County profile · official public datasets

Butler County, IA

289 public highway bridges tracked in the FHWA National Bridge Inventory: 58.1% rated Good, 26.6% Fair, 15.2% Poor.

289
Public bridges: 58.1%
Good condition: 15.2%
Poor condition

The verdict

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

Butler County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 34%
lowest Poor share in state: 15.2%
Poor-condition share: 289
public highway bridges: 1985
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.

Butler County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Butler County ranks #34 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 15.2%). Butler County, Iowa contains 289 public highway bridges. Roughly 58.1% are rated “Good,” 26.6% “Fair,” and 15.2% “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

289

Public highway bridges in Butler County

Good condition

58.1%

168 of 289 rated 7-9

Fair condition

26.6%

77 of 289 rated 5-6

Poor condition

15.2%

44 of 289 rated 4 or below

In-state Poor-share rank

#34 of 99

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

Condition distribution

Share of 289 NBI-tracked bridges by lowest applicable component rating.

Good

58.1% (168)

Fair

26.6% (77)

Poor

15.2% (44)

Butler County's Poor-condition bridges carry 10,921 vehicle crossings a day

That is 9.8% of the county's reported daily bridge traffic on 15.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 248 crossings a day against 331 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 289 of 289 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

30.8% of Butler County's bridges have passed the 50-year mark

89 of the 289 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 58.1% 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 17.4% of the county's Poor-condition bridge traffic

TRAER ST over OVRFLW SHELL ROCK RIVER, built 1900, carries 1,902 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 44-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 10,921 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

17
1910s

4
1920s

5
1930s

2
1940s

5
1950s

18
1960s

29
1970s

18
1980s

26
1990s

38
2000s

64
2010s

46
2020s

17

What this shows Construction peaked in the 2000s, when 64 of the county's bridges still in the inventory were built, which is 22.1% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1985, 6 years newer than the Iowa average of 1979.

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

The 5 Iowa counties nearest Butler County in number of bridges, with their condition splits. Its 15.2% Poor share is the 4th-lowest of these 6. Its average build year of 1985 against a peer-group mean of 1978 is 7 years newer.

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

Bridge inventory size and condition shares for Butler County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Story County	296	33.1%	53%	13.9%	1968
Cass County	295	25.4%	41%	33.6%	1976
Delaware County	293	39.2%	53.9%	6.8%	1981
Scott County	291	34.7%	55%	10.3%	1980
Grundy County	289	42.6%	32.9%	24.6%	1983
Butler County (this page)	289	58.1%	26.6%	15.2%	1985

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

Similar inventory size

Nearest county inventories outside IA (289 bridges here).

Union County, AR · 289 bridges
McKinley County, NM · 289 bridges
Knox County, IN · 290 bridges
Putnam County, IN · 290 bridges

Similar average build year

Nearest mean year-built outside IA (1985 here).

Hillsborough County, FL · avg 1985 · 840 bridges
Lancaster County, NE · avg 1985 · 661 bridges
Nueces County, TX · avg 1985 · 528 bridges
Grayson County, TX · avg 1985 · 513 bridges

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

All 289 Good 168 Fair 77 Poor 44

Good-condition bridges (168)

Sort:

Butler County Bridge Snapshot

Condition distribution

Butler County's Poor-condition bridges carry 10,921 vehicle crossings a day

30.8% of Butler County's bridges have passed the 50-year mark

One structure carries 17.4% of the county's Poor-condition bridge traffic

How Butler 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

Good-condition bridges (168)

IA 3

IA 3

SILVER AVE

LOCAL

FM

FLOYD LINE ST

FOREST AVE

IA 14

IA 188

IA 188

245TH ST

LOCAL

LOCAL

FM

LOCAL

LOCAL

LOCAL

LOCAL

255TH ST

LOCAL

LOCAL

LOCAL

230TH ST

270TH ST

160TH ST

175TH ST

180TH ST

180TH ST

WALNUT AVE

NEWELL AVE.

OAK AVE

MARSH AVE

230TH ST

FLOYD LINE ST

VAIL AVE

FLOYD LINE ST

120TH ST

MARSH AVENUE

LOCAL

LOCAL

LOCAL

GRAND AVE.

LIBERTY AVENUE

475TH ST

ARLINGTON ST

IA 57

IA 3

IA 14

T47 SINCLAIR AVE

FOREST AVE

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