Colorado DOT Reports Demolition, Paving Progress on I-25 Diverging Diamond Interchange

One year’s worth of work has been completed on Colorado’s Interstate 25 / U.S. Highway 50B diverging diamond interchange, including key bridge demolition and construction and concrete paving.

The Colorado Department of Transportation awarded SEMA Construction the $114 million contract to build a diverging diamond interchange in the City of Pueblo, and work began in December 2024. The finished project will consist of five new bridges, new retaining and noise walls, road and ramp reconstruction, new embankments, and improved safety, drainage and erosion control.

In 2025, the following work was completed on the interchange, according to CDOT:

• Three of the interchange’s five bridges progressed notably last year. Crews have set 46 girders and installed 91 structural caissons totaling 3,140 linear feet.
• The bridge over US 50B and the southbound I-25 on- and off-ramps have been demolished ahead of schedule, saving roughly 3,000 hours and opening work areas at a faster rate.
• SEMA crews have also placed 14,000 square yards of concrete – using 450 truckloads – and partially completed paving the new northbound I-25 collector-distributor road between US 50B and 29^th Street.
• About 650,000 cubic yards of soil have been moved to elevate the roadway and support bridge construction.

Work on the diverging diamond interchange is set to finish in early Summer 2027 and will improve drivability and safety, according to CDOT.

CDOT's plans for the project in 2026 include the following:

• Traffic shifts in February and March to work on the new mainline I-25 alignment.
• Begin finishing the western half of the new US 50B over I-25 structure in spring.
• Continued work on the new 29th Street on- and off-ramps, the I-25 collector-distributor roads and the northbound I-25 bypass road.
• Begin construction on the sound wall beside southbound I-25 between 29th Street and US 50B early this year.
• Realigning Chinook Lane by late spring or early summer.
• Begin two efforts to move traffic to the new alignment this year. Westbound US 50B traffic will move to the new alignment just north of the old US 50B interchange as early as July 2026, and eastbound US 50B traffic will move to the new alignment toward the end of 2026 or the beginning of 2027.