Total bridges
185
Public highway bridges in Osceola County
County profile · official public datasets
185 public highway bridges tracked in the FHWA National Bridge Inventory: 38.4% rated Good, 53% Fair, 8.6% Poor.
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Osceola County pairs a top-quartile lowest Poor-condition share among rated counties in the state with an older average build year than the state inventory.
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
According to the Federal Highway Administration's 2024 National Bridge Inventory, Osceola County ranks #12 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 8.6%). Osceola County, Iowa contains 185 public highway bridges. Roughly 38.4% are rated “Good,” 53% “Fair,” and 8.6% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Total bridges
185
Public highway bridges in Osceola County
Good condition
38.4%
71 of 185 rated 7-9
Fair condition
53%
98 of 185 rated 5-6
Poor condition
8.6%
16 of 185 rated 4 or below
In-state Poor-share rank
#12 of 99
Among Iowa counties with 5+ bridges, lower share ranks better
Share of 185 NBI-tracked bridges by lowest applicable component rating.
That is 2.3% of the county's reported daily bridge traffic on 8.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 126 crossings a day against 754 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 185 of 185 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
116 of the 185 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 38.4% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
NORTHWEST BLVD over OTTER CREEK, built 1931, carries 797 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 16-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 2,010 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
185 bridges with a recorded construction year, grouped by decade
1900–1909
6 bridges
1920–1929
1 bridges
1930–1939
27 bridges
1940–1949
26 bridges
1950–1959
31 bridges
1960–1969
15 bridges
1970–1979
27 bridges
1980–1989
9 bridges
1990–1999
9 bridges
2000–2009
27 bridges
2010–2019
6 bridges
2020–2029
1 bridges
What this shows Construction peaked in the 1950s, when 31 of the county's bridges still in the inventory were built, which is 16.8% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year is 1965, 14 years older than the Iowa average of 1979.
The 5 Iowa counties nearest Osceola County in number of bridges, with their condition splits. Its 8.6% Poor share is the 1st-lowest of these 6. Its average build year of 1965 against a peer-group mean of 1977 is 12 years older.
Showing the 5 closest of 98 Iowa counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Adams County | 186 | 10.2% | 45.2% | 44.6% | 1967 |
| Osceola County (this page) | 185 | 38.4% | 53% | 8.6% | 1965 |
| Mills County | 184 | 29.3% | 51.6% | 19% | 1976 |
| Appanoose County | 183 | 41% | 27.9% | 31.1% | 1981 |
| Keokuk County | 183 | 34.4% | 45.9% | 19.7% | 1980 |
| Ida County | 182 | 42.9% | 40.7% | 16.5% | 1983 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Osceola County's. Source: FHWA National Bridge Inventory, 2024 release.
Two NBI-derived peer sets for Osceola County, both outside Iowa so the neighborhoods are not the same-state size table above.
Nearest county inventories outside IA (185 bridges here).
Nearest mean year-built outside IA (1965 here).
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Over: LITTLE OCHEYEDAN RIVER
099401901, Osceola, IA
Over: OCHEYEDAN RIVER
100403002, Osceola, IA
Over: STREAM
099413302, Osceola, IA
Over: LITTLE ROCK RIVER
100421901, Osceola, IA
Over: LITTLE OCHEYEDAN RIVER
099402902, Osceola, IA
Over: STREAM
100422002, Osceola, IA
Over: POLLY CREEK
0.9 mi. W Jct. Iowa 60, Osceola, IA
Over: STREAM
099390902, Osceola, IA
Over: DRY RUN
100402602, Osceola, IA
Over: OTTER CREEK
100412002, Osceola, IA
Over: OTTER CREEK
100413002, Osceola, IA
Over: STREAM
099412901, Osceola, IA
Over: OSTERMAN CREEK
3.4 mi. E of jct. US 59, Osceola, IA
Over: BR LITTLE OCHEYEDAN
at the jct. U.S. 59, Osceola, IA
Over: DRAINAGE DITCH
1.1 mi N of jct SR A46, Osceola, IA
Over: LITTLE OCHEYEDAN RIVER
099403201, Osceola, IA
Over: OCHEYEDAN RIVER
099403602, Osceola, IA
Over: STREAM
098420702, Osceola, IA
Over: DRAINAGE DITCH
1.1 mi. S of SR L36, Osceola, IA
Over: STREAM
098411001, Osceola, IA
Over: OTTER CREEK
099413002, Osceola, IA
Over: STREAM
098393401, Osceola, IA
Over: OTTER CREEK
099411808, Osceola, IA
Over: CREEK
098400502, Osceola, IA
Over: STREAM
098402702, Osceola, IA
Over: WAGNER CR
098420203, Osceola, IA
Over: RAT CREEK
098420401, Osceola, IA
Over: KAPPES CREEK
098421204, Osceola, IA
Over: DRY RUN
098421204, Osceola, IA
Over: RUSH LAKE OUTLET
099401401, Osceola, IA
Over: CREEK
099402402, Osceola, IA
Over: POLLY CREEK
099410604, Osceola, IA
Over: DRAINAGE DITCH
099412102, Osceola, IA
Over: DAWSON CREEK
099412902, Osceola, IA
Over: DRY RUN
099422701, Osceola, IA
Over: LITTLE OCHEYEDAN RIVER
098400901, Osceola, IA
Over: OCHEYEDON RIVER
099401603, Osceola, IA
Over: OCHEYEDAN RIVER
098390828, Osceola, IA
Over: OTTER CREEK
099420104, Osceola, IA
Over: DRAINAGE DITCH
2.6 mi. N of Jct SR B14, Osceola, IA
Over: OCHEYEDAN RIVER
098390801, Osceola, IA
Over: OTTER CREEK
099411901, Osceola, IA
Over: OTTER CREEK
000600150, Osceola, IA
Over: DRY RUN
099391601, Osceola, IA
Over: OTTER CREEK
098422802, Osceola, IA
Over: OCHEYEDAN RIVER
098392702, Osceola, IA
Over: STREAM
100403301, Osceola, IA
Over: STREAM
100420902, Osceola, IA
Read our methodology - how this data is sourced, computed, and verified.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.