Tr 77 over Prairie CR
Iroquois County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Tr 77 over Prairie CR in Iroquois 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 1970, making it 55 years old at the 2025 inventory.
- It carries about 50 vehicles a day (traffic count year 2022).
- Its listed owner is a town or township highway agency.
- It is one of 227 of the 568 inventoried bridges in Iroquois County rated fair (40.0%); 83 (14.6%) 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 → (40.87143, -87.9038)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 6 | Satisfactory condition |
| Superstructure | 6 | Satisfactory condition |
| Substructure | 8 | Very good condition |
Bridge details
| Structure | Concrete slab |
| Length | about 77 ft |
| Location | 3 Mi E. of Ashkum |
| NBI structure number | 038323700000000 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Iroquois County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-57 over Dranage Ditch | 2015 | 18,100 | Fair |
| I-57 over Dranage Ditch | 2015 | 18,100 | Fair |
| I-57 NB & SB over Prairie Creek | 2015 | 18,100 | Fair |
| Fai-57 over Stream | 1971 | 17,600 | Fair |
| I-57 SB over Langan Creek | 2013 | 9,550 | Fair |
| Fai-57 NB over Langan Creek | 2014 | 9,550 | Fair |
All bridges nearby: Iroquois County, IL bridge conditions · every bridge in Iroquois County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.