County profile · official public datasets

Jackson County, IA

246 public highway bridges tracked in the FHWA National Bridge Inventory: 26.4% rated Good, 56.5% Fair, 17.1% Poor.

246
Public bridges: 26.4%
Good condition: 17.1%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Jackson County posts a better-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 42%
lowest Poor share in state: 17.1%
Poor-condition share: 246
public highway bridges: 1983
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.

Jackson County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Jackson County ranks #42 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.1%). Jackson County, Iowa contains 246 public highway bridges. Roughly 26.4% are rated “Good,” 56.5% “Fair,” and 17.1% “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.

Total bridges

246

Public highway bridges in Jackson County

Good condition

26.4%

65 of 246 rated 7-9

Fair condition

56.5%

139 of 246 rated 5-6

Poor condition

17.1%

42 of 246 rated 4 or below

In-state Poor-share rank

#42 of 99

Among Iowa counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 246 NBI-tracked bridges by lowest applicable component rating.

Good

26.4% (65)

Fair

56.5% (139)

Poor

17.1% (42)

Jackson County's Poor-condition bridges carry 4,156 vehicle crossings a day

That is 2.6% of the county's reported daily bridge traffic on 17.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 99 crossings a day against 1,161 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 245 of 246 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

29.3% of Jackson County's bridges have passed the 50-year mark

72 of the 246 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 26.4% 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.

One structure carries 25.7% of the county's Poor-condition bridge traffic

FM over S COPPER CREEK, built 1974, carries 1,070 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 42-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 4,156 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

3
1920s

4
1930s

6
1940s

6
1950s

23
1960s

20
1970s

30
1980s

45
1990s

42
2000s

28
2010s

27
2020s

10

What this shows Construction peaked in the 1980s, when 45 of the county's bridges still in the inventory were built, which is 18.3% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year (1983) matches the Iowa average (1979).

How Jackson County compares with Iowa's closest counties by inventory size

The 5 Iowa counties nearest Jackson County in number of bridges, with their condition splits. Its 17.1% Poor share is the 2nd-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1976 is 7 years newer.

Showing the 5 closest of 98 Iowa counties eligible for comparison.

Bridge inventory size and condition shares for Jackson County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Carroll County	249	48.6%	44.6%	6.8%	1977
Cherokee County	248	34.3%	36.7%	29%	1968
Poweshiek County	248	25%	33.1%	41.9%	1974
Jackson County (this page)	246	26.4%	56.5%	17.1%	1983
Hardin County	241	36.1%	36.1%	27.8%	1981
Iowa County	241	37.3%	43.6%	19.1%	1980

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 Jackson 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 Jackson County, both outside Iowa so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IA (246 bridges here).

Cullman County, AL · 246 bridges
Piatt County, IL · 246 bridges
Jackson County, KS · 246 bridges
Buchanan County, MO · 246 bridges

Similar average build year

Nearest mean year-built outside IA (1983 here).

Dallas County, TX · avg 1983 · 3,230 bridges
Bexar County, TX · avg 1983 · 2,342 bridges
Sedgwick County, KS · avg 1983 · 1,333 bridges
Will County, IL · avg 1983 · 649 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 246 Good 65 Fair 139 Poor 42

Fair-condition bridges (139)

Sort:

Jackson County Bridge Snapshot

Condition distribution

Jackson County's Poor-condition bridges carry 4,156 vehicle crossings a day

29.3% of Jackson County's bridges have passed the 50-year mark

One structure carries 25.7% of the county's Poor-condition bridge traffic

How Jackson County compares with Iowa's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (139)

FM

BELLEVUECASCADE RD

LOCAL

LOCAL

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LOCAL RD

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50TH ST

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LOCAL

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IA 64

FM

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US 61 NB

UNION ST

SUMMIT ST

IA 64

FM

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FM

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FM

283RD ST

FM

FM

FM 13TH ST

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WATER STREET

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SOUTH MAIN ST

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SUMMIT ST

LOCAL

US 61 NB

IA 64

IA 64

LOCAL

US 61 SB

LOCAL

US 52

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