Muller served as prime consultant for this multi-disciplined project team to provide preliminary and final design for an 11.2-mile segment of I-25 North of Denver from CO 66 to CO 402.

Muller’s work on the $500 million project started in 2012 with development of traffic demand models for using managed lanes in the corridor from CO 7 to Fort Collins. Muller then completed the preliminary design for the entire CO 66 to CO 402 corridor segment. During the preliminary design phase, Muller’s structural engineers prepared structure selection reports for 22 bridges. To provide an interim remedy to mitigate rear-end accidents, Muller’s traffic engineers prepared an early action breakout project for four miles of interim safety improvements to be implemented prior to the ultimate improvements. This required widening the south bound lanes and bridge over Valley Road. The project’s preliminary design was completed in four months, with the climbing lane and bridge widening completed in early 2017.

Final design for the remainder of the project was completed in two segments under a CM/GC delivery process. Segment 5 was 6.1 miles long from CO 66 to CO 56 and includes 8 bridges, a parallel frontage road (some may be devolved), 1 interchange, 10 intersections, and ITS improvements (including managed lanes). Segment 6 was 5.1 miles long from CO 56 to CO 402 and included 13 bridges, a parallel frontage road, three interchanges (one diverging diamond with signalization, one with I-25 flipped from under to over), five intersections, two roundabouts, and a park and ride facility.

The I-25 North corridor has a dynamic community of stakeholders, with historic agricultural use remaining active amidst rapid growth and development. In addition to public meetings, our team worked with CDOT to find win-win opportunities and even cost-share partnerships with local agencies, developers, and the Division of Transit and Rail (DTR) to add value to the project.

Overall, the I-25 North Berthoud to Johnstown Reconstruction project has been one of Muller’s largest projects to date: requiring the support of all Muller service areas and encouraging collaboration between our clients, community, and staff. The preliminary and final design of these segments of I-25 North will benefit the connectivity of rural parts of northern Colorado for years to come.