I-25 / Cimarron Street Interchange Improvement, Colorado, United States of America


Cimarron Street improvements

The I-25 / Cimarron Street (US 24) Interchange design build project is an interchange improvement project to be implemented on the US National Highway 24 West in Colorado Springs, Colorado, US.

The I-25 between Colorado Avenue and Nevada Avenue/Tejon Street interchange is one of the busiest interchanges in the Colorado region as it is accessed by more than 150,000 vehicles each day. The interchange is being revamped to ensure overall safety and smooth functioning of the traffic in the area.

The project is sponsored by the Colorado Department of Transportation (CDOT) and the US Federal Highway Administration (FHWA). A team of Kraemer North America LLC and Tsiouvaras Simmons Holderness (TSH) was selected by the CDOT after a rigorous selection process, to reconstruct the interchange.

The pre-construction and mainline construction of the project started in 2015 and March 2016, respectively, and is scheduled to be completed before December 2017.

Purpose of the I-25 Cimarron Street interchange improvements

The need for the I-25 interchange improvement was recognised by the CDOT in 2004, but no funding was allocated for the project that year. The design team worked in collaboration with local community and received inputs from the regional commuters, neighbourhood residents, local business community, federal agencies and others using the context sensitive solutions (CSS) approach, to understand their needs in order to successfully improve the interchange.

Based on the CSS approach, the team arrived at the decision to upgrade the interchange at 21st Street without causing damage to the historic Midland Terminal Railroad Roundhouse. Additionally, the US 24 will be elevated to pass over the Ridge road.

As a part of the conclusion derived, the ridge road will be reconstructed as the part of the project, while providing a connection between Open space and Midland trail. A new quadrant cut-off road will also be constructed between 8th Street and US 24.

Construction details

The project will include construction and reconstruction of a number of bridges and gateways, which will reflect the heritage of the area.

A bridge will be constructed on the 15th Street to connect Gold Hill Mesa with Colorado Avenue. The west bound exit ramp to 15th Street will have an 1,800ft sound wall and will be constructed parallel to the ramp.

A major travel corridor connecting US 24 with northern points, 31st Street will be improvised with flora along the Fountain Creek and with Xeric informal landscaping on the south side. The street will also see a new stone veneer bridge over the Fountain Creek. Swales will be constructed adjacent to the highway in order to prevent run off from entering Fountain Creek.

The old Colorado city gateway on 26th Street will see additions such as placement of the Miners statue, and planting of trees and shrub masses.

"The project is sponsored by the Colorado Department of Transportation (CDOT) and the US Federal Highway Administration (FHWA)."

A trestle design pedestrian bridge with two sections will be built on 25th Street. The first segment will be spread across the highway for connecting the elevated trail with the north of US 24, while the second will be built from Fountain Creek to offer users access to 25th Street.

All vehicular bridges will be based on Victorian theme. The bridges will be arch-shaped with natural stone veneer exteriors, which will be used to reflect a historic stone bridge image.

The sound and retaining walls, with a 100-year flood plan, will be constructed using concrete and stamped grid pattern to provide privacy and prevent noise pollution from vehicles on the US 24.

The project will also focus on improving the roadway shoulders by using dry land grasses alongside, xeric paintings and native grasses. The swales will be decorated with herbaceous plants and grasses.

Financing

The total investment estimated for the project is $113m, which has been sourced through federal and state funds.

The City of Colorado Springs and El Paso County are funding a part of the investment.

Key players involved

Wilson & Company assisted in preparing the conceptual design and documentation of the project.

THK Associates is responsible for designing landscaping and structural aesthetics of the structure, in addition to being owner's representative for CDOT.