County profile · official public datasets

Guthrie County, IA

263 public highway bridges tracked in the FHWA National Bridge Inventory: 24% rated Good, 39.2% Fair, 36.9% Poor.

263
Public bridges: 24%
Good condition: 36.9%
Poor condition

The verdict

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

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

92nd
of 99 on Poor share: 36.9%
Poor-condition share: 263
public highway bridges: 1976
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.

Guthrie County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Guthrie County ranks #92 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 36.9%). Guthrie County, Iowa contains 263 public highway bridges. Roughly 24% are rated “Good,” 39.2% “Fair,” and 36.9% “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

263

Public highway bridges in Guthrie County

Good condition

24%

63 of 263 rated 7-9

Fair condition

39.2%

103 of 263 rated 5-6

Poor condition

36.9%

97 of 263 rated 4 or below

In-state Poor-share rank

#92 of 99

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

Condition distribution

Share of 263 NBI-tracked bridges by lowest applicable component rating.

Good

24% (63)

Fair

39.2% (103)

Poor

36.9% (97)

Guthrie County's Poor-condition bridges carry 6,003 vehicle crossings a day

That is 9.3% of the county's reported daily bridge traffic on 36.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 63 crossings a day against 477 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 261 of 263 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

45.6% of Guthrie County's bridges have passed the 50-year mark

120 of the 263 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 24% 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 16.6% of the county's Poor-condition bridge traffic

F 65 over MIDDLE RIVER, built 1959, carries 996 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 97-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 6,003 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

1
1920s

7
1930s

5
1940s

23
1950s

50
1960s

18
1970s

45
1980s

44
1990s

21
2000s

15
2010s

28
2020s

6

What this shows Construction peaked in the 1950s, when 50 of the county's bridges still in the inventory were built, which is 19% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year (1976) matches the Iowa average (1979).

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

The 5 Iowa counties nearest Guthrie County in number of bridges, with their condition splits. Its 36.9% Poor share is the 6th-lowest of these 6. Its average build year of 1976 against a peer-group mean of 1978 is in line with the group.

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

Bridge inventory size and condition shares for Guthrie County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Kossuth County	267	44.6%	39%	16.5%	1987
Bremer County	266	51.9%	36.1%	12%	1990
Cerro Gordo County	266	44%	51.1%	4.9%	1975
O'Brien County	264	51.9%	43.2%	4.9%	1976
Guthrie County (this page)	263	24%	39.2%	36.9%	1976
Clayton County	256	30.5%	59%	10.5%	1964

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

Similar inventory size

Nearest county inventories outside IA (263 bridges here).

Douglas County, CO · 263 bridges
Bingham County, ID · 263 bridges
Henry County, MO · 263 bridges
Sequoyah County, OK · 263 bridges

Similar average build year

Nearest mean year-built outside IA (1976 here).

Marion County, IN · avg 1976 · 958 bridges
Mohave County, AZ · avg 1976 · 641 bridges
Comanche County, OK · avg 1976 · 593 bridges
Prince George's County, MD · avg 1976 · 576 bridges

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

All 263 Good 63 Fair 103 Poor 97

Poor-condition bridges (97)

Sort:

Guthrie County Bridge Snapshot

Condition distribution

Guthrie County's Poor-condition bridges carry 6,003 vehicle crossings a day

45.6% of Guthrie County's bridges have passed the 50-year mark

One structure carries 16.6% of the county's Poor-condition bridge traffic

How Guthrie 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

Poor-condition bridges (97)

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