Local over Mosquito Creek
Shelby County, Iowa · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Local over Mosquito Creek in Shelby County, Iowa, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 1 (imminent failure condition) on the 0-9 scale.
- It was built in 1930, making it 95 years old at the 2025 inventory.
- It carries about 26 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 18 of the 207 inventoried bridges in Shelby County rated poor (8.7%); 18 (8.7%) are rated poor.
- Its traffic status in the 2025 inventory is closed to all traffic (NBI item 41).
- Its class is unchanged from 2024 (poor), but component ratings moved: substructure 4 to 1.
- Status change: newly closed since 2024.
- Its most recent inspection on record is dated April 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 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 → (41.70017, -95.4727)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 4 | Poor condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 4 | 1 | Imminent failure condition |
Bridge details
| Structure | Steel through truss |
| Length | about 199 ft |
| Location | 080403505 |
| NBI structure number | 000000000306920 |
| Condition class | Poor |
| Traffic status (item 41) | Closed to all traffic |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | U: unknown foundation, not evaluated for scour |
| Fracture critical (item 92A) | Yes |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Iowa department of transportation.
Busiest bridges in Shelby County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 59 over Drainage Ditch | 1966 | 5,000 | Fair |
| US 59 over Drainage Ditch | 1970 | 4,940 | Fair |
| US 59 over West Nishnabotna River | 1970 | 4,940 | Fair |
| US 59 over Jensen Creek | 1968 | 4,680 | Fair |
| Ia 44 over West Nishnabotna River | 1978 | 3,960 | Fair |
| US 59 over Lyon Creek | 1970 | 3,240 | Fair |
All bridges nearby: Shelby County, IA bridge conditions · every bridge in Shelby County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.