The Colorado Department of Transportation will begin construction this month on realigning U.S. Highway 550 to connect with the Grandview interchange in south Durango. The project will complete the Grandview interchange by connecting the existing bridge over U.S. Highway 160, known locally as the “Bridge to Nowhere.”
CDOT will construct the project using the design-build process, partnering with a contracted team led by Lawrence Construction Co. and RS&H Inc. The interchange is scheduled for completion by spring of 2023.
The total cost of the project is $98.6 million. The cost includes the total of both CDOT project management and the contractor award.
The initial scope of the project would have constructed a new 1.1-mile, four-lane section of Highway 550 north of County Road 220 to connect the major highway with the existing Grandview interchange. By using the design-build process, the contractor was able to stretch funding, which allowed for the widening an additional 3.3-mile section of Highway 550 south of County Road 220 to four lanes, tying into the existing four-lane highway at the County Road 302 intersection.
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 project budget, extend cost savings and add value to the contract.
The realignment of Highway 550 to connect with the Grandview interchange is being done to enhance safety for passenger and commercial vehicles, as well as cyclists. The new connection will eliminate the steep, curved grade on Farmington Hill. The realignment will 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 Highway 550 to four lanes, with widened shoulders and auxiliary lanes for safer merges onto and off the highway. Finally, the project will increase safety through wildlife underpass crossings and deer fencing, which will reduce animal-vehicle collisions.
Initially, work hours will be from 6 a.m. to 7 p.m. Monday to Saturday (most weeks). Travelers may be stopped briefly, as necessary, to accommodate construction equipment, directed by flaggers through single-lane, alternating traffic.
For more information, call 880-2800, email [email protected] or visit www.codot.gov/projects/us550-us160-connectionsouth.