U.S. Route 67 (US 67) is a component of the United States Numbered Highway System that connects Presidio, Texas, to Sabula, Iowa. In Illinois, it serves the western region of the state known as Forgottonia, named for the lack of regional transportation and infrastructure projects. The highway begins its path through the state by crossing the Clark Bridge over the Mississippi River from Missouri at Alton and heads northward through Jerseyville and Jacksonville before it crosses the Illinois River at Beardstown. The northern half of the route serves Macomb and Monmouth before it enters the Quad Cities. It leaves the state at Rock Island by crossing the Rock Island Centennial Bridge over the Mississippi River into Davenport, Iowa.

Illinois Route 100 (IL-100) is a 159.09-mile-long (256.03 km) state highway in the southwest Illinois. It generally parallels the Illinois River. Starting in downtown Alton, it trends northward to Buckheart Township near Canton. It makes up much of the Illinois River Road, a U.S. National Scenic Byway.