The "Lipstick interchange"

[tradephoric]

Is there an example of an interchange like this?  I overlaid it on top of the University Parkway DDI in Florida for perspective.  Below is a link to a similar interchange design i used for inspiration:

I-94 & Conner (Detroit, MI):
https://www.google.com/maps/@42.3957705,-82.9875861,388m/data=!3m1!1e3

[kphoger]

Plenty of weaving and left-side merging to go around there, I see...

[tradephoric]

Plenty of weaving and left-side merging to go around there, I see...

The four green dots in the picture represent traffic signals.  The traffic signals should help with the merge points.

[tradephoric]

Here is a simplified version of the interchange i was imagining:

[kphoger]

Huh.  The interchange I thought of turns out to not quite match your drawing, but I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

[NE2]

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

[tradephoric]

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

I was literally about to post a link to this interchange!  It's not quite the same design though as the freeway off-ramps are outside of the "square".     

[kphoger]

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

I'm not entirely sure that's equivalent.  I'm trying to trace where all the turning movements go in relation to one another, and it's making my brain hurt.  At any rate, here's the one I had thought of, but I don't think it's quite equivalent either.

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

I was literally about to post a link to this interchange!  It's not quite the same design though as the freeway off-ramps are outside of the "square".     

You replied while I was typing.  Yes, "outside of the square" describes what I was thinking didn't match up.

[kphoger]

↓  Here's my rendering of your interchange  ↓

[tradephoric]

Thank you kphoger!  I'm not good with rendering these designs and botch them up pretty bad.  Your drawing is much better at showing this conceptual design.   If you get a chance could you render up the simplified interchange design too?

[hotdogPi]

I feel like the grade might be too steep here.

[tradephoric]

I feel like the grade might be too steep here.

Here's a streetview showing the interchange grade at I-94 and Conner in Detroit.  After exiting the freeway, drivers only travel 620 feet before merging onto Conner Street.  It gives you an idea of what the off-ramp grade might look like.

https://www.google.com/maps/@42.3957152,-82.9887019,3a,75y,29.5h,86.52t/data=!3m6!1e1!3m4!1s1tvG0JdEGYNLdo5zuJB2nw!2e0!7i16384!8i8192!5m1!1e1

[kphoger]

Thank you kphoger!  I'm not good with rendering these designs and botch them up pretty bad.  Your drawing is much better at showing this conceptual design.   If you get a chance could you render up the simplified interchange design too?

I feel like the grade might be too steep here.

Depends how much land the interchange takes up.  Look at the Mexican almost-example I linked to earlier.

[tradephoric]

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

[johndoe]

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.

I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

Was it this one?  https://www.google.com/maps/@19.6238016,-99.1925003,200m/data=!3m1!1e3
Slightly different looking than the ones built in the US!

[US 89]

I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

Was it this one?  https://www.google.com/maps/@19.6238016,-99.1925003,200m/data=!3m1!1e3
Slightly different looking than the ones built in the US!

From what I can see, there is absolutely zero signage indicating that the directions cross over. And the eastern crossover isn't even signalized!
I wonder what the crash rate there is, or how many drivers go the wrong way on the overpass.

[Brandon]

I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

Was it this one?  https://www.google.com/maps/@19.6238016,-99.1925003,200m/data=!3m1!1e3
Slightly different looking than the ones built in the US!

From what I can see, there is absolutely zero signage indicating that the directions cross over. And the eastern crossover isn't even signalized!
I wonder what the crash rate there is, or how many drivers go the wrong way on the overpass.

Holy fuckarooni, Batman!  The only signage I see is this:
https://goo.gl/maps/LobQdTKNVys
https://goo.gl/maps/8cBVo7o7tzt

[US 89]

I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

Was it this one?  https://www.google.com/maps/@19.6238016,-99.1925003,200m/data=!3m1!1e3
Slightly different looking than the ones built in the US!

From what I can see, there is absolutely zero signage indicating that the directions cross over. And the eastern crossover isn't even signalized!
I wonder what the crash rate there is, or how many drivers go the wrong way on the overpass.

Holy fuckarooni, Batman!  The only signage I see is this:
https://goo.gl/maps/LobQdTKNVys
https://goo.gl/maps/8cBVo7o7tzt

How did I miss those? 
I love that second one. Can I go to the right of the gore point sign or not? 

[kphoger]

I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

Was it this one?  https://www.google.com/maps/@19.6238016,-99.1925003,200m/data=!3m1!1e3
Slightly different looking than the ones built in the US!

From what I can see, there is absolutely zero signage indicating that the directions cross over. And the eastern crossover isn't even signalized!
I wonder what the crash rate there is, or how many drivers go the wrong way on the overpass.

Holy fuckarooni, Batman!  The only signage I see is this:
https://goo.gl/maps/LobQdTKNVys
https://goo.gl/maps/8cBVo7o7tzt

How did I miss those? 
I love that second one. Can I go to the right of the gore point sign or not? 

I stumbled upon a DDI in Mexico while I was looking.  I didn't realize any DDIs existed there.

Was it this one?  https://www.google.com/maps/@19.6238016,-99.1925003,200m/data=!3m1!1e3
Slightly different looking than the ones built in the US!

From what I can see, there is absolutely zero signage indicating that the directions cross over. And the eastern crossover isn't even signalized!
I wonder what the crash rate there is, or how many drivers go the wrong way on the overpass.

Holy fuckarooni, Batman!  The only signage I see is this:
https://goo.gl/maps/LobQdTKNVys
https://goo.gl/maps/8cBVo7o7tzt

Technically there is this (vague) (advance) signage indicating a veer to the left, but only on one approach.

[kphoger]

Just found another DDI in Mexico.  How did I not realize these existed down there?

https://goo.gl/maps/aSbssirX4fB2

[Brandon]

Just found another DDI in Mexico.  How did I not realize these existed down there?

https://goo.gl/maps/aSbssirX4fB2

Holy head-on collisions!  How can you tell it's a DDI from the 2017 Google Street View!?!  2012 has some signage, but 2017 completely lacks signage.

[kphoger]

Holy fuckarooni, Batman! 

Holy head-on collisions! 

Having a good Friday, are you?   

[cjw2001]

Who needs complexity and stop lights when a roundabout will work just fine in a similar layout ... https://www.google.com/maps/@39.9419367,-86.0187932,19.19z

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

https://www.youtube.com/watch?v=yG1ittH-seI

[jakeroot]

Something tells me that will perform better than the typical multi-lane roundabout. Very Australian/Kiwi design (not British, as it's not large enough nor would the entrance ramps have chicanes).

[tradephoric]

Florida is planning several more DDI's including one at I-75 & Martin Luther King Jr. Blvd near Tampa.  However, the "lipstick interchange" as i'm affectionately calling it could fit in the same amount of ROW as the proposed DDI.