Mistake or Possible? Artery ending with shorter cycle time?

[TedM]

I'm using a partial previous model from my predecessor to make a intersection in the artery full time.

Every Intersection is running a 240sec cycle. However the last intersection is actually running 220 second cycle.

Is this possible to model.. My thinking is to never mix things up like that and just change every thing to 240.

Another issue I'm having is I have an intersection where almost adds up to the split except 10 seconds.

Which on my system is a skippible/alternative phase with those 10sec.

[bullock]

You have three options that I can think of, each with its advantages & disadvantages. I'm not sure which you might prefer.

You can enter splits that sum to 220 sec for that one intersection. You'll have to put up with the warnings everytime you leave that intersection's parameters, warnings about the splits not summing to the cycle length. I think the 220 sec intersection will show correctly on the diagram, but the bands will be unreliable as they won't be truly periodic, and coordination would be short lived.

If you don't want to keep seeing the warnings about the splits not summing to the cycle length, you should artifically make them sum to 240 sec, in which case the intersection will no longer be displayed accurately (with total timings off by about 9%), and the bands will still be unreliable, but at least you won't keep seeing the warnings.

A third alternative would be to just remove that intersection for the diagram, in which case, there are yet different inaccuracies introduced into the diagram (which is now missing a signal) and the notion of progression shown on the diagram through the link lacking the signal is still probably a bit of an illusion.

Regarding the second issue, what to do may depend on what happens to those 10 seconds when that optional phase is skipped. Are the 10 seconds alloted to another phase, so the cycle length is unchanged, or are the 10 seconds removed altogether from the cycle so sometimes you run with a shorter cycle at that intersection? If it's the former, then in the software you'll probably just want to add the 10 seconds to whichever phase most frequently gets them, the optional phase or the essential one. In the latter case (where some cycles run 10 seconds shorter than others), if both the skipping and the non skipping occur fairly frequently, then it's going to be pretty much futile to maintain any coordination (unless you're really lucky to be using 20 or 30 second cycles, in which case adding 10 seconds still makes it somewhat commensurate). I'd probably just pick the case that occurs most frequently, but recognize that either way you do it, coordination won't be maintained for long anyway. This then becomes similar to the first issue you raised.

Hope this helps.

Maybe someone else will have some suggestions.

Regards.
Greg