SEMA Construction is upgrading the I-25/U.S. 50B interchange in Pueblo, Colo., to enhance safety and traffic flow. The $114 million project involves building new bridges, noise walls and roadways, with plans for a diverging diamond interchange to accommodate the 30,000 daily drivers. Construction is expected to last until summer 2027, supported by CDOT funding.
Colorado Department of Transportation photo
A Cat 960F wheel loader heads to the work zone.
The Colorado Department of Transportation (CDOT) is investing $114 million to upgrade the Interstate 25 and U.S. Highway 50B interchange in Pueblo to improve safety and traffic on roads built in the 1950s.
SEMA Construction began working in December 2024 and will have crews on-site until summer 2027.
The project is financed by Colorado Bridge and Tunnel Enterprise, among other sources.
The work zone covers I-25 from mile point 99.7 to 101.4 and U.S. 50B from mile point 315.9 to 316.6.
Crews are building five new bridge structures, retaining noise walls, embankments, drainage and erosion control along the impacted roadway, as well as reconstructing the roadway, ramps and other safety improvements.
The new interchange will address deteriorating roadways and bridges and non-standard road characteristics on I-25. The bridge structure over I-25 does not meet current standards. And it will improve local and regional mobility within and through the city of Pueblo, meeting existing and future travel demands.
"The new I-25/U.S. 50B interchange is a priority for CDOT because the current interchange poses safety concerns with many trucks on the interstate hitting the low clearance bridge or getting stuck on the interchange itself," said Shane Ferguson, CDOT Region 2 transportation director. "The new diverging diamond interchange [DDI] will help improve traffic flow on this important freight corridor and increase safety and mobility for all road users."
When completed, the new interchange will be just north of the existing location and operate as a DDI to increase safety and mobility for drivers. Approximately 30,000 vehicles use the interchange daily.
The lifespan of the bridges will be 80 years.
In 2000, the Federal Highway Administration (FHWA) and CDOT initiated a study of I-25 through Pueblo.
"The study process analyzed transportation conditions and identified transportation needs in the 7-mi. corridor from just south of Pueblo Boulevard to just south of the U.S. 50/CO 47 Interchange," Ferguson said. "This is the second project to be built as part of that study."
The project was designed by AtkinsRealis.
Construction activity is occurring adjacent to the roadway to minimize the impacts on I-25 and U.S. 50 traffic during the first year of construction.
SEMA Construction efforts thus far have focused on structures, earthwork and drainage, with crews using Cat excavators (317s, 352s and 328s), drill rigs; a Cat D6 dozer; Cat 950 and 960 loaders, a Cat 140M motor grader, and Cat 745 articulated trucks.
"[The challenges include] construction coordination with railroads, work near Fountain Creek, dewatering and complex phasing," said Kyler DeMinck, SEMA's business manager/project sponsor. "It is a tight work zone in some areas, but most construction is offline. The I-25 phase will be tight within the confines of working adjacent to and above I-25.
CDOT R2 Resident Engineer Scott Dalton also addressed the challenges SEMA faces.
"CDOT provided conceptual phasing plans, but it is up to the contractor to develop their own phasing and determine means and methods," he said.
Five bridges are being constructed, with work occurring on the Fountain Creek bridge and ramp and the railway bridge.
"Proper planning and communication between teams [is essential]," DeMinck said. "[We are] using precast girders and MSE walls."
There are 12 retaining walls totaling approximately 4,376 linear ft. and one noise wall totaling 2,045 linear ft. being built.
"Precast concrete panels are being used to construct the walls," said CDOT R2 Resident Engineer Scott Dalton. Heights vary depending on the location. There are approximately 69,609 sq. ft. of precast panel facing. Weight varies depending on the wall location and type of wall."
The panels are lifted into place by cranes and telelifts.
Drilling is required for the sound wall construction.
"It is supported by 36-in. drilled shafts, filled with concrete," Dalton said. "There are 39 shafts totaling approximately 2,796 linear feet in depth."
For the embankment and drainage and erosion control along the roadway, measures being installed include silt fences and erosion logs.
"The project has a significant amount of embankment between the new bridges, with approximately 600 cubic yards," Dalton said.
For this work, crews use Cat equipment, including dozers, excavators, motor graders and loaders.
On U.S. 50B, there are 0.7 mi. of reconstruction totaling approximately 2.8 lane mi., and on I-25 there are approximately 1.6 mi. of reconstruction, totaling approximately 6.4 lane mi., not counting ramp lanes or collector road miles.
"The new roadway will be constructed with concrete pavement ranging from 8 to 10.5 inches in depth depending on location," Dalton said. "There will be some asphalt at tie-in locations."
There are two ramps northbound (I-25 off to U.S. 50B/29th Street, U.S .50B on to I-25), and two ramps southbound (29th Street/U.S. 50B on to I-25, I-25 off to U.S. 50B).
Peak days have numerous SEMA and subcontractor personnel on-site.
SEMA said it cares for its equipment with routine maintenance from on-site mechanics. It buys and rents equipment from local and regional dealerships. CEG
Irwin Rapoport
A journalist who started his career at a weekly community newspaper, Irwin Rapoport has written about construction and architecture for more than 15 years, as well as a variety of other subjects, such as recycling, environmental issues, business supply chains, property development, pulp and paper, agriculture, solar power and energy, and education. Getting the story right and illustrating the hard work and professionalism that goes into completing road, bridge, and building projects is important to him. A key element of his construction articles is to provide readers with an opportunity to see how general contractors and departments of transportation complete their projects and address challenges so that lessons learned can be shared with a wider audience.
Rapoport has a BA in History and a Minor in Political Science from Concordia University. His hobbies include hiking, birding, cycling, reading, going to concerts and plays, hanging out with friends and family, and architecture. He is keen to one day write an MA thesis on military and economic planning by the Great Powers prior to the start of the First World War.
Read more from Irwin Rapoport here.
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