whether one can stop within the remaining distance. Of course, in practice, it's more complicated...

The practice of putting cameras on lights and then reducing the duration of the yellow light is not only an abuse of power but also dangerous.

Reply on news.ycombinator.com