Ill 177 over Silver Creek
FairSt. Clair County, Illinois · Wcl Mascoutah · Structure no. 082006300000000
- Built
- 1961
- 64 years old
- Condition
- Fair
- inspected July 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 268 ft
- 6 main spans
- Daily traffic
- 7,000
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Ill 177 over Silver Creek is a steel continuous stringer/multi-beam or girder carrying Ill 177 over Silver Creek in St. Clair County, Illinois. It was built in 1961, so it is 64 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 7,000 vehicles a day, roughly 5% of them trucks, projected to reach 5,858 by 2046. The structure is 268 ft (81.7 m) long and 35 ft wide. If it were closed, the detour would be 9.9 mi (16 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Ill 177 over Silver Creek built?
It was built in 1961, making it 64 years old in 2025.
What condition is Ill 177 over Silver Creek 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 Silver Creek carry?
About 7,000 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is Ill 177 over Silver Creek?
The structure is 268 ft (81.7 m) long with a longest span of 51 ft (15.5 m) and a deck 35 ft wide.
Who owns Ill 177 over Silver Creek?
It is owned by the State Highway Agency.