top of page

I-25 South Gap

In 2016, the Colorado Department of Transportation (CDOT) began the Planning and Environmental Linkages (PEL) Study and Corridor Implementation Plan for the 34-mile section of I-25 between Monument and C-470 and ultimately narrowed its focus on the segment between Monument and Castle Rock known as “The Gap.” This 18-mile stretch of interstate is the only four lane segments between Denver and Colorado Springs, creating a bottleneck of congestion that has increased delays and traffic incidents. CDOT partnered with El Paso and Douglas Counties and the Pikes Peak Rural Transportation Authority to fund the $350 million widening project.

The PEL Study analyzed and addressed safety, travel reliability, and mobility issues through the corridor. It identified, defined, and prioritized the projects, evaluated environmental constraints, and clarified projects costs. The PEL included field survey, environmental services, and the geotechnical investigation to be used in the subsequent design phase of the project.

The South Gap project adds one Express Lane in

each direction alongside the existing general-purpose lanes to increase total capacity and relieve congestion. The Express Lane offers choices for motorists and promotes carpooling and other environmentally conscious modes of travel.

RockSol geotechnical engineers developed a drilling program as part of the investigation, understanding the history of corridor improvements since the late 1940s. The majority of mainline I-25 roadway pavement section within the project limits consisted of flexible hot mix asphalt (HMA) over Portland cement concrete pavement (PCCP) within the drive lanes with asphalt shoulders. The team also provided preliminary pavement design recommendations for the Douglas County cross roads that would be reconstructed as part of the project. RockSol's structural engineering team designed 3 bridges, approximately 1.5 miles of MSE wall, and one soil nail wall as part of our efforts. 

In 2018, RockSol was selected to provide the construction management services for the project, including CMGC support services and construction administration. The RockSol team assisted CDOT with selecting eCostruction software and developing project control processes to enable smooth delivery. The work also includes coordinating with CDOT and Kraemer to ensure that the project is delivered per CDOT’s standards and specifications.

bottom of page