The Colorado Department of Transportation (CDOT), in partnership with SEMA Construction, has made major progress on the new Interstate 25 and U.S. 50B interchange in just one year of construction.
Construction on the $114 million I-25 and U.S. 50B interchange project began in December 2024.
During construction, crews will build five new bridge structures; retaining and noise walls; roadway and ramp reconstruction; embankment; safety improvements; drainage; and erosion control. Once complete, the interchange will be just north of the current interchange and operate as a diverging diamond interchange to improve drivability and provide safer driving conditions for motorists. The project is scheduled for completion in early summer 2027.
Closing out the first year of construction, the project is celebrating the key milestones with significant progress anticipated in 2026.
2025 Construction Highlights
Accomplishments to date include:
Bridge construction: Crews have made significant progress on three of the five bridges under construction, including a new bridge over Fountain Creek and two new bridges over the Union Pacific Railroad. Crews have set 46 girders and installed 91 structural caissons, totaling 3,140 linear ft., which is three times as tall as the Eiffel Tower.
New pavement: Crews have placed 14,000 sq. yds. of concrete, equal to two NFL regulation football fields, to partially complete paving on the new northbound I-25 collector-distributor road between U.S. 50B and 29th Street. This work required 450 truckloads of concrete.
Bridge and ramp demolition: To advance and facilitate construction, crews demolished the existing U.S. 50B bridge over I-25, and the southbound I-25 on- and off-ramps. Crews removed 600 tons of material, which is about five times the weight of a blue whale. Completing removal of the U.S. 50B bridge and southbound ramps demolition ahead of schedule improves the efficiency of each construction phase. It opens new work areas at an accelerated rate, allowing vital project elements to be completed ahead of time without affecting traffic later.
Embankment: Crews completed major earthwork to elevate the roadway to support bridge construction, moving 650,000 cu. yds. of soil, which could fill an Olympic swimming pool 200 times.
Local economy support: Thirty Pueblo natives are employed on the project.
2026 Construction Lookahead
Anticipate impacts to traffic through the remainder of the project as Phase 1 (the offline portion) comes to completion in early 2026. The remaining phases will require numerous traffic pattern changes to complete the project.
In February/March, crews plan to shift northbound I-25 traffic to the east and southbound I-25 traffic to the west to work on the construction of the new mainline I-25 alignment.
As bridge construction progresses, work will begin in spring 2026 on the remaining portion (the western half) of the new U.S. 50B over I-25 structure, which will require temporary closures of I-25 for girder placement and bridge deck pours.
Crews will continue constructing the new 29th Street on- and off-ramps, the I-25 collector-distributor roads and the northbound I-25 bypass road.
Construction on the sound wall adjacent to southbound I-25 between 29th Street and US 50B is scheduled to begin in early 2026.
Westbound U.S. 50B traffic will move to the new alignment just north of the old US 50B interchange as early as July 2026. Eastbound U.S. 50B traffic will move to the new alignment toward the end of 2026 or the beginning of 2027.
The realignment of Chinook Lane will be completed in late spring or early summer 2026.
