[1] Illinois 8 largely parallels Interstate 74 from Maquon to Washington.

Illinois 8 turns east onto Camp Street with U.S. 150 eastbound.

At the Washington Street intersection, U.S. 150 leaves Illinois 8 and runs east-southeast towards Morton, while Illinois 8 runs east-northeast through unincorporated Sunnyland.

[2] It was truncated in 1965, with some of its segments moving to its modern alignment from Illinois Routes 78 and 116[citation needed] West Farmington Road from Illinois Route 116 (West Plank Road) through West Peoria to Illinois Route 8 (West Southport Road) was marked as "Spur-IL-8" until 1970.

Today, the route is marked as Farmington Road and not numbered.