Interstate 189 crossing over US 7 in Burlington?

[shadyjay]

I've seen a very old photo of the present western terminus of Interstate 189 (Vermont's only 3DI) with US 7.  The photo shows US 7 North with Interstate 189 crossing OVER US 7:
http://lh4.ggpht.com/_LdJssxlEuTQ/TFDpd2tcylI/AAAAAAAALL8/hornt2zCTqs/LS07898_000_thumb_2.jpg


The present day configuration of the area can be seen here:
https://www.aaroads.com/northeast/vermont100/i-189_wb_exit_001_01.jpg

In that photo, the bridge in the distance is US 7, crossing OVER I-189.  


So why on earth was it changed from US 7 crossing under I-189, to US 7 crossing over I-189?  Did it have something to do with the since-cancelled "Southern Connector" which would have continued I-189 west, then north along Lake Champlain into downtown Burlington?  A portion of this connector was built (and has never been open, though there are plans to open parts of it).  Going through that area its hard to believe the overpass/underpass situation was reversed - that must've been quite the project back in the day to reverse the overpasses.  

[Alex]

It was originally built with I-189 traveling over U.S. 7. See this map, which we created based upon the 1965 Greater Burlington Urban Area Highway Plan book we found at the University of Vermont library
A lot of what we discovered I added to our Burlington guide:

Two plans for western extensions of Interstate 189 existed since the highway opened on November 29, 1962. The first extension was short in nature, taking Interstate 189 west to a trumpet interchange with the unconstructed Burlington Belt Line freeway. In 1979, Interstate 189 was planned to turn northwest along the Southern Connector, a freeway between U.S. 7 and the intersection of Battery and Maple Streets southwest of downtown. Neither extension was completed, but the 1979-plan did result in the building of an unopened four-lane parkway northwest to Home Avenue two blocks west of Pine Street.

So the change must have happened by 1979.

[agentsteel53]

I've seen a very old photo of the present western terminus of Interstate 189 (Vermont's only 3DI) with US 7.  The photo shows US 7 North with Interstate 189 crossing OVER US 7:
http://lh4.ggpht.com/_LdJssxlEuTQ/TFDpd2tcylI/AAAAAAAALL8/hornt2zCTqs/LS07898_000_thumb_2.jpg

interesting; here's a variant of that with the same overpass configuration, but a different 7 shield.  I wonder what the absence of the cardinal direction in this photo means.



photo taken 6/18/1966.

[Alps]

Two plans for western extensions of Interstate 189 existed since the highway opened on November 29, 1962. The first extension was short in nature, taking Interstate 189 west to a trumpet interchange with the unconstructed Burlington Belt Line freeway. In 1979, Interstate 189 was planned to turn northwest along the Southern Connector, a freeway between U.S. 7 and the intersection of Battery and Maple Streets southwest of downtown. Neither extension was completed, but the 1979-plan did result in the building of an unopened four-lane parkway northwest to Home Avenue two blocks west of Pine Street.

Sounds like it was the connection to the proposed parkway that resulted in the freeway being depressed instead of elevated.

[Alex]

Two plans for western extensions of Interstate 189 existed since the highway opened on November 29, 1962. The first extension was short in nature, taking Interstate 189 west to a trumpet interchange with the unconstructed Burlington Belt Line freeway. In 1979, Interstate 189 was planned to turn northwest along the Southern Connector, a freeway between U.S. 7 and the intersection of Battery and Maple Streets southwest of downtown. Neither extension was completed, but the 1979-plan did result in the building of an unopened four-lane parkway northwest to Home Avenue two blocks west of Pine Street.

Sounds like it was the connection to the proposed parkway that resulted in the freeway being depressed instead of elevated.

From what I gather, it was elevated above US 7 originally as they thought it would travel a short distance west and tie into the unconstructed Belt Line. Once that concept was abandoned, which was not too long after 1965, they came up with that Southern Connector concept and subsequently redid the interchange. I also remember reading in documents there about issues with right of way because of that adjacent shopping center. There are tight quarters along the north side of the interchange:



Andy and I walked along the dead Southern Connector roadway in 2007 and all around the interchange. Unfortunately in the three years since we took these photos, we have yet to post any of them!

[froggie]

According to the National Bridge Inventory, the existing bridge was built in 1988.  Probably tied to when US 7 was made 4-lanes divided (instead of the earlier undivided) through the area due to commercial development.

It should also be noted that the now-Microsoft Research Maps (formerly Terraserver) topo map is dated 1987 and shows the original trumpet configuration with 189 bridged over 7.

[shadyjay]

Wow - very interesting.  Hard to believe it was all done for a highway project that never was finished (though its not unusual for New England states to undertake such a project for a project that gets cancelled - re:  I-84/Rt 9 "Stack" in CT).  For Vermont standards, that must've been quite the project when I-189 was lowered.