US 85 from I-76 to 124th Avenue: Highway Design Improvements

Starting in June 2017, a team began considering improvements to US Highway 85 from Interstate 76 to 124th Avenue in Adams County. The team—which includes CDOT, the Federal Highway Administration (FHWA), Adams County, Commerce City and the cities of Thornton and Brighton—is working on preliminary design; there will be no traffic impacts during this phase.

Purpose & Need

This work is intended to:

  • improve safety;
  • reduce existing and future traffic congestion;
  • improve connectivity for and between transit (bus), bicyclists, and pedestrians;
  • improve regional mobility for cars, freight movement (truck and rail), and transit (bus); and
  • provide efficient access for existing and future land use.

The team identified safety, vehicle and transit (bus) operations, bicycle and pedestrian connectivity, and regional mobility and access control as elements the conceptual design will strive to improve upon and achieve.


Current work includes:

  • Developing alternatives to analyze existing and future traffic patterns, property impacts, and overall feasibility using the purpose and need statement
  • Meeting monthly to review and provide input on the system alternative design, evaluation and selection (Parties include members of local and regional jurisdictions and interested agency/organizations.)

Upcoming Work includes:

  • Evaluating alternatives by conducting a three-tier screening process, resulting in a preferred alternative—including priority phasing
  • Performing additional traffic analyses to develop to a 30 percent level to further identify anticipated construction costs


  • Design Completion: December 2017
  • Design Approval, Phasing & Alternative: Spring 2018
  • Final 30 Percent of Design: Summer 2018
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