Planning Is Paramount: Transportation Project Delivers Milestone Early

 |  Civil & Transportation


Just before the holidays, Sundt and their JV partner Cannon Builders achieved a major milestone on the I-15/I-86 System Interchange project in Pocatello, Idaho. Amid challenges such as poor quality soil and below freezing temperatures, the project team completed the new I-15 northbound roadway alignment over a week early. This traffic switch opened up additional areas for construction on the future I-15 southbound roadway portion of the project.



Weathering Obstacles

Known as the “Flying Y,” the ITD I-86 and I-15 System Interchange was built in the mid-1960s. With increased traffic causing congestion, the Idaho Transportation Department (ITD) is upgrading the interchange to improve operations, safety and mobility. Sundt-Cannon began the reconstruction project in 2022.

“The main obstacles the team had to overcome leading up to the traffic switch was the poor quality of the existing soil materials and impending winter weather. We knew these conditions would hinder several critical activities needed for the traffic switch,” explained Thiago Bezerra, Senior Project Manager.

The soil in question resembles what Thiago calls “moon dust.” The soil needed to be thickened, but, add too much water, and it becomes like quicksand—unworkable. “Finding the sweet spot to where the existing soil can be compacted to specifications was a dance our field superintendents had to stay on top of daily.”

The other challenge—fast approaching winter weather—required meticulous planning. Through strategic and creative approaches, the team developed a work sequencing plan that overcame these risks. The plan was reviewed and updated daily, with some activities including an hour-by-hour schedule.

“Such planning and execution proved to be paramount: the very next day after the traffic switch, temperatures plummeted, and we were hit with a massive snowstorm,” Thiago said. This attention to detail and successful planning ultimately allowed the traffic switch to take place over a week ahead of schedule.



The Road Ahead

During the most recent phase, the team completed construction on three bridges out of eight total planned reconstructions. After the successful traffic switch, two of the original bridges on the existing I-15 southbound were demolished, making way for the construction of new bridges. A total of five bridges will be constructed in upcoming phases.

The completion of these bridges and several other activities brings the project near its halfway point. After the traffic switch, the team is now in a position to tackle plenty more work. Although the team will be faced with severe winter weather conditions, they are fully geared up to tackle this next phase and push the project across the finish line.

“I want to take this opportunity to recognize our team for making this happen. They work long hours, sometimes on weekends and nights, in adverse weather to keep the project on track. Without our craft employee-owners, none of this would happen.” – Thiago Bezerra, Senior Project Manager.

In the upcoming project phases, the team will build the new I-15 southbound alignment, along with four new ramps to connect all movements between I-15 and I-86. They will also construct eight mechanically stabilized earth (MSE) walls, most of which will support the remining new bridges built in future phases. Another major portion of the project the team plans to start is Chubbuck Road and its associated pedestrian and bike trail, which will connect the east and west side of town, currently divided by I-15.

Check out the work Sundt is performing in the intermountain region.