The "Lipstick interchange"

[tradephoric]

^Just like a Town Center Intersection (TCI) you can have commercial development in the median where the arterial street branches out.  Here's an example of a gas station at a TCI in California:

[tradephoric]

Since the crossroad gets signalized anyway I wonder if there is a big benefit to that extra bridged-ramp.  I also wonder how difficult pedestrian crossings would be in those two unsignalized corners: they either cross a free right or free left turn.  In my head it's moving close to a split diamond, but with a wide median rather than two cross roads.  (or like a "town center" + freeway)  That would result in four two-phase signals.

The interchange does closely resemble a split diamond or volleyball interchange.  Here is an interchange in Edmonton that closely resembles the interchange i was picturing:

https://www.google.com/maps/@53.4805077,-113.4935405,468m/data=!3m1!1e3

...and just a mile to the west is this Volleyball (or split diamond) interchange.  By the way is there a technical difference between a split diamond interchange and a volleyball interchange or are they essentially the same thing?

https://www.google.com/maps/@53.4828018,-113.5169789,234m/data=!3m1!1e3

[kphoger]

By the way is there a technical difference between a split diamond interchange and a volleyball interchange or are they essentially the same thing?

They are the same thing.

kurumi came up with the term.  See below, from his website:

This interchange is better known as the 3-level diamond or split-level diamond. The term "volleyball interchange," one of my few contributions to colloquial English, will get you blank stares at a job interview, but a smile of recognition among many road fans.

[jakeroot]

Split diamond interchanges are pretty unusual in WA, although one does exist in Spokane: https://goo.gl/JA2htC

Weirdly, the double left turns at this interchange permit turns on red, but the single lefts do not. The difference is that, the NTOR restriction is for traffic turning left across off-ramp traffic, rather than
across NB or SB arterial traffic.

Operationally, I don't see that many differences between split diamonds and signalized roundabout interchanges. The video posted on the last page from Indiana shows what is effectively a split diamond roundabout:

https://www.youtube.com/watch?v=r_fL4rqvZG0

[froggie]

Split-level diamond = volleyball.

Split diamond ≠ split level diamond.

Split diamond = elongated diamond and is the general term for diamond interchanges where the ramps are "split" between two or more cross-roadways.  Jake:  the Thor St/Freya St interchange on I-90 (Exit 283B) is a better Spokane example.  Other examples include I-494 MN Exit 65 (5th Ave & 7th Ave), I-55 MS Exit 107 (Colony Park Blvd & Madison Ave), and I-664 VA Exit 4 (Roanoke Ave & Chestnut Ave).

[jakeroot]

Jake:  the Thor St/Freya St interchange on I-90 (Exit 283B) is a better Spokane example.

I was going to post it, but it does not involve any freeway ramps, only frontage roads (although it once did -- westbound exit). The Exit 287 interchange at least involves two freeway ramps.

[tradephoric]

Split diamond interchanges are pretty unusual in WA, although one does exist in Spokane: https://goo.gl/JA2htC

That's a great example of a freeway connecting to a one-way couplet.  It seems like these types of interchanges would naturally exist along one-way grids but i'm surprised how few examples i could find.

[kphoger]

Split diamond interchanges are pretty unusual in WA, although one does exist in Spokane: https://goo.gl/JA2htC

That's a great example of a freeway connecting to a one-way couplet.  It seems like these types of interchanges would naturally exist along one-way grids but i'm surprised how few examples i could find.

Split (not split level) diamond interchange at a one-way couplet near me in Wichita:  I-135 & 1st & 2nd Streets

[froggie]

Jake:  the Thor St/Freya St interchange on I-90 (Exit 283B) is a better Spokane example.

I was going to post it, but it does not involve any freeway ramps, only frontage roads (although it once did -- westbound exit). The Exit 287 interchange at least involves two freeway ramps.

Whether the ramps directly tie into frontage roads or not doesn't matter.  Exit 283B is still fundamentally a split-diamond.

[jakeroot]

Jake:  the Thor St/Freya St interchange on I-90 (Exit 283B) is a better Spokane example.

