STH 76 is a high-speed, vital minor arterial that connects Oshkosh to Greenville and other nearby communities with an Annual Average Daily Traffic count of approximately 10,000 cars per day–10% of which are trucks associated with trucking companies along the project corridor.

The existing underlying concrete pavement of the roadway was in poor condition and reflecting cracking in the asphalt overlays was prevalent throughout. The existing 3-foot paved shoulders were too narrow to accommodate bicycles, and there were also several flat areas that resulted in poor drainage of the adjacent ditches. Development in the area had led to increased traffic on the roadway with a growing number of complaints about the difficulties of accessing STH 76 from the side roads, especially during peak-hour travel times.

WisDOT hired MSA to evaluate the existing roadway and intersections and perform traffic modeling analysis and intersection control evaluation reports in order to come up with a design that addresses the roadway deficiencies as well as safety and operational needs. After careful analysis, MSA determined that the installation of roundabout at three different critical intersections would both alleviate safety concerns and mitigate operational efficiency concerns for the side roads.

CTH JJ intersection, before and after

Drainage and pedestrian/bicyclist safety along the corridor were also huge concerns. MSA assisted with the negotiation and acquisition of over 60 adjacent parcels in order to re-grade ditches to achieve desirable drainage. The STH 76 corridor also has several adjacent wetlands, with a slough crossing beneath a portion of the roadway. MSA worked to steepen slopes and ditches to minimize impacts to adjacent wetlands, and to properly size and replace culverts throughout the entire roadway. Storm sewer and pipe underdrain were added at the roundabout intersections and French drains implemented throughout the project length, accompanied by new, widened and paved shoulders to boost pedestrian and bicycle safety.

The result is a transformational change to the roadway that optimizes safety, operational efficiency, and addresses roadway and drainage deficiencies, while still accommodating high truck traffic and safe, multi-modal use.

MSA was chosen to receive a WisDOT 2022 Excellence in Highway Design Award in the Consultant Rural Design category for this project and was formally recognized during the 13^th annual ACEC/WisDOT Improvement Conference March 9, 2022, in Wisconsin Dells.