Ill 17 over Ill River
Marshall County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Ill 17 over Ill River in Marshall County, Illinois, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1939 and reconstructed in 1990, making it 86 years old at the 2025 inventory.
- It carries about 7,000 vehicles a day (traffic count year 2021).
- Its listed owner is the state highway agency.
- It is one of 71 of the 155 inventoried bridges in Marshall County rated fair (45.8%); 19 (12.3%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated poor in the 2024 inventory and is now fair (superstructure 3 to 5, substructure 4 to 5).
- Its most recent inspection on record is dated April 2024, on a 24-month routine inspection cycle.
- It has fracture-critical members (NBI item 92A): steel tension members without a redundant load path, which get their own scheduled inspections.
- 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 → (41.02634, -89.42053)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 3 | 5 | Fair condition |
| Substructure | 4 | 5 | Fair condition |
Bridge details
| Structure | Continuous steel through truss |
| Length | about 1,573 ft |
| Location | 9.55 Mi W of Ill 89 |
| NBI structure number | 062000300000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Illinois department of transportation.
Busiest bridges in Marshall County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-39/US 51 over Stream | 1991 | 16,500 | Fair |
| I-39/US 51(SB) over N Fk Sandy Creek | 1990 | 8,250 | Fair |
| I-39/US 51(NB) over N Fk Sandy Creek | 1990 | 8,250 | Fair |
| I-39/US 51(SB) over Sandy Creek | 1990 | 8,250 | Fair |
| I-39/US 51(NB) over Sandy Creek | 1990 | 8,250 | Fair |
| I-39/US 51(SB) over Tr 39 (frtg Rd West) | 1991 | 8,250 | Fair |
All bridges nearby: Marshall County, IL bridge conditions · every bridge in Marshall County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.