Ill 84 over Plum River
Carroll County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ill 84 over Plum River in Carroll County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1978 and reconstructed in 2024, making it 47 years old at the 2025 inventory.
- It carries about 4,200 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 96 of the 180 inventoried bridges in Carroll County rated fair (53.3%); 26 (14.4%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated October 2023, on a 24-month routine inspection cycle.
- 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 → (42.07528, -90.12523)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous steel stringer or multi-beam girder |
| Length | about 355 ft |
| Location | 1.0 Mi S Jct Ill 64 |
| NBI structure number | 008002800000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | October 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Carroll County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Il 84 over BNSF RR | 1988 | 5,550 | Fair |
| Il 84 over Soo Line Rr/city St | 1988 | 5,550 | Fair |
| US 52 & Il 64 over Straddle Creek | 1996 | 3,500 | Good |
| US 52 & Il 64 over Plum River | 1999 | 3,450 | Fair |
| Ill 73 over Straddle Creek | 1989 | 3,350 | Fair |
| Il 40 over Elkhorn Creek Trib. | 1993 | 3,250 | Good |
All bridges nearby: Carroll County, IL bridge conditions · every bridge in Carroll County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.