I-25 & Mulberry Interchange Improvements | Design & Planning Phase

About the Study

The I-25 and Mulberry Street (Colorado Highway 14) interchange, situated in Fort Collins, Larimer County, has been under consideration for transportation improvements since 2003. Initially part of the I-25 North Express Lanes Project, there have been delays in improvements due to funding challenges and complex issues specific to the interchange. Since the completion of the I-25 North Express Lanes Project, the interchange improvements were incorporated into CDOT’s 10-year plan. In September 2022, the project secured approval for design funds. Proposed improvements will address unconventional traffic operations, flooding concerns and aging infrastructure.

As of August 2024, construction for this project is not yet planned, as construction funding has not been identified. The Colorado Department of Transportation and project partners will continue looking for funding opportunities as part of the design and public involvement process.

Project Area

This project is located on I-25 North, between Mile Point (MP) 269 and MP 271. This includes the Mulberry Street interchange and the frontage road connections in Larimer County and the City of Fort Collins (for approximately one mile along CO 14, from MP 138.7 to 139.25).

Schedule & Important Dates

  • Final interchange concepts prepared - Mid-2025
  • 30% Design – Early 2026
  • 60% Design – Early 2027
  • Final Design – Early 2028

Note: 60% and final design timeframes are an estimate, but unknown construction funds, and environmental, utility and right-of-way impacts may change these estimates greatly.

The overarching goal for this project is to progress the design and reach a proposed, constructable interchange alternative. As part of this design development, CDOT will coordinate with stakeholders and the public to ensure the full reconstruction of the interchange supports regional transportation improvements with an economically feasible design. Additional goals include: enhancing vehicle and pedestrian safety, securing construction funds, supporting current and future transit connections, improving vehicle/bicycle/pedestrian traffic flow, and modernizing the project site for electric vehicles.

Once construction funding is secured and construction complete, this project will provide the following benefits to this section of I-25 in northern Colorado:

  • Improved traffic and access operations
  • Improved safety
  • Improved pavement
  • Consideration for improved bicycle and pedestrian facilities
  • Consideration for improved access to transit facilities
  • Bridge replacement
  • Flood mitigation improvements

Results from the evaluation of interchange options will be available once the planning and initial alternatives analysis is complete.