I-39/90 Expansion Project

Illinois state line to Madison, Dane and Rock counties

Diverging Diamond Interchange

The Wisconsin Department of Transportation is building Diverging Diamond Interchanges (DDIs) at key highway interchanges across the state. This innovative interchange, sometimes called a “double crossover diamond,” is designed to intuitively guide motorists through the pathways. These interchanges have been shown to increase capacity and safety, decrease congestion and minimize the cost of new infrastructure.

DDIs in Wisconsin

DDIs are being constructed at the following interchanges along I-39/90, between Beloit and Madison:

A DDI also opened at the WIS 441 and Oneida Street interchange in Appleton in 2018.