Illinois Route 40

Bob Michel Bridge carrying Illinois Route 40 over the Illinois River.

Illinois 40 is known as Knoxville Avenue in the Peoria area, generally south of Illinois Route 6. Route 40 crosses over Interstate 74 north of downtown, and then grows complex in the downtown area, as there are three turns in a one-block length. Illinois 40 then emerges onto William Kumpf Boulevard and crosses over the Illinois River using the Bob Michel Bridge. On the other side of the river, Illinois 40 is briefly called Washington Street. It then is routed onto an onramp to Interstate 74, where there is an exit to Camp Street before terminating at I-74.

Originally, SBI Route 40 ran from Sterling to Stockton.[3] In 1935, IL 40 got cut back to Mount Carroll in favor of IL 78.[4] By 1938, Illinois Route 88 entirely acquired IL 40 north of Sterling.[5] In 1987, Illinois Route 5, a four-lane freeway which crosses Illinois 40, was designated Interstate 88 east of I-80.[6] As of 1995, IDOT redesignated Illinois 88 as Illinois 40 to prevent confusion.[7] Although the new number is also the number of a Federal Highway that passes through Illinois (U.S. Route 40), a great enough distance exists between them that the possibility of confusing one for the other is negligible.

IL 40 in Peoria County, north of IL 90

Prior to 2003, the Illinois 40 exit on I-74 southeast of Peoria was called "Industrial Spur". As part of the Upgrade 74 Project, the exit was renamed by the Illinois Department of Transportation to Riverfront Drive.