Fm-480th St. over Little Sioux River
Cherokee County, Iowa · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Fm-480th St. over Little Sioux River in Cherokee County, Iowa, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1965, making it 60 years old at the 2025 inventory.
- It carries about 60 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 68 of the 244 inventoried bridges in Cherokee County rated poor (27.9%); 68 (27.9%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated fair in the 2024 inventory and is now poor (substructure 6 to 3).
- Its most recent inspection on record is dated July 2023, 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 poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (42.82173, -95.51367)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 6 | 3 | Serious condition |
Bridge details
| Structure | Continuous steel girder and floorbeam |
| Length | about 346 ft |
| Location | 092400101 |
| NBI structure number | 000000000108870 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Cherokee County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 59 over Railroad Creek | 1973 | 7,200 | Fair |
| US 59 over Westcott Pk Loop | 1972 | 4,510 | Fair |
| US 59 over Little Sioux River | 1973 | 4,510 | Fair |
| W Bluff St over Railroad Creek | 1961 | 3,529 | Poor |
| Ia 3 over Fork Little Sioux River | 1979 | 3,410 | Fair |
| Ia 3 over Maple River | 1985 | 3,270 | Fair |
All bridges nearby: Cherokee County, IA bridge conditions · every bridge in Cherokee County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.