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National Boards => General Highway Talk => Topic started by: johndoe on October 28, 2015, 07:38:22 PM

Title: Utah: modified CFI (at grade separation)
Post by: johndoe on October 28, 2015, 07:38:22 PM
(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.roadsbridges.com%2Fsites%2Frb%2Ffiles%2Fimce-images%2FPhoto2.jpg&hash=d1b3305b08cca676ab2cb7e5ed94b4e4d4ff0c13)
More info and animation here:
http://www.udot.utah.gov/i15southdavis/?page_id=1214
Title: Re: Utah: modified CFI (at grade separation)
Post by: NE2 on October 28, 2015, 11:16:40 PM
More SPUish than anything.
Title: Re: Utah: modified CFI (at grade separation)
Post by: cl94 on October 28, 2015, 11:58:44 PM
Really a 1/4 DDI
Title: Re: Utah: modified CFI (at grade separation)
Post by: triplemultiplex on October 29, 2015, 11:28:38 AM
It's more reminiscent of the types of intersections Utah has on the Bangerter Highway in suburban SLC where left turning traffic crosses the opposite lane of traffic ahead of the intersection and then meets the cross street.

examples:
http://mapper.acme.com/?ll=40.50817,-111.98249&z=18&t=S (http://mapper.acme.com/?ll=40.50817,-111.98249&z=18&t=S)
http://mapper.acme.com/?ll=40.62397,-111.97640&z=17&t=S (http://mapper.acme.com/?ll=40.62397,-111.97640&z=17&t=S)
Title: Re: Utah: modified CFI (at grade separation)
Post by: Henry on October 29, 2015, 01:27:04 PM
Quote from: NE2 on October 28, 2015, 11:16:40 PM
More SPUish than anything.
I have to disagree on that assessment, since the ramps themselves do not come to the same location. In fact, there's one ramp that leads to a different street altogether.

Quote from: cl94 on October 28, 2015, 11:58:44 PM
Really a 1/4 DDI
Only the left turn lanes on the crossover to southbound I-15 move to the opposite side of the road. Other than that, it looks like a normal interchange.
Title: Re: Utah: modified CFI (at grade separation)
Post by: vdeane on October 29, 2015, 02:58:01 PM
Quote from: Henry on October 29, 2015, 01:27:04 PM
Quote from: cl94 on October 28, 2015, 11:58:44 PM
Really a 1/4 DDI
Only the left turn lanes on the crossover to southbound I-15 move to the opposite side of the road. Other than that, it looks like a normal interchange.
That's why he called it a 1/4 DDI.  One of the four movements that would cross over in a DDI crosses over here.
Title: Re: Utah: modified CFI (at grade separation)
Post by: cl94 on October 29, 2015, 05:20:05 PM
Quote from: triplemultiplex on October 29, 2015, 11:28:38 AM
It's more reminiscent of the types of intersections Utah has on the Bangerter Highway in suburban SLC where left turning traffic crosses the opposite lane of traffic ahead of the intersection and then meets the cross street.

examples:
http://mapper.acme.com/?ll=40.50817,-111.98249&z=18&t=S (http://mapper.acme.com/?ll=40.50817,-111.98249&z=18&t=S)
http://mapper.acme.com/?ll=40.62397,-111.97640&z=17&t=S (http://mapper.acme.com/?ll=40.62397,-111.97640&z=17&t=S)

Both of those examples are CFIs
Title: Re: Utah: modified CFI (at grade separation)
Post by: johndoe on October 29, 2015, 09:17:48 PM
...what's in a name...who cares?

It's interesting that the DCD has gotten so popular, partially because of 2-phase signals, like CFI, yet the east ramp here has 4 phases.  Instead of making the traditional 3-phase simplified, this is more complicated.
Title: Re: Utah: modified CFI (at grade separation)
Post by: roadfro on October 30, 2015, 01:10:45 AM
Quote from: johndoe on October 29, 2015, 09:17:48 PM
It's interesting that the DCD has gotten so popular, partially because of 2-phase signals, like CFI, yet the east ramp here has 4 phases.  Instead of making the traditional 3-phase simplified, this is more complicated.

Unless I'm missing something, the eastern ramp intersection (I-15 north) can run three phases:
1) EB & WB thru
2) EB left & WB left crossover (NB off ramp right turn can overlap)
3) NB off ramp
Title: Re: Utah: modified CFI (at grade separation)
Post by: johndoe on October 30, 2015, 08:33:57 AM
Quote from: roadfro on October 30, 2015, 01:10:45 AM
Quote from: johndoe on October 29, 2015, 09:17:48 PM
It's interesting that the DCD has gotten so popular, partially because of 2-phase signals, like CFI, yet the east ramp here has 4 phases.  Instead of making the traditional 3-phase simplified, this is more complicated.

Unless I'm missing something, the eastern ramp intersection (I-15 north) can run three phases:
1) EB & WB thru
2) EB left & WB left crossover (NB off ramp right turn can overlap)
3) NB off ramp
Good point...I'm not sure what I was thinking.  Maybe this is why the person mentioned the similarity to a spui, since the same movements exist (except there is only one ramp and one left is likely permissive) It'd be cool to see their ring and barrier setup.
Title: Re: Utah: modified CFI (at grade separation)
Post by: johndoe on November 03, 2015, 06:25:13 PM
I'll post this here instead of starting a new thread since it's related: http://www.heraldtribune.com/article/20151026/ARTICLE/151029729

It's a variation being considered in Florida.
Title: Re: Utah: modified CFI (at grade separation)
Post by: jakeroot on November 03, 2015, 07:18:53 PM
Quote from: johndoe on November 03, 2015, 06:25:13 PM
I'll post this here instead of starting a new thread since it's related: http://www.heraldtribune.com/article/20151026/ARTICLE/151029729

It's a variation being considered in Florida.

I really need a higher res screenshot than this. I can't figure out what the hell is going on, short of some obvious Utah-inspired lefts turns:

(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fwww.heraldtribune.com%2Fapps%2Fpbcsi.dll%2Fbilde%3FSite%3DSH%26amp%3BDate%3D20151026%26amp%3BCategory%3DARTICLE%26amp%3BArtNo%3D151029729%26amp%3BRef%3DAR%26amp%3BimageVersion%3DMain%26amp%3BMaxW%3D728%26amp%3Blogo%3D%2Fimages%2Fwatermark.gif%26amp%3Blogoxpos%3D0%26amp%3Blogoypos%3D0&hash=fa107b94377e03340f51c543c3fb29417a11ab3d)
Title: Re: Utah: modified CFI (at grade separation)
Post by: johndoe on November 04, 2015, 07:26:04 AM
Here we go: http://www.ishgd2015.net/s/113-Hybrid-Interchange-Designs-Evolving-Something-new-from-Something-Old.pdf