Construction for the new interchanges at exit 332 on University Boulevard by Applebee’s and exit 333 on State Highway 33 next to the airport, is expected to begin June 2024 according to Keith Davidson, Rexburg’s public works director.

Diverging diamond interchanges will replace the old interchanges.

“The diverging diamond interchanges, or DDIs, are a great option to use because they will reduce delays and utilize the existing structures at both locations,” said Mike McKee, an engineer of the project’s design team, in an informational video. “This will save time and money on the project.”

Exits 332 and 332, where the diverging diamonds will be constructed.

Exits 332 and 332, where the diverging diamonds will be constructed. Photo credit: Google Maps screenshot

Traffic signals will reduce time for left turns onto the highway entrance ramps, addressing a current traffic concern identified through public comment, by implementing a new two-phase timing plan instead of the traditional threephase timing plan.

The design team chose the two-phase timing plan to increase green light times.

Traditional diamond interchanges have 26 potential conflict points, whereas diverging diamond interchanges have 14, reducing the possibility of head-on collisions, according to Mckee.

New diverging diamond interchange plans and explanation from the Idaho Department of Transportation open house 30 March 2023.

New diverging diamond interchange plans and explanation from the Idaho Department of Transportation open house 30 March 2023. Photo credit: Idaho Department of Transportation

Idaho’s first divergent diamond interchange in Chubbuck was constructed in 2013, according to the Idaho Department of Transportation.

The divergent diamond interchanges will be built under the current overpasses.

A $2 million state grant will redo Pioneer Road, Yellowstone Highway and 12th West Street, which will serve as detour routes for the interchanges, according to Davidson.

Interchanges will be built one at a time.

Visit the online meeting to view the final design plans, learn how to drive a diverging diamond interchange and find more project details.