I-70 Floyd Hill Preconstruction Studies and Environmental Assessment

Floyd Hill Environmental Assessment Complete

On Aug. 2, 2021, CDOT released an Environmental Assessment (EA) detailing our preferred plan for highway and other improvements to I-70 between Floyd Hill, west of Evergreen, through the Veterans Memorial Tunnels to the eastern edge of Idaho Springs. The 60-day EA comment period ended on October 1, 2021. CDOT and FHWA are reviewing comments and will formally respond to comments received in the decision document, expected in late 2022. In the meantime, information from the EA and virtual public engagement event are available. Although the official comment period is closed, feel free to contact us. We are always happy to hear from you!

Several Early Projects have been advanced for design, with construction expected to begin on portions in Fall 2022. These Early Projects include intersection improvements at CR 65 and Homestead Road on US 40 and wildlife crossings at Genesee and Empire. Visit the Early Projects tab on the left to learn more.

CDOT released Requests for Proposals for design and construction consultants under a Construction Manager/General Contractor (CMGC) delivery method. Visit the Project Delivery page for more information. CDOT selected Kraemer North America as the Construction Manager and Atkins as the Designer. Requests for Proposals for Independent Cost Estimating services and Owner's Representative services are also in process.

The Project Leadership Team (PLT) will continue to guide the next phases of the Floyd Hill Project, including the Early Projects, and oversee the implementation of the I-70 Mountain Corridor Context Sensitive Solutions (CSS) Process.

I-70 Floyd Hill to Veteran Memorial Tunnels Improvements project limits study area map

Environmental Assessment Documents

 Alternatives Considered

The I-70 Floyd Hill to Veterans Memorial Tunnel Project would improve I-70 from Floyd Hill (west of Evergreen) through the Veterans Memorial Tunnels on the eastern edge of Idaho Springs.

The major elements of the project are:

  • Adding a third westbound travel lane to the two-lane section of I-70 from the current three-lane to two-lane drop (approximately MP 246) through the Veterans Memorial Tunnels the new lane would be an Express Lane
  • Constructing a new frontage road between US 6 and the Hidden Valley/Central City Interchange
  • Improving interchanges and intersections throughout the Project area
  • Improving design speeds and stopping sight distance on horizontal curves
  • Adding an auxiliary lane to I-70 in the eastbound (uphill) direction of Floyd Hill between the US 6 interchange and the Hyland Hills/Floyd Hill interchange 
  • Improving the multimodal trail (Clear Creek Greenway) between US 6 and the Veterans Memorial Tunnels
  • Reducing animal-vehicle conflicts and improving wildlife connectivity with new and/or improved wildlife overpasses or underpasses
  • Providing two permanent air quality monitors at Floyd Hill and Idaho Springs to collect data on local air quality conditions and trends
  • Coordinating rural broadband access with local communities, including providing access to existing/planned conduits and fiber in the interstate right of way

Two alternatives are under consideration for adding the third lane of capacity along westbound I-70 between US 6 and the Hidden Valley/Central City Interchange:

  1. The canyon viaduct alternative (preferred) would construct a viaduct structure and elevate both the eastbound and westbound lanes of I-70 through the Clear Creek Canyon. The existing I-70 highway under the new bridges would be used for the frontage road and Greenway. The video below provides more detail about the preferred alternative.

  2. The tunnel alternative would construct a tunnel that would carry three lanes in the westbound direction of I-70. Eastbound I-70 would be realigned on the exiting highway footprint to flatten curves. This alternative also includes two options for the alignment of the new frontage road on either the north or south side of Clear Creek. Two design options were considered for the frontage road alignment under the tunnel alternative. The North Frontage Road option would locate the new frontage road on the north side of Clear Creek. The South Frontage Road Option would locate the frontage road on the south side of the creek. The video below provides more detail about the tunnel alternative.