Bridge conditions in Delaware County, Iowa
294 inventoried bridges · 20 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
The federal inventory lists 294 bridges in Delaware County: 114 rated good, 160 fair, and 20 poor.
- 20 of the 294 bridges in Delaware County, Iowa, are rated in poor condition (6.8%) in the 2025 National Bridge Inventory, as of .
- 114 bridges (38.8%) are rated good and 160 (54.4%) fair.
- The median Delaware County bridge was built in 1981.
- The busiest poor-rated bridge is W Marion St over Maquoketa River (built 1980), carrying about 6,294 vehicles a day.
Good 38.8% · Fair 54.4% · Poor 6.8% of 294 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 |
|---|---|---|---|
| W Marion St over Maquoketa River | 1980 | 6,294 | Poor |
| 220 St over Br Robinson Creek | 1922 | 1,061 | Poor |
| FM 197 Ave over Small Stream | 1967 | 962 | Poor |
| FM 130 Ave over Sandhagen Creek | 1965 | 825 | Poor |
| 170TH St over Plum Creek | 1949 | 275 | Poor |
| Local Pheasant over Small Stream | 1973 | 97 | Poor |
| FM 240 St over Stream | 1930 | 79 | Poor |
| FM 170 St over Small Stream | 1955 | 79 | Poor |
| FM 280 Ave over Small Stream | 1973 | 79 | Poor |
| FM 140TH Ave over Small Stream | 1972 | 69 | Poor |
| 300TH St over Small Stream | 1930 | 59 | Poor |
| Loc 130TH Ave over Stream | 1970 | 42 | Poor |
| 170TH Ave over Sand Creek | 1953 | 39 | Poor |
| Loc 333 Ave over Stream | 1975 | 29 | Poor |
| 140TH St over Stream | 1972 | 29 | Poor |
| Local 220 Ave over Stream | 1967 | 26 | Poor |
| Loc 320 Ave over Small Stream | 1971 | 20 | Poor |
| 190TH Ave over Lindsey Creek | 1920 | 20 | Poor |
| Loc 275TH St over Stream | 1975 | 15 | Poor |
| Local 215 Ave over Small Stream | 1965 | 11 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 20 over Stream | 1963 | 9,700 | Fair |
| US 20 over Stream | 1963 | 9,000 | Good |
| US 20 over Drainage Ditch | 1963 | 9,000 | Fair |
| Ia 13 over Maquoketa River | 1991 | 7,900 | Good |
| Ia 13 over US 20 | 1970 | 6,400 | Fair |
| W Marion St over Maquoketa River | 1980 | 6,294 | Poor |
| Ia 13 over over Cc RR | 1969 | 5,900 | Fair |
| Ia 13 over Branch Maquoketa River | 1975 | 5,200 | Good |
| WB US 20 over Branch Plum Creek | 1963 | 4,850 | Fair |
| EB US 20 over Branch Plum Creek | 1981 | 4,850 | 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.