 Most of the route is concurrent with Interstate 41 in the state, with the exception of the portion between Howard, a suburb of Green Bay, and Marinette.US 41 is a freeway for nearly 85 percent of its route through Wisconsin, with the exceptions being a expressway section from the US 141 interchange in Oconto County to Marinette and a surface arterial section within Marinette.The highway runs concurrently with I-94 from Milwaukee to the Illinois border and concurrently with I-41 from Howard to the Illinois border.