Illinois Route 15

bridge serving IL 14/IN 64. It had since been replaced by a new beam bridge. West of Mt. Vernon, IL 15 was part of US 460. Until the 1960s, IL 15 went on the IL 160 corridor from Addieville to Okawville, then west on the present IL 177 corridor to Belleville. The section from Nashville to St. Libory was once IL 110, but this was back in the 1940s before US 460 was signed. ==Major intersections==