About Diverging Diamond Interchanges (DDIs)

In 2024, the Idaho Transportation Department (ITD) did significant work to reconstruct Rexburg's South and Central interchanges, converting them into Diverging Diamond Interchanges. The project was a culmination of multiple years of research, discussion, and community involvement following expressed concerns about the loads of traffic at those intersections.

Into 2025 and beyond, the City of Rexburg will work with the ITD to ensure the upkeep and safety of these intersections are kept intact. While we recognize (and appreciate) the significant hurdle that our residents overcame during construction season in the summer of 2024, we are excited about the safety, ease of transportation, and access that these DDI's have brought to our community.

DDIs are fairly simple, however, if you're new to the area, we suggest reviewing how to drive a DDI with this video from ITD posted above!

ITD Project Website

2024 Diverging Diamond Interchanges (DDI) Construction Project

The Idaho Transportation Department (ITD) is making plans to reconstruct two US-20 interchanges in Rexburg in the summer of 2024. The interchanges are located at:

University Boulevard (Exit 332)
SH-33 (Exit 333)

Work began in mid-May of 2024 with the South Interchange (332). A full closure went into effect in June for approximately 30 days. The Intersection opened as single-lane access shortly after the full closure. Construction on the interchange continued throughout the season. In mid-July, work began on the Central Interchange (333) with a 30-day full closure taking place in August. There were significant challenges faced during the closure (including a sewer line break that caused a 24-hour water-use cessation across the city where residents we asked to avoid utilizing drains throughout the city). These challenges pushed the full closure into September, opening a single lane of the intersection around the middle of that month. Construction on both interchanges was wrapped up by November.

As the summer of 2025 approaches, cosmetic updates are expected to take place as well as final details, i.e. chip/slurry seal, line painting, and signage. There may be brief traffic interruptions to the interchanges during these times, but projects are not expected to be nearly as significant as last year's complete redesign.