Bridge conditions in Humboldt County, Iowa
87 inventoried bridges · 7 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
7 of the 87 bridges the federal inventory lists in Humboldt County are rated poor; the rest split 34 good and 46 fair.
- 7 of the 87 bridges in Humboldt County, Iowa, are rated in poor condition (8.0%) in the 2025 National Bridge Inventory, as of .
- 34 bridges (39.1%) are rated good and 46 (52.9%) fair.
- The median Humboldt County bridge was built in 1970.
- The busiest poor-rated bridge is Local over Dm River (built 1911), carrying about 60 vehicles a day.
Good 39.1% · Fair 52.9% · Poor 8.0% of 87 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Local over Dm River | 1911 | 60 | Poor |
| 215TH St over Des Moines River | 1899 | 50 | Poor |
| FM over Dm River | 1905 | 30 | Poor |
| Local over Drainage Ditch | 1948 | 15 | Poor |
| Local over Prairie Creek | 1900 | 15 | Poor |
| Local over Dm River | 1924 | 11 | Poor |
| Local over Dd | 1900 | 11 | Poor |
Busiest bridges in the 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 |
| US 169 over Trulner Creek | 1995 | 3,220 | Fair |
| US 169 over Lotts Creek | 1985 | 3,220 | Fair |
| US 169 over Branch Lotts Creek | 1985 | 3,220 | Fair |
| US 169 over Branch Lotts Creek | 1985 | 3,220 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Iowa: Iowa bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.