Partial Y interchange built over a diamond?

[bugo]

http://goo.gl/maps/E3UBE

Note that the ramps from I-40/US 270 to old I-40/US 270 were built right on top of the diamond interchange at Agnew.

[pianocello]

My first thought when I saw this title was the new northern I-39/US-51/STH-29 interchange in Wausau, WI. It's close, but it's a full semi-directional T instead of a partial Y.

https://goo.gl/maps/TbHAE

[Revive 755]

* I-470 at US 75 in Topeka, KS, also qualifies. Google aerial

* I-29 at NW 120th Street near the Kansas City Airport - really strange since the partial Y leads to the same place as the diamond, yet the diamond does not have any turn prohibitions for the movements the partial Y replaces.
Google aerial
Streetview from NB exit of diamond
Streetview at the SB diamond ramps

[roadman65]

The soon to be Airport Boulevard and TOLL FL 417 near Orlando, FL will be one.  It's being built over Exit 17 of TOLL FL 417 which has always been a diamond.

[mgk920]

Howabout US(I)-41/US 45/Algoma BD (Algoma Interchange) in Oshkosh, WI?

http://goo.gl/maps/7Ci4i
(Image shows it under construction in 2012).

Also, WisDOT is piggybacking a full directional 'T' over a conventional diamond at US(I)-41/WI 29/32/Shawano Ave (Shawano Interchange) in the Green Bay, WI area (Howard, WI).  Construction should be complete by the end of the year.

Mike

[Roadsguy]

I thought of this interchange between US 119 and PA Turnpike 43 is a full Y built over the original diamond with PA 51, not connecting to it at all. Not even any of the ramps are shared. Another full diamond just north on 43 serves as the 43-to-51 movements.

The northern end of I-495 at the PA/DE state line is an actual example, though. I didn't know these were called "partial Y"s.

[Brandon]

The split between the Tri-State (I-294) and the Edens Spur (I-94) with the exit for Lake-Cook Road built later:
https://maps.google.com/maps?hl=en&ll=42.152873,-87.872858&spn=0.018135,0.042272&t=h&z=15

[Henry]

Wow, I never thought it could be done! Sure, I've seen interchanges built over water, but literally not on top of another.

[briantroutman]

Wow, I never thought it could be done! Sure, I've seen interchanges built over water, but literally not on top of another.

That's basically the case at the Eisenhower Interchange where I-83, I-283, US 322, and Eisenhower Boulevard meet. There's a partial cloverleaf on what once was Bypass US 230, and then a directional Y connecting I-83 and I-283 was layered on top of it.

[Michael]

The upgrade of the interchange of I-86/US 15 is a semi-directional T on top of a diamond with one ramp folded on I-86.

[sbeaver44]

Scott Depot, WV:  I-64/US 35/CR 33.

With slight bending of the rules:

State College, PA:  I-99 Exit 73 (US 322 E and Park Dr)