Total bridges
197
Public highway bridges in Allamakee County
County profile · official public datasets
Allamakee County, IA
197 public highway bridges tracked in the FHWA National Bridge Inventory: 31.5% rated Good, 59.4% Fair, 9.1% Poor.
- 197
- Public bridges
- 31.5%
- Good condition
- 9.1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Allamakee County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- Top 16%
- lowest Poor share in state
- 9.1%
- Poor-condition share
- 197
- public highway bridges
- 1975
- avg year built
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.
Allamakee County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Allamakee County ranks #16 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 9.1%). Allamakee County, Iowa contains 197 public highway bridges. Roughly 31.5% are rated “Good,” 59.4% “Fair,” and 9.1% “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.
Good condition
31.5%
62 of 197 rated 7-9
Fair condition
59.4%
117 of 197 rated 5-6
Poor condition
9.1%
18 of 197 rated 4 or below
In-state Poor-share rank
#16 of 99
Among Iowa counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 197 NBI-tracked bridges by lowest applicable component rating.
Good 31.5% (62)
Fair 59.4% (117)
Poor 9.1% (18)
Allamakee County's Poor-condition bridges carry 4,177 vehicle crossings a day
That is 6.2% of the county's reported daily bridge traffic on 9.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 232 crossings a day against 386 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 197 of 197 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
47.7% of Allamakee County's bridges have passed the 50-year mark
94 of the 197 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 31.5% 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.
One structure carries 52.7% of the county's Poor-condition bridge traffic
IA 9 over MISSISSIPPI RIVER, built 1931, carries 2,200 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 18-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 4,177 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Allamakee County's bridges were built
197 bridges with a recorded construction year, grouped by decade
- 1900s 8
1900–1909
8 bridges
- 1910s 3
1910–1919
3 bridges
- 1920s 5
1920–1929
5 bridges
- 1930s 5
1930–1939
5 bridges
- 1940s 4
1940–1949
4 bridges
- 1950s
1950–1959
32 bridges
- 1960s
1960–1969
32 bridges
- 1970s
1970–1979
21 bridges
- 1980s
1980–1989
14 bridges
- 1990s
1990–1999
20 bridges
- 2000s
2000–2009
30 bridges
- 2010s
2010–2019
15 bridges
- 2020s 8
2020–2029
8 bridges
What this shows Construction peaked in the 1950s, when 32 of the county's bridges still in the inventory were built, which is 16.2% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1975) matches the Iowa average (1979).
How Allamakee County compares with Iowa's closest counties by inventory size
The 5 Iowa counties nearest Allamakee County in number of bridges, with their condition splits. Its 9.1% Poor share is the 2nd-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1975 is in line with the group.
Showing the 5 closest of 98 Iowa counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Dallas County | 199 | 44.7% | 46.2% | 9% | 1978 |
| Calhoun County | 197 | 24.4% | 50.3% | 25.4% | 1971 |
| Decatur County | 197 | 18.3% | 41.1% | 40.6% | 1972 |
| Allamakee County (this page) | 197 | 31.5% | 59.4% | 9.1% | 1975 |
| Page County | 196 | 24% | 43.9% | 32.1% | 1975 |
| Lucas County | 195 | 32.3% | 34.4% | 33.3% | 1977 |
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 Allamakee County's. Source: FHWA National Bridge Inventory, 2024 release.
Nationwide counties with similar inventory size or average build year
Two NBI-derived peer sets for Allamakee County, both outside Iowa so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside IA (197 bridges here).
- Crawford County, IL · 197 bridges
- Fountain County, IN · 197 bridges
- Warrick County, IN · 197 bridges
- Atchison County, KS · 197 bridges
Similar average build year
Nearest mean year-built outside IA (1975 here).
- San Bernardino County, CA · avg 1975 · 1,422 bridges
- Lane County, OR · avg 1975 · 1,010 bridges
- Fulton County, GA · avg 1975 · 775 bridges
- Westmoreland County, PA · avg 1975 · 620 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (117)
LUSTER HEIGHTS RD
FairOver: SMALL STREAM
A00320470, Allamakee, IA
Built 2000 Load: 32.7 t ADT: 40
IA 26
FairOver: INDIAN CREEK
5.7 mi. N of Jct. IA 9, Allamakee, IA
Built 1935 Load: 32.7 t ADT: 1,540
FM
FairOver: VILLAGE CREEK
099033305, Allamakee, IA
Built 1981 Load: 32.9 t ADT: 707
FM
FairOver: PAINT CREEK
097042203, Allamakee, IA
Built 1964 Load: 34.0 t ADT: 442
CLEAR CREEK WMA
FairOver: CLEAR CREEK
100052705, Allamakee, IA
Built 1900 Load: 34.5 t ADT: 15
LOCAL
FairOver: WATERLOO CREEK
100062413, Allamakee, IA
Built 1983 Load: 34.7 t ADT: 295
X52-GREATRVR RD
FairOver: DRAINAGE DITCH
098031104, Allamakee, IA
Built 2013 Load: 34.7 t ADT: 570
LOCAL
FairOver: YELLOW RIVER
096060506, Allamakee, IA
Built 1993 Load: 35.0 t ADT: 49
LOCAL
FairOver: BRANCH WATERLOO CREEK
100061306, Allamakee, IA
Built 1960 Load: 35.3 t ADT: 39
FM
FairOver: BR UPPER IOWA RIVER
099061504, Allamakee, IA
Built 1997 Load: 38.2 t ADT: 69
LOCAL RD
FairOver: PAINT CREEK
096030312, Allamakee, IA
Built 1986 Load: 41.1 t ADT: 982
LOCAL
FairOver: UPPER IOWA RIVER
099063007, Allamakee, IA
Built 1986 Load: 41.8 t ADT: 59
IA 76
FairOver: YELLOW RIVER
3.0 MI. S of Jct. SR X52, Allamakee, IA
Built 1980 Load: 48.3 t ADT: 2,370
X52
FairOver: COTA CREEK
000000000, Allamakee, IA
Built 1987 Load: 49.6 t ADT: 999
FM
FairOver: BRANCH YELLOW RIVER
096051305, Allamakee, IA
Built 1999 Load: 51.1 t ADT: 933
FM
FairOver: PAINT CREEK
T97NR5WSEC12SE, Allamakee, IA
Built 1990 Load: 57.8 t ADT: 147
LOCAL
FairOver: BR CLEAR CREEK
100052705, Allamakee, IA
Built 1978 Load: 97.2 t ADT: 15
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
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.