US 51 over Ohio River
Alexander County, Illinois · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 51 over Ohio River in Alexander 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 1937 and reconstructed in 1979, making it 88 years old at the 2025 inventory.
- It carries about 5,700 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 59 of the 93 inventoried bridges in Alexander County rated fair (63.4%); 8 (8.6%) 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 August 2024, on a 12-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 → (36.98883, -89.15116)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 5 | 5 | Fair condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Continuous steel through truss |
| Length | about 5,865 ft |
| Location | 1 Mi S Cairo |
| NBI structure number | 002000600000000 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | August 2024 |
| Inspection interval (item 91) | 12 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 Alexander County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Fai 57 over Mississippi River | 1978 | 15,000 | Fair |
| Fap 312-il 146 over Mississippi River | 2003 | 9,350 | Fair |
| Ill 146 over Drainage Ditch | 2011 | 8,550 | Good |
| I 57 NB over ILL3/US 51-cs 6010a-cnic | 1978 | 7,500 | Fair |
| I 57 SB over ILL3/US 51-cs 6010a-cnic | 1978 | 7,500 | Fair |
| Fai-57 NB over Tr-163b | 1968 | 6,100 | Fair |
All bridges nearby: Alexander County, IL bridge conditions · every bridge in Alexander County · Illinois bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.