US Bridges

Ill 178 over Vermilion River

Fair

LaSalle County, Illinois · 3.7 MI S of Ill 71 · Structure no. 050009600000000

Built
1934
91 years old, rebuilt 1989
Condition
Fair
inspected March 2024
Type
Other
Concrete
Length
392 ft
3 main spans
Daily traffic
1,650
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 178 over Vermilion River is a concrete other carrying Ill 178 over Vermilion River in LaSalle County, Illinois. It was built in 1934 and reconstructed in 1989, so it is 91 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 1,650 vehicles a day, roughly 18% of them trucks, projected to reach 2,121 by 2046. The structure is 392 ft (119.5 m) long and 35 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

Open in Google Maps
CarriesIll 178
CrossesVermilion River
Location3.7 MI S of Ill 71
RouteState Highway 178
CountyLaSalle County
StateIllinois
Coordinates41.25607, -89.01211
Functional classRural Major 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionMarch 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment7: Better than present minimum criteria
Operating rating56.1 US tons
Inventory rating33.6 US tons

Structure

Structure typeOther
MaterialConcrete
DeckConcrete, cast-in-place
Main spans3 (+5 approach)
Design loadHS 20
Structure length392 ft (119.5 m)
Longest span86 ft (26.2 m)
Deck width35 ft (10.6 m)
Roadway width32 ft (9.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic1,650 (2023)
Projected traffic2,121 by 2046
Trucks18%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemNo

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusPossibly eligible for the National Register; requires further investigation
Work proposedNone recorded
Estimated improvement cost—
NavigationNo navigation control on waterway

Frequently asked questions

When was Ill 178 over Vermilion River built?

It was built in 1934, making it 91 years old in 2025. It was reconstructed in 1989.

What condition is Ill 178 over Vermilion River 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 March 2024.

How much traffic does Ill 178 over Vermilion River carry?

About 1,650 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is Ill 178 over Vermilion River?

The structure is 392 ft (119.5 m) long with a longest span of 86 ft (26.2 m) and a deck 35 ft wide.

Who owns Ill 178 over Vermilion River?

It is owned by the State Highway Agency.