With the goal of improving safety, operations, and level of service, Muller was tasked with upgrading aging roadway to current standards by widening shoulders and improving horizontal and vertical alignment. The previous rural, two-lane roadway traversed the mountainous terrain of Gunnison and Montrose counties with winding roads and steep grades. For about 2.5 miles, the roadway traverses Blue Creek Canyon where steep rock cuts are present on one side of the roadway with Blue Creek on the other side.

The Muller team used an innovative technique to for a feasibility study for the Blue Creek Canyon portion of the road by conducting a facilitated design charette. We considered alternatives to widen the road and mitigate very sharp curves, rock fall, and clear zone issues in the canyon.

The group vetted various types of cantilevered structures, retaining walls (cantilevered and MSE walls), rock cut strategies, bridges, and tunneling during the feasibility study/design charette. The team’s recommendations for the most cost-effective design approaches and phasing of the corridor construction were presented to the senior management of CDOT Region 3.

There is a major land slide near a CDOT sand/salt dome near the middle of the project. Yeh and Associates conducted extensive geotechnical investigations and developed design recommendations to mitigate the slide to stabilize the road. Based on design team recommendations, CDOT constructed an innovative system using Lightweight Expanded Polystyrene Fill (EPS) to stabilize the landslide. The fill reduces loads on the unstable materials below the mountainside roadway. Along an adjacent segment of roadway, over 100 four-foot diameter coupled shear piles are being drilled into bedrock to mitigate landslide movement.

CDOT asked Muller to break the project into separate design packages to match anticipated funding streams for construction. Phase 1 ($12 million) included the landslide stabilization. Phase 2 ($13 million) included the coupled shear piles. Phase 3 ($21 million) was completed in Blue Creek Canyon and Phase 4 ($8 million) was done in the Windy Point Cut Segment.

This nine-mile segment was one of the last segments of this major Colorado east-west corridor to be upgraded to current rural roadway standards.

In addition, Muller completed two other sections of US 50 widening (2.5-mile and 3-mile segments) for CDOT Region 3 in Montrose County east and west of Cimarron, Colorado ($3.4 million and $3.5 million respectively) under an IDIQ contract with CDOT Region 3.