I-25 Central Planning & Environmental Linkages (PEL) Study

The I-25 Central PEL study is complete.

Read the I-25 PEL Study Report

About the Project


Between fall 2017 and winter 2020, CDOT conducted a Planning and Environmental Linkages (PEL) Study of I-25 between Santa Fe Drive and 20th Street. This 4.5-mile segment of I-25 is Colorado's primary urban transportation core. It is utilized for trips through the area and to regional and local connections, including downtown Denver employment, commerce, entertainment, and residences. The study identified causes of congestion and considered options to improve safety, travel time and reliability in this highly-congested corridor. A range of improvements are being evaluated and prioritized for future project development. The study also included the evaluation of environmental impacts, coordination with federal, state, and local agencies, and public involvement.

I-25 Traffic with direction signs above

"The study developed a vision for this 4.5-mile section of I25, using future traffic projections that reflect anticipated growth and possible advances in technology."

What did we accomplish?

The PEL study provided a clear understanding of the transportation problems in the corridor, a collaboratively-developed vision for the future, and potential projects to implement that vision. The study serves as an aid in the development of future projects through the National Environmental Policy Act (NEPA) and design processes. The PEL accomplished the:

  • Identification of corridor needs and a corridor vision
  • Development of alternatives to meet the needs and vision of the corridor
  • Evaluation of potential improvement projects