Ill 177 over Trib to Kaskaskia R
Washington County, Illinois · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ill 177 over Trib to Kaskaskia R in Washington County, Illinois, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the culvert, rated 7 (good condition) on the 0-9 scale.
- It was built in 1995, making it 30 years old at the 2025 inventory.
- It carries about 1,650 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 116 of the 234 inventoried bridges in Washington County rated good (49.6%); 14 (6.0%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (good), but component ratings moved: culvert 8 to 7.
- Its most recent inspection on record is dated July 2024, on a 48-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (38.44172, -89.47071)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Culvert | 8 | 7 | Good condition |
Bridge details
| Structure | Concrete culvert |
| Length | about 25 ft |
| Location | 3.5M E of I-64 |
| NBI structure number | 095200700000000 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 48 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Washington County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Fai 64 EB over Kaskaskia River | 1971 | 15,500 | Fair |
| Fai 64 WB over Kaskaskia River | 1971 | 15,500 | Fair |
| Fai 64 EB over Kaskaskia R Overflow | 1969 | 15,500 | Good |
| Fai 64 WB over Kaskaskia R Overflow | 1969 | 15,500 | Good |
| Fai 64 WB over Plum Creek | 1969 | 15,500 | Fair |
| Fai 64 EB over Plum Creek | 1969 | 15,500 | Fair |
All bridges nearby: Washington County, IL bridge conditions · every bridge in Washington County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.