FM over Dm River
Humboldt County, Iowa · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- FM over Dm River in Humboldt County, Iowa, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 3 (serious condition) on the 0-9 scale.
- It was built in 1905 and reconstructed in 1982, making it 120 years old at the 2025 inventory.
- It carries about 30 vehicles a day (traffic count year 2022).
- Its listed owner is the county highway agency.
- It is one of 7 of the 87 inventoried bridges in Humboldt County rated poor (8.0%); 7 (8.0%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated November 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 → (42.77178, -94.35496)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 5 | 5 | Fair condition |
| Superstructure | 3 | 3 | Serious condition |
| Substructure | 3 | 3 | Serious condition |
Bridge details
| Structure | Steel through truss |
| Length | about 216 ft |
| Location | 092302305 |
| NBI structure number | 000000000184950 |
| Condition class | Poor |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | November 2024 |
| Inspection interval (item 91) | 12 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 Humboldt County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 169 over W Fork Des Moines River | 1997 | 7,100 | Fair |
| US 169 over Indian Creek | 2011 | 5,400 | Good |
| Ia 3 over Stream | 1939 | 4,590 | Good |
| Sumner Ave SW over West Des Moines River | 2015 | 3,472 | Good |
| US 169 over Drainage Ditch | 1985 | 3,220 | Fair |
| US 169 over Bloody Run Creek | 1985 | 3,220 | Fair |
All bridges nearby: Humboldt County, IA bridge conditions · every bridge in Humboldt County · Iowa bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.