US 41 Expansion

Winnebago County


US 41 is a critical transportation corridor that spans 200-miles of highway connecting two crucial economic regions in Wisconsin: southeastern Wisconsin and the Fox Valley. The State of Wisconsin took on the task of revamping US 41 to improve the quality of life for the people who live, work, or travel on or near this important highway. As northeast Wisconsin’s largest ever road construction project, the reconstruction of US 41 represents a significant step forward for Wisconsin and its economy, and features the latest in design and technology, including designs that reflect and complement surrounding communities and use of open space to visually link natural areas adjoining the highway corridor. Improvements include the addition of traffic lanes, the rebuilding of 16 interchanges, installation of Intelligent Transportation Systems (ITS) and construction of 40 roundabouts.

The Witzel Avenue Overpass, Washburn Street, Koeller Street and Rath Lane reconstruction were components of the 1120-11-71 US 41 expansion project in the City of Oshkosh, Wisconsin. Gremmer & Associates, Inc. led the roadway design for this project as part of a team with CH2M Hill and Ourston Roundabout Engineering.  In addition, Gremmer & Associates was responsible for the drainage and stormwater management design for the US 41 central and north segments of Winnebago County and for the survey and right-of-way plat for the US 41 central segment of Winnebago County.

Witzel Avenue Overpass, Oshkosh WisconsinWitzel Avenue Overpass, Oshkosh Wisconsin
Image courtesy of the Wisconsin Department of Transportation 

Project Description

The project consisted of reconstructing the Witzel Avenue overpass over US 41 and the reconstruction of the frontage roads on either side of the overpass. The overall project was 1.75 miles long and included 2 modern roundabout intersections, 3 bridges and 3 retaining walls. The project cost was approximately $8.25 million and construction took place in 2009 and 2010.

The project is positioned in one of Wisconsin’s major travel corridors and routes approximately 14,000 vehicles per day between the highly developed commercial corridor. US 41 runs under the Witzel Avenue overpass and carries approximately 62,000 vehicles per day.  US 41 traffic is projected to increase to 105,500 vehicles per day by 2035. The City of Oshkosh has a major economic district adjacent to US 41 as the highway passes through the City’s western sector. As a result of the highly visible and impactful project, extensive coordination with City of Oshkosh officials was imperative. As with other WisDOT projects in Oshkosh, a premium was placed on the project’s aesthetics and community sensitive design.

Design Elements

A key feature of the project are the two roundabouts that bookend the overpass. These multi-lane roundabouts were among the first constructed as part of the US 41 corridor expansion through Winnebago County. The roundabouts carry traffic that navigates between Witzel Avenue and the two major frontage roads in Oshkosh, Washburn and Koeller Streets. As a result of adjacent businesses and right-of-way constraints, the overpass structure had to incorporate both roundabouts while still accommodating the existing frontage roads with minimum realignment.

Do to the complexity of the US 41 Expansion project, Gremmer & Associates, Inc. implemented the use of AutoCAD Civil 3D software for the roadway and drainage design for this project.  AutoCAD Civil 3D provided the necessary tools to create an intelligent, model-based design.  Using the intelligent model the designers were able to evaluate multiple design alternatives “on the fly” which allowed them to assess the impacts of the changes quickly.

Gremmer & Associates, Inc. and this project were featured in Autodesk’s Civil 3D customer success stories.  The article can be viewed at Autodesk’s website or downloaded here.  In addition to the success story article, a webcast was shown to highlight some of the techniques used to design the project in AutoCAD Civil 3D.




Click the links below for more information.

4177_DOT_41_websafe_Eng.64               Roundabout Materials