CDOT’s Floyd Hill project expected to begin this summer

CDOT’s revised plan for the Central City Parkway Exit on I-70 (Exit 243). The building on the left is Black Hawk’s Hidden Valley water treatment plant. Near the center is the existing Squatch Store and gas station. (Image courtesy of CDOT.)

By Don Ireland
Weekly Register-Call
Senior Reporter

The proposed $700 million I-70 expansion program for Floyd Hill is inching closer to reality. CDOT leaders say the first phase could begin late this spring for the main project, which could potentially impact lucrative casinos and tourist traffic for Black Hawk, Central City and Gilpin County.

U.S. Transportation Secretary Pete Buttigieg, Colorado Gov. Jared Polis and other federal and state leaders held a press conference to discuss the Floyd Hill project on Feb. 24, 2022. In the year that’s followed, Colorado Department of Transportation (CDOT) leaders have developed a series of plans for the I-70 mountain corridor – some of which have already begun.

The Floyd Hill project encompasses and eight-mile stretch of I-70 from west of Genesee to the Memorial Tunnels east of Idaho Springs. The work will include changes to Exits 244 and 243, which are heavily-used by motorists heading to Black Hawk, Central City and other parts of Gilpin County. Traffic restrictions are expected along the highway but Highway 6, also known as “The Canyon” will remain open to traffic from Golden to near Black Hawk.

The largest part of the highway-improvement plan calls for adding one extra traffic lane on Floyd Hill, which frequently becomes heavily congested during peak travel times for Denver and Front Range residents heading into the mountains. Kraemer North America is the contractor for the project.

According to CDOT, final plans should be completed in April for the main portion of the Floyd Hill project, with work anticipated to begin in May. The work, anticipated to be completed in 2028, will include:

Adding a third westbound travel lane in this two-lane bottleneck of I-70. The new lane would be a tolled “Express Lane,” similar to the one that begins at the Veterans Memorial Tunnel east of Idaho Springs.

Constructing a missing two-mile section of the frontage road between Evergreen and Idaho Springs.

Adding an eastbound auxiliary lane to reduce conflicts with slow-moving freight and other vehicles in the uphill section of Floyd Hill.

Improving traffic flow and access at interchanges and intersections.

Improving design speeds and stopping sight distance on horizontal curves.

Improving the Clear Creek Greenway trail.

Implementing environmental mitigation to enhance wildlife connectivity, air and water quality, stream conditions, and recreation.

Since the original reconstruction program was announced, there have been several changes, according to CDOT. They include:

Shifting I-70 westbound alignment north to bottom of existing slope (closer to US 40 and Clear Creek) to improve construction access.

Relocating U.S. 6 access onto westbound I-70 to the Hidden Valley/Central City Parkway interchange.

Realigning eastbound and westbound elevated portions of I-70 over Clear Creek Canyon to separate alignments with a terraced hillside cut, rather than parallel viaducts with a larger hillside cut. Eastbound I-70 is still elevated but lower than the earlier concept and returns to existing grade near U.S. 6.

Realigns an approximately 1,600-foot section of Clear Creek south near the Hidden Valley/Central City Parkway interchange (instead of a similar creek realignment in the West Section).

CDOT said there have been changes to the proposed work between Exit 243 (the Central City Parkway) and Idaho Springs. They include:

Concentrating widening for the new westbound travel lane on north side of Clear Creek Canyon. More rock excavation will happen next to westbound I-70, but no rock excavation will happen on south side of Clear Creek Canyon.

Avoiding impacts to County Road 314, which will remain open during construction, and Clear Creek.

New impacts to an archaeological site, which will require a treatment plan and
memorandum of agreement with the State Historic Preservation Office.

In January, CDOT reported the Federal Highway Administration (FHWA) signed a “Finding of No Significant Impact” environmental assessment report for the I-70 Floyd Hill project. 

Two smaller, related projects are already underway along I-70. They include construction of a $10 million wildlife underpass at Genesee, near mile marker 254.5, and a $9 million project that will create two traffic roundabouts on U.S. 40, At the intersections of County Road 65 and Homestead Road in Clear Creek County.

CDOT also plans to spend between $7 and $10 million to build a wildlife crossing area beneath I-70 at Empire – west of Idaho Springs – beginning later this year. The bridge will be near mile marker 257. Wildlife fencing also will be installed along both sides of U.S. 40 in the area in an effort to reduce the number of collisions between bighorn sheep herds in vehicles.