WIS 23 (US 151 to County P) Study

Porject limits map Wis 23

Note: Construction began May 13, 2019. This website details design and environmental information. For construction information, please see the WIS 23 Project construction webpage on the 511 Wisconsin website.


The Wisconsin Department of Transportation (WisDOT) is proposing improvements to a 19-mile stretch of WIS 23 from US 151​ to County P in Fond du Lac and Sheboygan counties. In this area, WIS 23 is a critical east-west connector between two Interstate highways, I-41 in Fond du Lac and I-43 in Sheboygan, serving freight and local, regional, and statewide traffic. The majority of WIS 23 from US 151 to County P is a rural, 2-lane highway, with safety, access, and operational concerns. Improvements are being considered to address these concerns.

What’s new?

WisDOT, with the Federal Highway Administration (FHWA), completed an updated Limited Scope Supplemental Environmental Impact Statement (LS SEIS) for this project. An LS SEIS reviews certain aspects of an existing environmental impact statement. See 23 CFR s. 771.130(f). During recent litigation, a federal court raised concerns with how WisDOT discussed its traffic forecasting methodology in its 2014 environmental document, and with how WisDOT accounted for updated municipal- and county-level population projections. WisDOT used the LS SEIS document process to address the court’s concerns, as well as to update prior analyses, as needed, since the study’s prior Record of Decision (ROD) was issued in March 2014.


The following dates show key process milestones. WisDOT will update this information when further details become available.