US 85 Corridor Improvements (State Highway 67 to County Line Road)

Updated August 1, 2017



In 2002, the Colorado Department of Transportation (CDOT) and Federal Highway Administration (FHWA) completed the South I-25 / US 85 Environmental Impact Statement (EIS) and Revised Record of Decision (ROD) outlining a set of improvements to address transportation needs in the region.  Since then the County has helped provide funding assistance to CDOT for constructing improvements on several segments of US 85.  As additional residential and commercial growth continued to occur, further studies were needed to identify what transportation improvements are necessary to support the development occurring throughout the County.  Accordingly, in the summer of 2015, Douglas County initiated two important studies on the US 85 Corridor. These two studies are separate but were closely coordinated at each step in the process – allowing several opportunities for citizen and corridor stakeholder to provide input.  For more detailed project information visit the project website at

US 85 Corridor Study (PEL Study completed January 2017)

The goal of the recent Douglas County US 85 Corridor Study, known formally as a Planning and Environmental Linkage (PEL) Study, is to update previous corridor recommendations for transportation improvements to US 85 from approximately State Highway 67 in Sedalia to 1/2 mile north of County Line Road.  The study will help the county and other agencies identify the long term transportation needs beyond 2040 – though many of the identified improvements could be implemented much sooner.

As part of the PEL, the project team identified a “Purpose and Need” that focused on addressing traffic concerns (including accidents) to develop the proposed alternatives.  The Corridor Study identified a corridor vision and implementation plan, outlining the environmental clearances and design steps required to build the recommended improvements in the future when needed.

Continuing to improve traffic operations and reconstruct the US 85 / C-470 Interchange are a top priority for CDOT and the County, which is estimated to cost $27 million and $11.3 million in federal funds has been allocated for construction to begin no earlier than spring 2019.

US 85 Early-Action Project (EA Re-Evaluation completed July 2017) 

The goal of this Early-Action project is to update the 2002 Record of Decision (ROD) to address changes to conditions that have occurred since it was issued by the FHWA, and to analyze impacts of recommended improvements for the segment of US 85 from Highlands Ranch Parkway to C-470.  Douglas County was selected to receive $15 million in federal funds via the Denver Regional Council of Governments to help partially fund construction in 2019 of the estimated $58 million needed for the proposed improvements.  The proposed improvements include capacity, operational and safety improvements – which designed to accommodate anticipated traffic volumes in 2040.

The project team anticipates final design will be completed by January 2018.  The next critical step will be to acquire additional right-of-way (ROW) needed to accommodate the widening of U.S. 85 from 4-6 thru lanes, and the need to relocate utilities that are in conflict with the proposed improvements.  ROW acquisition is anticipated to begin in fall of 2017 and continue through the summer of 2018. Engineering staff anticipates utility relocations will begin in 2018 and continue into 2019, which could impact the traveling public.

For more information please contact Art Griffith, (Douglas County Transportation Capital Projects Manager), via email at