Ill 177 over Silver CR Overflow W
PoorSt. Clair County, Illinois · 2.3MI W Il 4 · Structure no. 082006100000000
- Built
- 1961
- 64 years old
- Condition
- Poor
- inspected July 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 142 ft
- 3 main spans
- Daily traffic
- 7,000
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
Ill 177 over Silver CR Overflow W is a steel continuous stringer/multi-beam or girder carrying Ill 177 over Silver CR Overflow W 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 poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
It carries about 7,000 vehicles a day, roughly 5% of them trucks, projected to reach 5,858 by 2046. The structure is 142 ft (43.3 m) long and 36 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 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| 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 CR Overflow W built?
It was built in 1961, making it 64 years old in 2025.
What condition is Ill 177 over Silver CR Overflow W in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in July 2024.
How much traffic does Ill 177 over Silver CR Overflow W carry?
About 7,000 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is Ill 177 over Silver CR Overflow W?
The structure is 142 ft (43.3 m) long with a longest span of 51 ft (15.5 m) and a deck 36 ft wide.
Who owns Ill 177 over Silver CR Overflow W?
It is owned by the State Highway Agency.