US Bridges

Ill 177 over Rayhills Slough

Fair

St. Clair County, Illinois · 3.1 M E JCT Ill 4 · Structure no. 082006600000000

Built
1920
105 years old, rebuilt 1953
Condition
Fair
inspected July 2024
Type
Slab
Concrete Continuous
Length
53 ft
2 main spans
Daily traffic
2,000
2023 count
Owner
State
State Highway Agency

About this bridge

Ill 177 over Rayhills Slough is a concrete continuous slab carrying Ill 177 over Rayhills Slough in St. Clair County, Illinois. It was built in 1920 and reconstructed in 1953, so it is 105 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 5 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 2,000 vehicles a day, roughly 12% of them trucks, projected to reach 1,768 by 2046. The structure is 53 ft (16.2 m) long and 34 ft wide. If it were closed, the detour would be 65.9 mi (106 km).

Location

Open in Google Maps
CarriesIll 177
CrossesRayhills Slough
Location3.1 M E JCT Ill 4
RouteState Highway 177
CountySt. Clair County
StateIllinois
Coordinates38.48068, -89.73697
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
Deck5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Superstructure5 FairAll primary structural elements are sound but may have minor section loss, cracking, spalling or scour.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Channel and channel protection7 GoodSome minor problems.
Last inspectionJuly 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation5: Somewhat better than minimum adequacy to tolerate being left in place as is
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating57.9 US tons
Inventory rating34.6 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20
Structure length53 ft (16.2 m)
Longest span25 ft (7.6 m)
Deck width34 ft (10.5 m)
Roadway width28 ft (8.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,000 (2023)
Projected traffic1,768 by 2046
Trucks12%
Lanes on structure2
Traffic directionTwo-way traffic
CarriesHighway
CrossesWaterway
Detour if closed65.9 mi (106 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 177 over Rayhills Slough built?

It was built in 1920, making it 105 years old in 2025. It was reconstructed in 1953.

What condition is Ill 177 over Rayhills Slough 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 July 2024.

How much traffic does Ill 177 over Rayhills Slough carry?

About 2,000 vehicles per day (2023 count), of which roughly 12% are trucks.

How long is Ill 177 over Rayhills Slough?

The structure is 53 ft (16.2 m) long with a longest span of 25 ft (7.6 m) and a deck 34 ft wide.

Who owns Ill 177 over Rayhills Slough?

It is owned by the State Highway Agency.