I was going to post it, but it does not involve any freeway ramps, only frontage roads (although it once did -- westbound exit). The Exit 287 interchange at least involves two freeway ramps.

Whether the ramps directly tie into frontage roads or not doesn't matter.  Exit 283B is still fundamentally a split-diamond.

I don't disagree. I was just trying to find an example where the frontage roads were not part of a local grid system, rather just natural extensions of an off-ramp.  Exit 283B could not have been easily built as anything but a split diamond, however Exit 287 very easily could have been built as a regular diamond, or something else.

[tradephoric]

I created a model of the interchange in SYNCHO. 
https://www.youtube.com/watch?v=2IZ3lzQ3ISA&feature=youtu.be

Below is a slight modification to the model that includes loop ramps.  The advantage is it takes up less ROW and there are fewer pedestrian crossing along the arterial.  The disadvantage is it increases driver delay quite significantly for traffic exiting the freeway wanting to continue right on the arterial (much farther distance traveled).  Still, the operational advantages of either of these models would blow the DDI out of the water. 

https://www.youtube.com/watch?v=HFlo90vZxmM

[NE2]

Lipstick on a pig parclo B4?

[tradephoric]

Lipstick on a pig parclo B4?

Since i called it the "lipstick" interchange i feel like i was setting myself up for that!  One of the knocks against any Parclo is the amount of ROW they take up.  But with a Milwaukee interchange it can once again be quite compact....



Not to mention the Milwaukee B minimizes travel times through the interchange when compared to the DDI, Diamond, Milwaukee A, Parclo B, or Synchronized interchange (i'm sure you could add SPUI into the list but this particular study didn't analyze the SPUI).  Notice how poorly the DDI is for through traffic on the arterial?  It's even worse than the lowly diamond interchange...


https://digitalcommons.wayne.edu/cgi/viewcontent.cgi?article=2844&context=oa_dissertations

[NE2]

[kphoger]

Notice how poorly the DDI is for through traffic on the arterial?  It's even worse than the lowly diamond interchange...

Has anyone ever claimed otherwise?  I thought everyone knew all along that through-traffic on the arterial was going to be sacrificing efficiency for the sake of the other movements.

[tradephoric]

Has anyone ever claimed otherwise?  I thought everyone knew all along that through-traffic on the arterial was going to be sacrificing efficiency for the sake of the other movements.

The problem is the DDI has longer travel times for other movement compared to the Milwaukee B.  I could understand nearly 50 second longer travel times for arterial traffic along the DDI if it meant a dramatic drop in travel times for the other movements... but that's not what you see. 



According to the study the DDI has worse travel times for every movement compared to the Milwaukee B except for the "Right turn from freeway to arterial" movement (where they are basically the same).  I question if delay is lower at a DDI for that movement since at many DDI's you are restricted from making a simple right on red coming off the freeway.  Here is a streetview of the newly constructed University Parkway DDI in Florida.  To me "NO TURN ON RED" equals DELAY. 


https://www.google.com/maps/@27.3883793,-82.4468742,3a,75y,55.35h,87.02t/data=!3m6!1e1!3m4!1sQHH9K4LBB1Y0PATz1sf3Qw!2e0!7i13312!8i6656

[kphoger]

Has anyone ever claimed otherwise?  I thought everyone knew all along that through-traffic on the arterial was going to be sacrificing efficiency for the sake of the other movements.

The problem is the DDI has longer travel times for other movement compared to the Milwaukee B.  I could understand nearly 50 second longer travel times for arterial traffic along the DDI if it meant a dramatic drop in travel times for the other movements... but that's not what you see. 

According to the study the DDI has worse travel times for every movement compared to the Milwaukee B except for the "Right turn from freeway to arterial" movement (where they are basically the same).

Sorry, I meant that people aren't generally comparing a DDI to a Milwaukee B interchange, because they've never heard of a Milwaukee B interchange.  Also, DDIs tend to get built because the state only wants to install one bridge, and that advantage goes out the window with a Milwaukee B interchange.  It seems to me that DDIs are installed as a cheap-ish upgrade from a standard diamond interchange.  And, if you look at that chart, a DDI does better than a diamond on every movement except through-traffic on the arterial–and even that's just barely worse.

