Illinois Route 178
|Maintained by IDOT|
|Length:||8.49 mi (13.66 km)|
|Existed:||1924 – present|
|South end:||Ed Lambert Road in Lowell|
|US 6 in North Utica|
|North end:||I-80 in North Utica|
Illinois Route 178 is a minor north–south state highway in north central Illinois. It runs north from the unincorporated area of Lowell to Interstate 80 about 3 miles (5 km) north of North Utica, which is better known as simply Utica. This is a distance of 8.49 miles (13.66 km).
Illinois 178 is a short state road that connects two of Illinois' more popular state parks to Interstate 80; Starved Rock State Park and Matthiessen State Park. Starting at Interstate 80, Illinois 178 intersects U.S. Route 6 at a rural intersection, and then descends into the Illinois River valley to the town of Utica.
South of Utica, Illinois 178 crosses the Illinois River via a cantilever bridge, where it meets a western entrance into Starved Rock State Park. About a mile (1.6 km) south of Illinois Route 71 is the entrance to Matthiesen State Park. The route terminates at rural intersection in Lowell.
Reconstruction through Utica
In accordance with the village of North Utica's United Recovery Plan, which was enacted following the 2004 tornado, a re-routing of Illinois 178 west of the current business district was constructed. This project, completed in summer of 2012, eliminated two sharp bends in the former alignment and diverts local truck traffic and through traffic away from the downtown area. 
- Carlson, Rich. Illinois Highways Page: Routes 161 thru 180. Last updated April 15, 2005. Retrieved April 16, 2006.
- Illinois Technology Transfer Center (2007). "T2 GIS Data". Retrieved 2007-11-08.