This WisDOT project will replace the pavement and make various improvement along the I-43 Rock Freeway between WIS 83 and WIS 164 in Waukesha County. As part of this project, the I-43 and WIS 164 interchange will also be reconstructed into a new Diverging Diamond Interchange (DDI) layout.

Learn more about the Diverging Diamond Interchange here

Project Improvements:

In addition to replacing the pavement structure along I-43 and constructing a DDI at the I-43 and WIS 164 interchange, additional improvements include:

• Replace pavement on the southbound I-43 exit ramp to WIS 83 and northbound I-43 entrance ramp from WIS 83.
• Pavement replacement on WIS 164 between County ES and just south of Woodland Lane.
• Improvements to the Big Bend Park and Ride (southeast quadrant of WIS 164 interchange)
• Replace guardrail
• Culvert pipe repair/replacement and cleaning
• Drainage improvements at the northwest quadrant of I-43 and WIS 164
• Replace existing signing and pavement marking
• Structure repairs multiple bridges along the corridor

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Diverging Diamond Interchange:

What is a Diverging Diamond Interchange (DDI)?

Traffic Impacts:

Construction will be completed in multiple stages. Traffic will be maintained in both directions of I-43. Traffic will be reduced to a single lane in each direction and crossovers will be utilized to maintain traffic.

Several long-term ramp closures in the WIS 164 and WIS 83 interchanges. Detours will be provided.

Long-term lane reductions on WIS 164 between County ES and Woodland Lane.

Occasional overnight full interstate closures are anticipated.

Access for residents, businesses, and emergency services will be coordinated and maintained throughout the project limits during construction.

Schedule:

Construction on this project is scheduled to begin in early 2026 and continue into 2028. Work will be paused during the winter months.