Ill 15 & US 51 over Little Muddy River
Washington County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ill 15 & US 51 over Little Muddy River in Washington County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1921 and reconstructed in 1968, making it 104 years old at the 2025 inventory.
- It carries about 2,300 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 104 of the 234 inventoried bridges in Washington County rated fair (44.4%); 14 (6.0%) are rated poor.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (38.33048, -89.20523)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Concrete tee beam |
| Length | about 29 ft |
| Location | 0.6 Mi W C L Ashley |
| NBI structure number | 095000200000000 |
| Condition class | Fair |
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.