US 85: I-76 to 124th Avenue

Study Timeline

  • Environmental Documentation: Spring 2020
  • Final Engineering Design Starts: To Be Determined

When funded, construction may be within 24 months.

Study Area and Vicinity figure (2).jpg

CDOT and the Federal Highway Administration (FHWA)—in coordination with Adams County, and Commerce City, Thornton and Brighton—have been considering and discussing transportation improvements to US Highway 85 from I-76 to 124th Avenue in Adams County.

This advisory team has reviewed and evaluated preliminary system alternatives to best improve the transportation network and the US 85/104th Avenue, US 85/112th Avenue, US 85/120th Avenue, and the US 85/124th Avenue intersections.

On March 20, 2018, the advisory team gathered public input on several alternative interchanges for: US 85/104th Avenue, US 85/112th Avenue, and US 85/120th Avenue and US 85/124th Avenue. This input helped the advisory team refine the proposed action to best meet the purpose and need, and to be responsive to public needs, as well as community and environmental resources.

US 85 Proposed Action

The alternatives development and evaluation process consisted of a three-level iterative process. The advisory team has identified a Proposed Action for further evaluation in the Environmental Assessment. The Proposed Action includes the following proposed transportation improvements:

  • Closure of the existing at-grade US 85/124th Avenue signalized intersection;

  • Replacement of the existing at-grade US 85/120th Avenue intersection with a grade-separated diverging diamond interchange (DDI);

  • Extension and addition of left and right-turn lanes on 112th Avenue at the existing at-grade signalized US 85/112th Avenue intersection;

  • Installation of rumble strips on the right and left shoulders, centerline cable barrier, additional lighting, and reflective signal backplates at the US 85/112th Avenue intersection, as appropriate;

  • Closure of the existing at-grade unsignalized US 85/Longs Peak Drive ¾ movement intersection;

  • Replacement of the existing at-grade signalized US 85/104th Avenue intersection with a grade-separated diamond interchange; and

  • Extension and addition of left and right-turn lanes at the existing 104th Avenue/Brighton Road and 120th Avenue/Oakland Street intersections.

What is the Purpose of the Transportation Improvements?

The purpose of the proposed transportation improvements in the US 85 corridor from I-76 to 124th Avenue are to:

  • Improve safety;
  • Reduce existing and future traffic congestion;

The goals of the proposed transportation improvements in the US 85 corridor from I-76 to 124th Avenue are to:

  • Improve connectivity for and between transit (bus) bicyclists, and pedestrians; and
  • Improve regional operations for cars, freight, and transit (bus), along US 85 between the Denver metropolitan area and communities in Adams and Weld Counties and provide reasonable access for existing and future land use.

Why are the Transportation Improvements Needed?

  • Safety - There is a higher than expected number of rear-end crashes at the US 85/104th Avenue and US 85/120th Avenue intersections. The proximity of the railroad to the intersections is not adequate to safely accommodate queues that form between the railroad tracks and US 85 when a train is present.
  • Vehicle and Transit (Bus) Operations - Traffic operations along the corridor and at the intersections are congested today and are expected to worsen by 2040 due to local and regional population and employment growth.

Most Recent work includes:

  • Completion and review of Environmental Assessment (NEPA)
  • Completion of 30% engineering

Current work includes:

  • Finalize Environmental Assessment (NEPA) document for publication

Upcoming Work includes:

  • Environmental Assessment (NEPA) pulication and final public meeting

TIMELINE:

  • Environmental Documentation: Spring 2020
  • Final Engineering Design: To be determined

When funded, construction may be within 24 months.