I-70 West Vail Pass Auxiliary Lanes - Design

Photo of trucks and vehicles backed up on highway with clear line in front

Design work started in early 2021 on the first phase of West Vail Pass improvements that have identified funding. These Phase I improvements include:

  • An eastbound I-70 auxiliary lane with widened shoulders between Mile Points 185 and 190
  • Westbound Curve modifications with widened shoulders at Mile Point 186 and 188
  • Bridge replacement eastbound and westbound at Mile Point 185.3
  • Truck ramp reconstruction at Mile Point 182
  • Improved signage and incorporation of Active Traffic Management system
  • Variable speed limit signs
  • Highway closure system
  • Six wildlife underpasses and fencing
  • Vail Pass recreational trail relocation between Mile Points 185 and 187

The project’s contractor Kiewit Infrastructure is assisting in the design development as a part of the construction management/general contractor (CM/GC) delivery method. The initial design focus is on the truck escape ramp and the highway closure system and construction on these components began in August 2021.

In addition to the first phase of improvements with identified funding, work is underway on additional I-70 Mountain Corridor improvements, including the Corridor Aesthetics Guidelines and Corridor Sediment Control Action Plan.

CSS Commitments

As design and construction activities begin, CDOT along with the design and contractor teams will uphold the obligations and mitigation strategies outlined throughout the CSS process and in the Environmental Assessment.

Early commitments met include:

  • Creation of an Aesthetics Issues Task Force responsible for developing project-specific aesthetic guidance.
  • Creation of an Issue Task Force to update the Black Gore Creek Sediment Control Action Plan and identify improvement opportunities for maintenance access.
  • Emergency Planning
  • Initial design of wildlife crossings

During construction the project team will comply with EA commitments to minimize impacts from construction activities

Improvements & Funding Status

Improvements Identified in Environmental Assessment

Phase 1 Improvements (currently funded)

Construction Activities (Started August 2021)

Add a 12-foot auxiliary lane in both directions of I-70 between MP 180 (East Vail) and 190 (Vail Pass Rest Area)

Adding a 12-foot auxiliary lane along eastbound I-70 between MP 185 and 190

Widen inside shoulders to minimum 6 feet between Mile Points 180 and 190 

Widen inside shoulders between MP 185 and 190

Widen outside shoulders at least 8 more feet beyond existing 10 foot width in multiple locations for emergency pull-offs


Modify all exiting curves as needed between Mile Points 180 and 190 to meet federal design standards

Reconstruct three curves between Mile Points 187 and 189

Install additional variable message signs at key locations


Install automatic highway closure gates in both directions of I-70

Install automatic highway closure gate along westbound I-70


Relocate approximately 2 miles of Vail Pass Recreation Trail


Upgrade existing emergency truck ramps at Mile Points 182 and 185

Upgrade emergency truck ramp at Mile Point 182


Build 6 wildlife underpasses and add wildlife fencing


Install additional variable speed limit signs

Add capacity to existing commercial truck parking area at top of Vail Pass

Improve median emergency turnaround locations

Improve existing chain station at MP 182.5

Install avalanche protection near MP 186