Key Construction Steps

The US 550—US 160 construction phase will involve the following key 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. 

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 below)
• 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