| State: | IL |
| Type: | IL |
| Maint: | IDOT |
| Route: | 178 |
| Alternate Name: | East 8th Road |
| Map Custom: | yes |
| Map Notes: | IL 178 highlighted in red |
| Length Mi: | 8.49 |
| Length Round: | 2 |
| Length Ref: | [1] |
| Direction B: | North |
| Direction A: | South |
| Terminus A: | in Lowell |
| Terminus B: | in North Utica |
| Junction: | in North Utica |
| Counties: | LaSalle |
| Established: | 1924[2] |
| Previous Route: | 177 |
| Previous Type: | IL |
| Next Route: | 179 |
| Next Type: | IL |
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 north of North Utica, which is better known as simply Utica. This is a distance of 8.49miles.
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 1miles south of Illinois Route 71 is the entrance to Matthiesen State Park. The route terminates at rural intersection in Lowell.
SBI Route 178 ran along the existing Illinois 178, and southwest from Lowell to what was then U.S. Route 51 in Tonica. This was dropped in the 1950s.[2]
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.[3]
The Illinois River bridge is currently under construction and is expected to be completed by late 2018. The existing cantilever bridge will be removed and replaced by a new highway bridge with decorative lighting and an added pedestrian and bicycle multi-use path.[4]