unique SPUI-loop-ramp-thingy planned

[johndoe]

http://www.westfargopioneer.com/news/4128948-city-eyes-unique-interchange-sheyenne-st


I can't tell exactly what's going on here but looks like a variation on a continuous green and SPUI.  I'm trying to imagine how the lefts from and to the ramps to the left side of the photo align.  I can't seem to find the others the article mentions; anyone know of anything like this?

[lordsutch]

The two interchanges being referred to in the article are traditional SPUIs (Mall of America and Rochester).

I guess what they're proposing here is to only control the left turns and the carriageway headed toward the camera (southbound?) with a signal, while letting the other carriageway free-flow. I've never seen quite that configuration but I suppose it could work.

[froggie]

I guess what they're proposing here is to only control the left turns and the carriageway headed toward the camera (southbound?)

Correct.  The "camera" is pointing north.

[kalvado]

I guess what they're proposing here is to only control the left turns and the carriageway headed toward the camera (southbound?)

Correct.  The "camera" is pointing north.

If majority of traffic travels from south to east (bottom of pic to the right)  and back, with all other paths being secondary - probably they can achieve high enough throughput. And looks like north to south traffic is not a big concern..

[cl94]

This looks like one of the frankeninterchanges proposed on Kurumi's site, except the loops are on the same side of the arterial.

[kj3400]

Isn't this just a partially folded SPUI?

[Tarkus]

I'd call it a "folded spupclo", to use Kurumi's terminology.  I guess if you use the normal Parclo terminology, it'd be a "Spupclo AB".  It's a pretty clever design, and I'm quite curious to see more details of the little underpass bit where the two ramps intersect the surface street.

[cl94]

It's a pretty clever design, and I'm quite curious to see more details of the little underpass bit where the two ramps intersect the surface street.

The close side of the arterial is free-flowing. Still a three-phase signal, though. Why the heck they can't just build a SPUI or an A4/B4 is beyond me.

[lordsutch]

Googling about I found a corridor study that said that northbound there are frequent traffic backups at I-94, so giving a free-flow movement in that direction is preferred (hence why they're not planning something like a DDI). It looks like a loop ramp in the NE quadrant is precluded by the decision to stay in the existing ROW.

[froggie]

Why the heck they can't just build a SPUI or an A4/B4 is beyond me.

Because 85% of peak hour interchange traffic is to/from the East.

Sure, it'll require a 3-phase signal, but the vast majority of the green time at that signal is going to be for southbound Sheyenne, especially during the AM peak.  During the PM peak, I could see a little more evening out as they'll likely tie the NB left turn to WB 94 green into the WB loop ramp to SB movement.

[johndoe]

Bump!
https://www.youtube.com/embed/yqiJo25h-ak