[tradephoric]

It's one thing to build a DDI to replace an existing Diamond where you don't have the space to build anything else.  It's entirely different to build a supersized DDI where a more efficient interchanges could fit.  Does this look like a cheap-ish upgrade from a standard diamond interchange to you?


The Split Milwaukee B interchange wouldn't fit everywhere, but when Florida decides to build these massive DDI's it suddenly becomes an option.  Below is the required footprint of the Split Milwaukee B interchange juxtaposed over the University Parkway DDI in Florida.  If anything the Split Milwaukee B would take up less ROW than that massive DDI they built... and there would be a lot less delay for nearly every turning movement.

[kphoger]

It's one thing to build a DDI to replace an existing Diamond where you don't have the space to build anything else.  It's entirely different to build a supersized DDI where a more efficient interchanges could fit.  Does this look like a cheap-ish upgrade from a standard diamond interchange to you?


The Split Milwaukee B interchange wouldn't fit everywhere, but when Florida decides to build these massive DDI's it suddenly becomes an option.  Below is the required footprint of the Split Milwaukee B interchange juxtaposed over the University Parkway DDI in Florida.  If anything the Split Milwaukee B would take up less ROW than that massive DDI they built... and there would be a lot less delay for nearly every turning movement.

All I see in that first picture is pavement, barriers, sign gantries and stoplights.  Not knowing how much r/o/w they had to work with, I couldn't say how cheap-ish that looks to me.  What I do not see in that picture are any additional bridges, and I'd say that has a lot of bearing on the price tag.

With the arterial passing underneath the freeway, it's going to be two bridges no matter what–one for each carriageway of the freeway.  Changing that to a "lipstick interchange" would increase that number by at least two more bridges, probably four.  That is a significant increase in construction cost.  No matter how you slice it, a DDI has a lot less bridge work than the "lipstick".

[jakeroot]

What I do not see in that picture are any additional bridges, and I'd say that has a lot of bearing on the price tag.

Judging by the length of the overpasses corresponding exactly to the width of the roadway, the overpasses were rebuilt to accommodate the new width of the arterial. Parclo designs would have likely required wider overpasses but a narrower arterial and shorter overpasses.

[kphoger]

I don't know how closely related this is, but check out the junction of TX-136 & TX-207.

[Road Hog]

I like the roundabout option for the intersection of US 75 and US 82 in Sherman, TX. All traffic exiting from one to the other must negotiate the frontage roads paralleling each. Right turns are easy, left turns mean hitting 3 traffic lights. A roundabout setup would eliminate the need for signals.

(My preference for this particular interchange is a stack with flyovers, but this is a road board, not a comedy board.)

[kphoger]

I like the roundabout option for the intersection of US 75 and US 82 in Sherman, TX. All traffic exiting from one to the other must negotiate the frontage roads paralleling each. Right turns are easy, left turns mean hitting 3 traffic lights. A roundabout setup would eliminate the need for signals.

(My preference for this particular interchange is a stack with flyovers, but this is a road board, not a comedy board.)

Volleyball.

[tradephoric]

I don't know how closely related this is, but check out the junction of TX-136 & TX-207.

There are a few other examples of this interchange that i know of but not nearly as compact as your example:
https://www.google.com/maps/@42.3711408,-71.269529,463m/data=!3m1!1e3
https://www.google.com/maps/@42.5937032,-70.9634984,919m/data=!3m1!1e3

Here's my interpretation of the interchange on SYNCHRO:
https://www.youtube.com/watch?v=yplEKcvOk5o

[Amtrakprod]

A mirror image with weaving instead of lights, MA 128 at US 20: https://www.google.com/maps/@42.3708793,-71.2696918,626m/data=!3m1!1e3
Somewhat close, I-270 at MO 100: https://www.google.com/maps/@38.6026606,-90.4503011,662m/data=!3m1!1e3

I was going to post the first one lol


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