US Bridges

Ill 178 over Clark Run

Fair

LaSalle County, Illinois · 1.11 MI S of US 6 · Structure no. 050017900000000

Built
1976
49 years old
Condition
Fair
inspected December 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
35 ft
1 main span
Daily traffic
4,150
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 178 over Clark Run is a prestressed concrete stringer/multi-beam or girder carrying Ill 178 over Clark Run in LaSalle County, Illinois. It was built in 1976, so it is 49 years old, older than the Illinois average of 45.3 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 4,150 vehicles a day, roughly 17% of them trucks, projected to reach 5,252 by 2046. The structure is 35 ft (10.7 m) long and 42 ft wide. If it were closed, the detour would be 1.9 mi (3 km).

Location

Open in Google Maps
CarriesIll 178
CrossesClark Run
Location1.11 MI S of US 6
RouteState Highway 178
CountyLaSalle County
StateIllinois
Coordinates41.34525, -89.01163
Functional classUrban Collector

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection7 GoodSome minor problems.
Last inspectionDecember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation7: Better than present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating69.7 US tons
Inventory rating43.2 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans1
Design loadHS 20
Structure length35 ft (10.7 m)
Longest span34 ft (10.3 m)
Deck width42 ft (12.8 m)
Roadway width30 ft (9.1 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic4,150 (2023)
Projected traffic5,252 by 2046
Trucks17%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed1.9 mi (3 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ill 178 over Clark Run built?

It was built in 1976, making it 49 years old in 2025.

What condition is Ill 178 over Clark Run in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in December 2024.

How much traffic does Ill 178 over Clark Run carry?

About 4,150 vehicles per day (2023 count), of which roughly 17% are trucks.

How long is Ill 178 over Clark Run?

The structure is 35 ft (10.7 m) long with a longest span of 34 ft (10.3 m) and a deck 42 ft wide.

Who owns Ill 178 over Clark Run?

It is owned by the State Highway Agency.