Bridge conditions in Monona County, Iowa
160 inventoried bridges · 41 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
About one in 4 bridges in Monona County is rated in poor condition: 41 of 160 on the federal inventory, one of the higher shares in Iowa.
- 41 of the 160 bridges in Monona County, Iowa, are rated in poor condition (25.6%) in the 2025 National Bridge Inventory, as of .
- 60 bridges (37.5%) are rated good and 59 (36.9%) fair.
- The median Monona County bridge was built in 1970.
- The busiest poor-rated bridge is Ia 175 over I-29 (built 1959), carrying about 4,090 vehicles a day.
Good 37.5% · Fair 36.9% · Poor 25.6% of 160 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 |
|---|---|---|---|
| Ia 175 over I-29 | 1959 | 4,090 | Poor |
| Ia 141 & 175 over Maple River | 1967 | 3,720 | Poor |
| FM over Diversion Ditch | 1962 | 597 | Poor |
| FM over Dd | 1959 | 597 | Poor |
| FM over Famers Garretson Ditch | 1962 | 578 | Poor |
| FM over Soldier River | 1955 | 349 | Poor |
| FM over Haitz Dd | 1961 | 229 | Poor |
| FM over West Fork Dd | 1961 | 229 | Poor |
| FM over Willow Creek | 1979 | 199 | Poor |
| FM over Jordan Creek | 1958 | 159 | Poor |
| FM over Soldier Creek | 1949 | 159 | Poor |
| FM over Little Sioux River | 1925 | 159 | Poor |
| FM over Maple River | 1960 | 150 | Poor |
| FM over Little Sioux River | 1961 | 150 | Poor |
| FM over Little Sioux River | 1960 | 131 | Poor |
| Local over Stream | 1973 | 80 | Poor |
| FM over Nagel Dd | 1960 | 79 | Poor |
| FM over Stream | 1956 | 71 | Poor |
| FM over Jordan Creek | 1954 | 60 | Poor |
| Local over Stream | 1900 | 60 | Poor |
| FM over NE Norway Creek | 1949 | 50 | Poor |
| FM over Little Sioux River | 1960 | 45 | Poor |
| Local over Monona Harrison Dd | 1959 | 45 | Poor |
| FM over Sioux River | 1960 | 45 | Poor |
| Local over West Fork Dd | 1961 | 45 | Poor |
| FM over Willow Creek | 1952 | 40 | Poor |
| FM over Norway Creek | 1953 | 40 | Poor |
| FM over Soldier Creek | 1948 | 40 | Poor |
| Local over Mccandless Cleghorn Dd | 1970 | 40 | Poor |
| Local Road over Local Stream | 1962 | 29 | Poor |
| Local over Mccandless Cleghorn D D | 1997 | 29 | Poor |
| Local over Mccandless Cleghorn | 1976 | 26 | Poor |
| Local Road over Local Stream | 1964 | 26 | Poor |
| Local over Trib to Soldier River | 1990 | 20 | Poor |
| Local over Trib Maple River | 1900 | 20 | Poor |
| K53 Dogwood Ave over Mccandless Cleghorn | 1970 | 20 | Poor |
| Local over Jordan Creek | 1912 | 15 | Poor |
| Local over Willow Creek | 1978 | 11 | Poor |
| Local over Local Stream | 1900 | 11 | Poor |
| FM over Beaver Creek | 1958 | 11 | Poor |
| Local over Trib to Maple River | 1900 | 5 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| NB I-29 over Robinson Ditch | 2011 | 7,800 | Good |
| SB I-29 over Robinson Ditch | 2009 | 7,800 | Good |
| NB I-29 over Cleghorn Creek | 2012 | 7,250 | Good |
| SB I-29 over Cleghorn Creek | 2011 | 7,250 | Good |
| Ia 175 over Mccandlesscleghorn Ditch | 2023 | 5,300 | Good |
| Ia 175 over I-29 | 1959 | 4,090 | Poor |
| Ia 141 & 175 over Maple River | 1967 | 3,720 | Poor |
| Ia 175 over Drainage Ditch | 1964 | 2,160 | Fair |
| Ia 175 over Little Sioux River | 1959 | 2,160 | Fair |
| Ia 141 over Simmons Creek | 2014 | 1,920 | 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.