CDOT to break ground on US 550—US 160 Connection South

News Release

August 12, 2020 - Southwestern Colorado - Region’s first design-build project is the result of local, state and federal support and partnerships

The Colorado Department of Transportation will begin construction of the US 550—US 160 Connection South this month. The project will complete the US Highway 160 interchange by connecting the existing bridge over US 160 to US 550 to the south. CDOT will construct this project using the design-build process, partnering with a contracted team led by Lawrence Construction Company and RS&H, Inc. The interchange is scheduled for completion by the spring of 2023. 

“I want to congratulate our team in southwest Colorado (Region 5) on reaching a tremendous milestone,” CDOT Executive Director Shoshana Lew said. “This project reflects years of hard work and planning, and I am proud of their accomplishments and successful partnerships that made it a reality.” 

Director Lew also praised the collaboration and innovation among the partners involved with the planning and development of the project, which has garnered tremendous support from local, state and federal governments.

“The list of local agencies investing in this project is quite impressive,” Lew said. “The City of Durango, La Plata County and the Southern Ute Indian Tribe have all stepped forward to make a commitment to the project's success. Colorado’s Transportation Commission and Department of Local Affairs have also provided funding. And most significant is the successful $12.3 million federal FASTLANE grant award sought after by La Plata County.”

The total cost of the project is $98.6 million (this includes the total of both CDOT project management and the contractor award). 

“Director Lew referred to the innovations in regard to funding. The design and construction of this project will also be built with innovation as a key component,” CDOT Region 5 Transportation Director Mike McVaugh said. “The construction team (Lawrence Construction Company and RS&H, Inc.) was chosen and awarded this contract because of their ideas and innovation on minimizing impacts to the environment, residents and businesses in the area, while maximizing the project scope.”    


The initial scope of the project would have constructed 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. By using the design-build process the contractor was able to stretch funding, which allowed for the widening of an additional 3.3-mile section of US 550 south of CR 220 to four lanes, tying into the existing four-lane highway at the CR 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 work will involve the following key construction steps, which include several notable innovations designed by the contractor team to dramatically reduce construction impacts for the traveling public. With regard to the design-build process, some elements of these key steps are likely to evolve as the work progresses. 

US 550 Durango Work Zone Map

Graphic available at

The project construction team will:

  • Build a construction access road north of CR 220  

    • Enables equipment to get to/from the work sites with limited impacts the county roads and US highways or people traveling on these roadways

  • Construct a 600-foot bridge over Gulch A (see graphic)

  • Construct a 250-foot bridge over Gulch B

  • Begin excavation of what will amount to 1.2 million cubic yards of material along the new alignment, enabling construction of a roundabout connecting to the existing interchange bridge over US 160

    • Approximately 200 trucks a day will transport the material along a temporary construction access bridge to an on-site location (greatly limiting construction travel on county road and highways)

    • Approximately 900,000 cubic yards of the excavated material will be reused for road-base material

    • Due to the proposed design, the amount of material to be excavated during this project has been reduced by 1 million cubic yards (from CDOT’s conceptual design)

  • Construct a two-lane roundabout connecting to the existing interchange bridge over US 160 

  • Construct an 800-foot long, 20-foot high soil-nail retaining wall adjacent to what will be the new US 550 northbound alignment

  • Construct the new four-lane alignment between CR 220 and the existing interchange bridge over US 160

  • Construct up to 32 small mammal crossings (4-foot diameter average) under US 550 

  • Construct two large mammal crossings (32-feet wide by 14-feet tall) under what will become the new US 550 alignment south of CR 220

    • Will greatly reduce the incidence of animal-vehicle collisions, which have accounted for 56 percent of all crashes on this three-mile stretch in the past five years 

    • One of the animal underpasses, constructed one-half mile south of CR 220, will be used by construction haul trucks to access work sites along US 550, resulting in limited impacts to highway traffic

  • Construct 3.3 miles of US 550 south of CR 220, resulting in a divided four-lane highway

    • This segment will connect the new alignment north of CR 220 with the existing four-lane section at CR 302

    • Includes acceleration/deceleration lanes and a reconstructed intersection with CR 220 to increase highway safety

    • Greatly reduces travel impacts through construction phasing:  the two new northbound lanes will be constructed first, to the east of the existing US 550 alignment; then, two-way traffic will be shifted onto the new northbound lanes while construction continues on the southbound lanes

  • Construct new access roads and/or driveways—all with deer guards—into residences and businesses

  • Construct approximately 8 miles (4 miles on each side US 550) of 8-foot-tall wildlife fencing, including wildlife escape ramps (earthen ramps constructed within a cut in the fencing that allow large animals to exit the highway right of way)

  • Remove and revegetate the old US 550 alignment down Farmington Hill 

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.

Lawrence Construction is a family-owned and operated Colorado construction company with a 96-year history of building highway and infrastructure projects across the state.  Lawrence’s history working on design-build projects makes them uniquely qualified to complete the US 550-US 160 Connection South. As a local, Colorado contractor, Lawrence is fully vested in ensuring this project is built at the highest quality for generations of Durango residents and visitors.


A construction access road will be built first (on the future new highway alignment), enabling crews, equipment and haul trucks to enter and exit the work site. This access road will limit traffic impacts and interruptions for motorists on US 550 and CR 220. The access road will also allow crews to reach and begin building the first of two new highway bridge structures necessary to span over deep gulches. The site to the second bridge is expected to be pioneered in October from the north, at the high bridge which currently exists over US 160 at Grandview.    

Initially, work hours will be from 6 a.m. to 7 p.m., Monday through Saturday (most weeks). Travelers may be stopped briefly, as necessary, to accommodate construction equipment, directed by flaggers through single-lane, alternating traffic on US 550 or CR 220. 



Safe transportation infrastructure is essential for all of us, particularly for emergency first responders and freight drivers as Colorado navigates the COVID-19 pandemic. With that in mind, CDOT maintenance and construction crews  follow social distancing and other health safety measures to reduce COVID-19 exposure on the worksite. The Colorado Department of Public Health and Environment announced guidelines for construction activities. The public is urged to join the campaign for #DoingMyPartCO by practicing social distancing and wearing face masks.  As traffic returns to normal levels, motorists must drive cautiously and heed the speed limit so all of us can return home safely.   


In early 2019, CDOT announced its Whole System — Whole Safety initiative to heighten safety awareness. This initiative takes a systematic statewide approach to safety combining the benefits of CDOT’s programs that address driving behaviors, our built environment and the organization's operations. The goal is to improve the safety of Colorado’s transportation network by reducing the rate and severity of crashes and improving the safety of all transportation modes. The program has one simple mission—to get everyone home safely.


CDOT has approximately 3,000 employees located throughout Colorado, and manages more than 23,000 lane miles of highway and 3,429 bridges. CDOT also manages grant partnerships with a range of other agencies, including metropolitan planning organizations, local governments and airports. It also administers Bustang, the state-owned and operated inter-regional express service. Governor Jared Polis has charged CDOT to further build on the state’s multimodal mobility options.