WB Widening


The Twin Tunnels Westbound Bore widening project is needed as part of the long term minimum program of improvements as described in the I-70 Programmatic Environmental Impact Statement and Record of Decision completed in June 2011. The project is located on Interstate 70 from milepost 242.3 at East Idaho Springs to milepost 242.83 near the Hidden Valley Interchange. The limits of the work include County Road 314 from structure CLR314‐W0.7 to just west of the Interstate 70 Hidden Valley Interchange at milepost 243.00.  County Road 314 will be used as a detour during the widening of the westbound bore of the Twin Tunnels. The project is located within the City of Idaho Springs, Colorado in Clear Creek County. CDOT can capture cost efficiencies and greatly reduce future traffic impacts if they can continue with design and construction concurrently with the EB tunnel project.  If the westbound tunnel construction can occur in 2014, it can likely be completed in one construction season rather than two.



Aerial Survey Data

Bid Tabs

Final Specs/Plans

Geo Baseline Report

Selection Matrix

Subsurface Investigation

I-70 As-Builts and As-Constructed Plans

I-70 Historical Geotechnical Documents

WB Bore Project PLot

2011 Woolpert Survey - 1GB file - May take several minutes to download

Twin Tunnels WB Bore Widening Pre-Preposal Meeting Roster

Preproposal Meeting WB TT 11072013 - final

Tunnel Form and Rebar Gantry Documents

Twin Tunnels Representative photos Ground Support



I-70 WB Tunnel Preliminary Mapping - Information Only