US 550–US 160 Connection South Project

About the Project

The Colorado Department of Transportation began construction of the US 550—US 160 Connection South in late summer 2020—the final phase of the project to complete the region’s first full interchange. CDOT will construct this project using the design-build process, partnering with a contracted team led by Lawrence Construction Company. 

The overall project scope involves constructing a new, 1.1 mile, four-lane section of US 550 north of La Plata County Road 220 to connect the major highway with the existing US 160 interchange, and widening a 3.3-mile section of US 550 south of CR 220 to four lanes, tying into the CR 302 intersection. 

Project Facts

  • Budget: $98.6 million
  • Contractor: Lawrence Construction Co. and RS&H, Inc.
  • Timeline: Summer 2020 to Fall 2023
  • Location: US 550 & US 160 Interchange south of Durango, near Grandview and Three Springs

Current Construction Activities - Summer/Fall 2022

  • Earthwork, excavation of material north of CR 220
  • Roadway subgrade for new northbound alignment underway north of CR 302 to US 160 interchange
  • Continuing phased paving of new northbound alignment between CR 302 to just south of CR 220
  • Traffic switch onto new northbound alignment south of CR 220 in early fall 2022
  • Continue construction of the large and small mammal crossings
  • Complete stormwater pipes

Please refer to Key Construction Steps, (left), for more detailed information.

Project Work Zone


The Design-Build Process

The design-build process is a two-step project delivery method where the design and build phases are combined into one contract. It represents a risk-sharing approach that assigns the inherent risks to the party that is best suited to mitigate, transfer or absorb those risks that are a part of any construction project. Design-build encourages innovation and efficiency to leverage the risks and add value to the contract.

Project Benefits

By realigning US 550 to connect with the US 160 interchange in Grandview, the project will greatly enhance safety for passenger and commercial vehicles, as well as cyclists. The new connection will eliminate the steep, curved grade of the current US 550. This realignment will greatly improve safety by creating a full-service, continuous-flow interchange that eliminates signalization and at-grade intersections (including that at the base of Farmington Hill) where crashes can occur. Safety will also be improved through the widening of US 550 to four lanes, with widened shoulders and auxiliary lanes for safer merges onto and off of the highway. Finally, the project will increase safety through wildlife underpass crossings and deer fencing, which will reduce animal-vehicle collisions.

Construction Impacts

  • From 6:30 a.m. to 6 p.m., Monday through Saturday (most weeks), motorists may encounter brief, intermittent stops near CR 220 and/or on the eastbound US 160 off-ramp just east of the US 550 junction for trucks entering/exiting work areas.
  • For weekly updates on specific traveler impacts, please see and choose the Interactive Map.