Friday, March 20, 2015

Planning For Hartford CT I-84 Reconstruction

One of Connecticut's most heavily used freeway segments, used by some 170,000+ vehicles daily.

I-84 in northwestern Hartford Connecticut is largely upon a viaduct, and feeds into a trenched northern east west segment that is partially lidded.

Recent planning to reconstruct this northwestern segment aims to reconstruct this freeway segment, perhaps radically reconfiguring it to have it fit better within the local landscape.

The freeway options include a more attractive viaduct, with or without a short tunnel segment, a lowered road/trench with the short tunnel segment, or a longer tunnel.

An earlier option to replace this freeway segment with a surface street-boulevard has been abandoned as not meeting the project's needs and in presenting a greater local barrier of the heavy stream of I-84 traffic.

Short Tunnel with Viaduct Segment

Viaduct and Lowered Roadway-Tunnel Options

Complicating this project is the adjacent rail corridor which crosses to the east and then back to the west of the freeway.

Lowering the railroad would be more difficult owing to the requirement to keep the gradient under 1%, and relocating it to the highway's east would  not reduce the number of its crossings with the highway.   However, relocating the railroad to be entirely west of the highway would only require relocating a short stretch of the railroad while eliminating its crossings with this freeway project segment.  Thus, the project might relocate the segment of that railroad to remain upon the highway's western side, though that would thus place the highway between the railroad and the Amtrak station, that could be accommodated with that highway segment as cut and cover.

Baseline—Enhanced Viaduct:
Highway replaced with
enhanced viaduct structure

Alternative Concept 1:
Highway replaced with enhanced
viaduct structure; improved connections across highway- includes short tunnel segment in the vicinity of the Amtrak Station

Alternative Concept 2:
Viaduct replaced by surface roadway; rail line relocated to north side of I-84; city reconnected
across highway- includes short tunnel segment in the vicinity of the Amtrak Station

Alternative Concept 3:
Viaduct replaced by tunnel, including that in the vicinity of the Amtrak Station, but extending southwards past the Aetna Center; rail
line relocated to north side of I-84; city reconnected across highway

Choose either options #3 or #4.

Reconstruct elevated portion of I-91 in tunnel or in trench that is partially lidded as tunnel, and designed to have additional segments subsequently lidded, as per Cincinnati's I-71 Fort Washington Way project.

Although the current official planning merely addresses I-84, there are voices calling for the project to include a short cut and cover tunnel spur to connect with the already constructed Whitehead Freeway, as per the previous proposal for an I-484 Colon Whitehead Connector.

I-484 Tunnel beneath Bushnell Park

Such a connector could be updated by constructing new lids atop the Whitehead trenched freeway, near Pulaski Circle to the west and to Columbus Boulevard to the east.  Lower the Whitehead roadbed to clear the historic overhead crossing so as to provide 2 lanes in each direction.  Or disassemble and reassemble that historic bridge relocated into a new location, and perhaps build the connector with 3 lanes per direction.
I-484/Colon Whitehead Connector
I-484/Colon Whitehead Connector
I-484/Colon Whitehead Connector

Likewise, the ramp connections from the west could be covered as a part of a project reconstructing the adjoining I-84 segment as a lidded- cut and cover tunnel.

Such a connection would be unobtrusive as a tunnel, and serve as a relief route from the northern Hartford CT I-84 segment.

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