Environmental Assessment

The project team has completed the Environmental Assessment and has moved into the construction phase.

I-25 South Gap: Monument to Castle Rock Environmental Assessment

In June 2018, CDOT and the Federal Highway Administration (FHWA) completed the National Environmental Policy Act (NEPA) analysis for the I-25 South Gap Project. The FHWA provided the final approval for the project to move to final design and construction.

In May 2018, CDOT and FHWA released the I-25 South Gap: Monument to Castle Rock Environmental Assessment (EA) for public comment. In June 2018, the FHWA issued the Finding of No Significant Impact, which approved the planned project for construction and responded to public comment on the EA.


Preferred Alternative:

CDOT proposed expanding I-25 between Monument and Castle Rock by:

  • adding a new tolled Express Lane in each direction;
  • widening shoulders;
  • replacing outdated infrastructure;
  • addressing design deficiencies of the aging roadway;
  • adding wildlife underpasses; and
  • modernizing the facility with improved drainage, lighting, communications, power and signage.

All improvements are planned within CDOT's right of way; no property acquisition is anticipated.


EA Review:


Public Hearings & Responses

Members of the public were invited to attend public hearings to provide input on the proposed project and EA conclusions. CDOT presented the preferred alternative for the I-25 South Gap Project, findings of the EA, and information about the next steps in the project schedule. Two public hearings for this project were held in Castle Rock and Colorado Springs.

CDOT and FHWA reviewed and considered all comments. Through this process, CDOT and FHWA decided to move forward with the preferred alternative. All comments received during the comment period, including at the hearing, are part of the project record and received a written response, which is included with the Finding of No Significant Impact (FONSI) report.