Denver South presents Constructing the Future – CDOT Region 1


On October 6, Arapahoe County Commissioner and Denver South Board Member Nancy Sharpe opened the Denver South partnership meeting at the Lone Tree Arts Center by reminding the business and government leaders attending about some of the organization’s accomplishments. She told them, “Denver South and its jurisdictional partners have leveraged in excess of $400 million in transportation investments,” including the Southeast Light Rail extension into RidgeGate, Arapahoe and I-25 interchange, RidgeGate Parkway improvements, Lone Tree Link, Lone Tree On Demand service, and the Smart Yosemite Corridor project that coordinates traffic signals through three cities (Lone Tree, Centennial and Greenwood Village) and two counties (Douglas and Arapahoe).” 

Stephanie Alanis, CDOT Region 1 South Program Engineer, Professional Engineer III

Sharpe introduced Stephanie Alanis, CDOT Region 1 South Program Engineer, who oversees CDOT projects in Arapahoe and Douglas Counties. 

Alanis told the group that CDOT Region 1 is responsible for state-maintained roads from east of Denver west to the I-70 Eisenhower Johnson Memorial Tunnel, that cover eight counties and 60 local jurisdictions serving 2.9 million people, which is half the state’s population. They maintain 4,200 lane miles on which vehicles travel an average of 38 million miles each day. Their work includes pavement, striping, signage, snow removal, operations, and capital improvements on roads that have 912 bridges, 2.5 million feet of guardrail, 376 traffic signals and over 100 miles of sound walls. 

Central 70 is the most well-known regional project currently underway by CDOT and its partners. It is a $1.2 billion reconstruction of 10 miles of I-70 between Brighton Boulevard and Chambers Road that sees over 200,000 vehicles daily. The work includes a new express lane is both directions, removal of a 57-year-old viaduct, and placement of a four-acre park over part of the lowered interstate between Brighton Boulevard and Colorado Boulevard. Kiewit Meridiam Partners in the contractor for Central 70, which is in the final stages. 

This shows the location of the new Crystal Valley interchange in Castle Rock.

The express lanes on CDOT Region 1’s largest-area project, the I-25 South Gap, were opened a year ahead of schedule. Final completion, including new pavement, wider shoulders, five rebuilt bridges, and four new wildlife crossings, along with 28 miles of deer fencing, will be finished this year. The total project cost was $419 million. 

CDOT is also constructing I-25 mobility hubs, a ten-year project, starting with two new transit stations in partnership with the City of Lone Tree and the Town of Castle Rock. The Lone Tree hub will be located between Sky Ridge Hospital and Lincoln Avenue. Both locations will serve to connect travelers to cities along the I-25 corridor where they can use Bustang’s (CDOT’s express bus) South Line and DTC service. 

Further west, CDOT is working on improvements to US 85/Santa Fe. The $100 million project, in partnership with Douglas County, is a widening and rebuilding of 2.5 miles of US 85 near Town Center Drive and Highlands Ranch Parkway, including bridge replacements, starting this fall, and expected to be completed in three years. It includes a shared-use path and High Line Canal Trail improvements. 

Bustang is CDOT’s intercity and interregional express bus service.

Alanis’ group also just completed a $24 million project this past summer to widen 2.5 miles of US 85 to four lanes from two lanes from Louviers to Sedalia. It included a new bridge, improved access to side streets, and new wildlife fencing. 

In partnership with the Cities of Lone Tree and Castle Pines, and the Town of Castle Rock, CDOT is helping improve the Lincoln Avenue and I-25 and Happy Canyon interchanges and construct a new interchange at Crystal Valley. Alanis explained that the local agencies are running these projects and CDOT “is helping with the transportation demand management, the reduction of greenhouse gases, and strategizing how to make these improvements, but also, not preclude other modes of transportation.” She described the new Crystal Valley interchange as a way of “trying to stay ahead” of the impact to the Plum Creek interchange of expected new development. Significantly, it will include the relocation of the west frontage road, which has “four at-grade rail crossings” that present safety concerns. 

An exciting project now being planned is I-70 Floyd Hill. Major construction is planned to begin in summer 2023 to revamp eight miles of I-70 between Evergreen and Idaho Springs, notorious for its lengthy back-ups, particularly during ski season. The cost is estimated at $700 million. 

CDOT-Kiewit Central 70 project

Alanis concluded her presentation by pointing to CDOT’s 10-Year Plan that guides priorities within a $4 billion curated list of statewide projects. All require extensive public input before they are finalized and all must comply with new greenhouse gas reduction requirements.

Finally, she pointed to the basic rules that apply to all CDOT projects. They must 1) maximize safety; 2) be resilient, allowing roads to remain open and functional, regardless of weather; 3) have “fix it first,” which refers to the policy that every project must include an evaluation of whether something can be fixed, rather than replaced; 4) multimodal, meaning that there must be projects that involve transportation in other than single-occupancy vehicles.