WIS 145 Roundabouts

A unique system of five closely spaced roundabouts on a major corridor in the Village of Richfield was a first-of-its-kind roundabout project in Wisconsin based on the number of roundabouts and the project’s complexity. Four of these roundabouts were located at ramp terminals—two roundabouts at the US 41 interchange and two roundabouts at the US 45 interchange on WIS 145.

raSmith also incorporated spiraling central islands and pavement markings, a relatively new technique in the United States at the time of this project. The spiraling technique eliminated the need for drivers to change lanes within the circulatory roadway. Additional innovation was demonstrated in the development of a unique design vehicle used to model a business owner’s 99-foot truck/trailer’s paths through the roundabouts.

WIS 145 required upgrading due to traffic volumes that were expected to increase from 6,000 vehicles per day to 18,000 vehicles per day based on the recent construction of a Cabela’s store, outparcels, and future development.  Roundabouts, as the preferred intersection alternatives, greatly reduced construction costs by requiring only deck replacements with some widening for the WIS 145 bridges over US 41 and 45, instead of the replacement of the entire bridges.

This project won the 2011 WisDOT Excellence in Highway Engineering Award for Consultant Design and the 2011 Best of State award and National Recognition from the American Council of Engineering Companies.