The 1914 map above shows the Red Ball Route north of Janesville shifting to the section line, once the railroad gets out of the way, in the southwest corner of Section 23. This kink, approximately 1/8 mile, was turned into a small angle in 1928, and a much longer slope in 1976. When US 218 was four-laned, it kept the existing line.
Now, as part of changing US 218 to fully controlled access between Waverly and Janesville, a new alignment will take out the slope and whoosh right through the fill pond. The interchange (PDF) with 260th Street will take up the entire space of the once-horizontal segment, and have roundabouts at each ramp junction (ewww).
The project also closes the intersection of old 218 with present 218 on the north side of Janesville. Janesville’s mayor was unhappy with this in 2015 (Waterloo Courier), when the first plan came out, and I first mentioned the plan that May. Maple Street (old 218) will instead take a turn west onto a new paved road and then parallel the railroad up to the cross street at the interchange. Another paved frontage road will go north from 260th to 250th for homes on Eagle Avenue.
This is the second time Janesville has lost a fight with the state over the highway. Paving through town, expected in 1928, was held up for two years as the city tried to keep the original alignment of IA 40 on Main Street and Barrick Road. Instead, the “bypass” with the sweeping curves was built in 1930 and used until 1995. The truss bridge over the Cedar River in that project is still there!
This project, along with the previous completion of interchanges at C50 and C57, will eliminate all at-grade intersections on US 218 from near downtown Waterloo to the northwest corner of the Waverly bypass.