WisDOT is constructing a Diverging Diamond Interchange (DDI) at the I-39/90 and WIS 81 interchange in Beloit. The new DDI is anticipated to open in fall 2021.
Upon completion of this project in 2021, I-43 traffic with a destination in Beloit must exit at County X/Hart Road (Exit 2) and follow WIS 81 into Beloit. View the I-39/90 and I-43/WIS 81 interchange navigation map.
Why build a DDI at the I-39/90 and WIS 81 interchange?
WIS 81 has a significant amount of traffic making left turns onto the Interstate. During a typical day, it’s projected an average of 7,000 vehicles will merge onto I-39/90 northbound from WIS 81. Due to the high volume of left turns onto the Interstate, a standard diamond interchange design was not as efficient at reducing traffic congestion.
The following documents are in Adobe PDF format.