4 ms·

We seem to use fairly modern systems out here. They do appear to be programmed in a ripple type green wave progression depending on congestion. You'll hit one o

We seem to use fairly modern systems out here. They do appear to be programmed in a ripple type green wave progression depending on congestion. You'll hit one or two reds for every five or six intersections. The intersection I have in mind has a left turn on it. The left turn is not timed and will only cue under two conditions: at the opening phase to main traffic, and if there is no oncoming traffic for the initial ten (or so) seconds. Otherwise it waits until the entire phase is complete (with a 120 second timeout) before it resets. At night time it will cue almost immediately. One question that I have though, and you'll have to pardon my ignorance. Would it be efficient for intersections to always be red until a vehicle approaches? Then only allow X number of vehicles before turning red again. Basically turning the traffic signal into an "advanced" stop sign, with the expectation that you stop by default. Unless the system detects there is no cross traffic. Then you can have much more rapid phases and it protects against folks racing to the next green (red when they arrive) light.

__MatrixMan__ 2y ago
As a software engineer who worked in support of civil engineers 7 years ago, I'm not exactly an expert myself, just picked up bits of domain knowledge on the job. And yeah, what you're describing re: left turns makes sense. I know there's a hybrid mode where you only serve the turns if there is demand, but otherwise you're running coordinated--but I am not sure about the nuances re: how the interplay of those modes actually works. I expect that there are certain conditions which would indeed benefit from what you're describing. Especially if the signals could inform one another that a platoon is heading that way. On a straight shot under light conditions you might end up having to stop only once, after which you're now on a path that was coordinated precisely for you.
- DCH3416 2y ago
  I've always wanted to run a traffic simulation to see how well that type of configuration would work. Because if you look at your car's trip computer the average speed from stop and go traffic tends to hover around half the prevailing speed. Traffic signals in holland seem to operate similar to how I described. I'm just not sure how that would translate to somewhere like the US where you have much higher traffic volumes and faster (crazier) drivers.

__MatrixMan__ 2y ago

As a software engineer who worked in support of civil engineers 7 years ago, I'm not exactly an expert myself, just picked up bits of domain knowledge on the job. And yeah, what you're describing re: left turns makes sense. I know there's a hybrid mode where you only serve the turns if there is demand, but otherwise you're running coordinated--but I am not sure about the nuances re: how the interplay of those modes actually works. I expect that there are certain conditions which would indeed benefit from what you're describing. Especially if the signals could inform one another that a platoon is heading that way. On a straight shot under light conditions you might end up having to stop only once, after which you're now on a path that was coordinated precisely for you.

DCH3416 2y ago
I've always wanted to run a traffic simulation to see how well that type of configuration would work. Because if you look at your car's trip computer the average speed from stop and go traffic tends to hover around half the prevailing speed. Traffic signals in holland seem to operate similar to how I described. I'm just not sure how that would translate to somewhere like the US where you have much higher traffic volumes and faster (crazier) drivers.