 Upon reaching Menomonee Falls, the road expands into a four-lane boulevard for just over one mile (1.6 km), straddling the Waukesha and Milwaukee County line before intersecting with US-41/45 again.At this point, the road heads into the city limits of Milwaukee and becomes a freeway, officially known as the Fond du Lac Freeway, though this term is rarely used locally.Although it was originally planned to continue into the heart of downtown, the freeway ends after just under five miles (8 km) at which point it intersects with 68th Street and Hampton Avenue.