What do you think of these?
https://www.google.com/maps/@25.0562365,55.2481096,1787m/data=!3m1!1e3
At first, they seemed very flashy, extremely overbuilt, but then I noticed a couple of interesting things (at least with that particular interchange), such as being able to change directions on your present route. Probably not useful most of the time, but there have been a few times I've found myself on the wrong lane of an interchange, unable to exit safely, so I have to waste time getting to the next exit to turn myself around.
Here's another one:
(https://upload.wikimedia.org/wikipedia/commons/thumb/1/1d/Circle_Interchange_Chicago.jpg/640px-Circle_Interchange_Chicago.jpg)
There is one in North Carolina, too: http://www.enr.com/articles/12107-rare-turbine-design-for-charlotte-s-i-85-485-interchange
Half-turbine-half-cloverleafs in Louisiana:
I-12 at US 190 (https://www.google.com/maps/place/Covington,+LA/@30.4298269,-90.0857547,1548m/data=!3m1!1e3!4m5!3m4!1s0x86275c309b2b89e7:0x70eb03821763520!8m2!3d30.4754702!4d-90.1009108)
I-10 at I-510/LA 47 (https://www.google.com/maps/place/New+Orleans,+LA/@30.0593949,-89.9424797,1556m/data=!3m1!1e3!4m5!3m4!1s0x8620a454b2118265:0xdb065be85e22d3b4!8m2!3d29.9510658!4d-90.0715323)
I'd actually like to know why these intersections were built with this design as opposed to pure turbines or pure cloverleafs. Perhaps environmental conditions?
Looks like the Albany circle interchange: https://www.google.com/maps/@42.6437119,-73.7511452,656m/data=!3m1!1e3
We also have another hybrid: https://www.google.com/maps/@42.6946971,-73.8390212,1033m/data=!3m1!1e3
I'm not seeing the part that would allow someone to turn around, through.
The one between I-4 and I-275 uses slower speed ramps with a single lane in all directions. The exchange would have been better if it was built as a multi level stack interchange instead. Having drove through the exit many times, I'm not impressed with turbine interchanges.
Does the "Circle" in Chicago count?
https://en.wikipedia.org/wiki/Jane_Byrne_Interchange
We have some over here such as this https://www.google.co.uk/maps/@51.4007364,-0.5377096,1751m/data=!3m1!1e3
Quote from: DevalDragon on August 01, 2016, 06:10:54 PM
Does the "Circle" in Chicago count?
https://en.wikipedia.org/wiki/Jane_Byrne_Interchange
I think so. It's the second example in the OP. :sombrero:
Quote from: CtrlAltDel on August 01, 2016, 09:35:59 PM
Quote from: DevalDragon on August 01, 2016, 06:10:54 PM
Does the "Circle" in Chicago count?
https://en.wikipedia.org/wiki/Jane_Byrne_Interchange
I think so. It's the second example in the OP. :sombrero:
That's the interchange I most closely associate my hometown with! As a kid, I thought it was cool and unique, as opposed to the rather boring-looking stack interchanges.
Quote from: Truvelo on August 01, 2016, 06:36:10 PM
We have some over here such as this https://www.google.co.uk/maps/@51.4007364,-0.5377096,1751m/data=!3m1!1e3
Do you call them
turbine or
whirlpool interchanges? CBRD (http://goo.gl/C1k2nw) refers to them as the latter, though the former is more common in the US.
SR 202 @ i295 in Jacksonville FL(https://www.aaroads.com/forum/proxy.php?request=http%3A%2F%2Fuploads.tapatalk-cdn.com%2F20160804%2F924446e20009e612c0f47b7c0e76fc67.jpg&hash=06a67cb52ec36e4cfd1f39797bded663527de92d)
Back when I was going to University of North Florida( campus is NE corner) it was a simple diamond, i295 was St John's Bluff Rd
If you look you can see the remnants of the diamond
There's one proposed for I-80 at I-380/US 218/IA 27 in Coralville, Iowa: Link. (http://www.iowadot.gov/pim/documents/092915I80JohnsonPD2.pdf)
I-55 at I-355 in Chicagoland is a 3/4 turbine: Google Aerial (https://www.google.com/maps/@41.7045832,-88.0299302,1669m/data=!3m1!1e3?hl=en)
I would be curious though if there are more stack-turbine hybrids than full or 3/4 turbines. The St. Louis area has two (I-70 at I-270 (https://www.google.com/maps/@38.7482347,-90.4400345,1744m/data=!3m1!1e3?hl=en), I-270 at US 40 (https://www.google.com/maps/@38.6385972,-90.4486865,873m/data=!3m1!1e3?hl=en)).
As for my opinion of the design, I generally prefer stacks. The turbine design generally does not seem to provide much higher ramps speeds than a stack, usually ends up taking up similar or greater ROW amounts than a stack, and usually ends up with a decent amount of bridges anyway. The only real savings appears to be keeping the interchange height down - which the I-270/I-70 hybrid and I-55/I-355 3/4 turbine don't seem to succeed at. However, I will take a turbine design over a design with lower speed loop ramps and/or weaving.