Bridge conditions in Sioux County, Iowa
448 inventoried bridges · 14 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
Sioux County tracks close to typical: 14 of its 448 inventoried bridges (3.1%) are rated poor, against a national rate of about 7%.
- 14 of the 448 bridges in Sioux County, Iowa, are rated in poor condition (3.1%) in the 2025 National Bridge Inventory, as of .
- 281 bridges (62.7%) are rated good and 153 (34.2%) fair.
- The median Sioux County bridge was built in 1984.
- The busiest poor-rated bridge is FM over Floyd River (built 1954), carrying about 813 vehicles a day.
Good 62.7% · Fair 34.2% · Poor 3.1% of 448 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 |
|---|---|---|---|
| FM over Floyd River | 1954 | 813 | Poor |
| FM over Indian Creek | 1967 | 649 | Poor |
| B46 over No Name Creek | 1966 | 538 | Poor |
| FM over Indian Creek | 1965 | 469 | Poor |
| 14TH St over Creamery Creek | 1961 | 257 | Poor |
| Garfield St over Drainage | 1900 | 232 | Poor |
| Local over Small Stream | 1900 | 110 | Poor |
| FM over Dry Run | 1977 | 71 | Poor |
| Local over Small | 1978 | 34 | Poor |
| FM over Small Stream | 1962 | 34 | Poor |
| Local over Small | 1979 | 30 | Poor |
| FM over Creek | 1949 | 20 | Poor |
| 350TH St over Small Stream | 1938 | 11 | Poor |
| Local over Small | 1965 | 11 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 75 over W Fork Floyd River | 1989 | 7,300 | Good |
| US 75 over Stream | 1998 | 7,300 | Good |
| US 18 over Rogg Creek | 1985 | 6,700 | Good |
| Ia 60 over Stream | 1991 | 6,500 | Good |
| Ia 10 over Floyd River | 1993 | 5,300 | Fair |
| US 18 over Drainage Ditch | 1976 | 5,200 | Fair |
| US 18 over West Fork Floyd River | 1976 | 5,200 | Fair |
| US 18 over Floyd River | 1992 | 5,100 | Fair |
| Ia 10 over Orange City Slough | 1977 | 4,060 | Fair |
| Ia 10 over over UP RR | 1983 | 3,790 | Fair |
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.