Interchanges in your region - compare and contrast

[SSOWorld]

We (well most of us) know about the "supertall" stack interchanges of Texas (High-five, etc), California (Pangerson, Kellogg, four-level, etc), Florida, Georgia and Arizona. 

Did you know that there are quite a few U.S. states that have no system (motorway-to-motorway) interchange that exceeds 3 stacks?  In the USA, there's Illinois (Closest is the East St. Louis cluster****) but that is in the eye of the beholder), Indiana (every interchange on the Indy Beltway is a turntable - even those with 65 and 70 which enter downtown).  Minnesota also qualifies - the best you have is 3-levels downtown of both twin cities and the Can-of-Worms in Duluth. (Everything else is a cloverleaf, offset or turntable) Also Iowa - every interchange is a modified cloverleaf (outside the East Mixmaster in Des Moines and the 29-80 corridor in Council Bluffs.  Montana, Wyoming, North and South Dakota have nothing to write home about even in Fargo and Sioux Falls.  Nebraska has at most 3 stacks on all Omaha interchanges and I-180 ends at a cloverleaf.  Wisconsin? See Milwaukee.  Michigan has 4-levels in multiple municipalities.  I notice none in Utah.

I'll stop there. 

Note: I already saw "https://www.aaroads.com/forum/index.php?topic=23766.msg2361913#msg2361913" - I'm expanding!

Where are the highs and lows of the planet's freeways?  What unique pieces are out there.

[wanderer2575]

Actually, I think there are only three true four-level interchanges in Michigan:  I-75/I-696 in Hazel Park, I-96/M-39 in Detroit, and I-69/I-475 in Flint.  Every other four-leg freeway-to-freeway interchange doesn't physically exceed three levels, and the downtown Detroit ones formed from some bizarre impressionist influence, like this at I-75/I-94 or this at I-75/I-375 or this at I-94/I-96.  I'm sure part of the designs has to do with available land, but I wonder if part of them was a deliberate effort to not totally destroy neighborhood character by not having interchanges taller than three levels.

[thspfc]

There are too many three levels to count in WI . . . the only four levels however are the Marquette and Zoo.

[andrepoiy]

Generally, I'd say that half of Ontario's freeway-freeway interchanges are unique, due to the fact that Highway 401 has a collector-express system. However, the interchanges on the 401 in Toronto proper are not really designed to handle today's traffic volumes at all, despite how complex they might look. (The ramp speeds are too slow, and also not enough capacity). Freeway-to-non-freeway interchanges though, they're almost always Parclos in the GTA.

Highway 401 interchanges in GTA, from West to East:

407 ETR:


403/410: Fun fact: this was actually an incomplete interchange until 2018 (built in the 80s), as there was no access from 403 to WB 401, and vice versa.


427: The eastern end was supposed to connect to the now-cancelled Richview Expressway.


400: This interchange absolutely cannot handle the traffic volumes


Allen Road: This interchange on the other hand, isn't being used to full capacity because Allen Road is a stub freeway due to the rest of it being cancelled.


404/DVP: There's an HOV-only tunnel ramp from 404 to WB 401. The loop ramps have a small radius and you have to slow down to like 40 km/h.


Some other unique interchanges:

427/QEW/Gardiner Expressway:


407 ETR/403:


QEW/403/407 ETR:


QEW/420:


407 ETR/427:

[MCRoads]

Montana, Wyoming, North and South Dakota have nothing to write home about

I beg to differ:

https://goo.gl/maps/wQB4QRVgtJtqiz2p7

[SkyPesos]

Ohio only have 4 4-level stack interchanges I can think of, and 3 of them are in the Cleveland Area
- I-75/US 35
- I-71/I-90/I-490 (missing WB to NB movement)
- I-77/I-490
- I-77/I-480

As for what I think is the most unique interchange is in the state, it's I-71 and I-670, with the I-670 freeway carriageways splitting.

Also, especially in recent years, the state have added a bunch of braided ramps at major interchanges to reduce weaving.