County profile · official public datasets

Floyd County, IA

213 public highway bridges tracked in the FHWA National Bridge Inventory: 49.8% rated Good, 35.7% Fair, 14.6% Poor.

213
Public bridges: 49.8%
Good condition: 14.6%
Poor condition

The verdict

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

Floyd 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 31%
lowest Poor share in state: 14.6%
Poor-condition share: 213
public highway bridges: 1984
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.

Floyd County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Floyd County ranks #31 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 14.6%). Floyd County, Iowa contains 213 public highway bridges. Roughly 49.8% are rated “Good,” 35.7% “Fair,” and 14.6% “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

213

Public highway bridges in Floyd County

Good condition

49.8%

106 of 213 rated 7-9

Fair condition

35.7%

76 of 213 rated 5-6

Poor condition

14.6%

31 of 213 rated 4 or below

In-state Poor-share rank

#31 of 99

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

Condition distribution

Share of 213 NBI-tracked bridges by lowest applicable component rating.

Good

49.8% (106)

Fair

35.7% (76)

Poor

14.6% (31)

Floyd County's Poor-condition bridges carry 14,166 vehicle crossings a day

That is 6.3% of the county's reported daily bridge traffic on 14.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 457 crossings a day against 1,519 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 213 of 213 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

27.2% of Floyd County's bridges have passed the 50-year mark

58 of the 213 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 49.8% 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 48.7% of the county's Poor-condition bridge traffic

GILBERT ST over SHERMANS CREEK, built 1914, carries 6,893 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 31-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 14,166 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

6
1910s

7
1920s

4
1930s

4
1940s

1
1950s

9
1960s

19
1970s

22
1980s

33
1990s

47
2000s

25
2010s

26
2020s

10

What this shows Construction peaked in the 1990s, when 47 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 25 to 34 years old in the 2024 inventory. Its average build year is 1984, 5 years newer than the Iowa average of 1979.

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

The 5 Iowa counties nearest Floyd County in number of bridges, with their condition splits. Its 14.6% Poor share is the 3rd-lowest of these 6. Its average build year of 1984 against a peer-group mean of 1978 is 6 years newer.

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

Bridge inventory size and condition shares for Floyd County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Harrison County	217	24.9%	56.2%	18.9%	1969
Marion County	217	38.7%	48.8%	12.4%	1984
Lee County	214	44.9%	41.6%	13.6%	1981
Floyd County (this page)	213	49.8%	35.7%	14.6%	1984
Howard County	210	41.9%	35.2%	22.9%	1984
Montgomery County	210	21%	53.8%	25.2%	1973

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

Similar inventory size

Nearest county inventories outside IA (213 bridges here).

Bonneville County, ID · 213 bridges
Calhoun County, MI · 213 bridges
Alcorn County, MS · 213 bridges
Calhoun County, MS · 213 bridges

Similar average build year

Nearest mean year-built outside IA (1984 here).

Hennepin County, MN · avg 1984 · 936 bridges
Duval County, FL · avg 1984 · 831 bridges
El Paso County, CO · avg 1984 · 686 bridges
Bell County, TX · avg 1984 · 660 bridges

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

All 213 Good 106 Fair 76 Poor 31

Good-condition bridges (106)

Sort:

Floyd County Bridge Snapshot

Condition distribution

Floyd County's Poor-condition bridges carry 14,166 vehicle crossings a day

27.2% of Floyd County's bridges have passed the 50-year mark

One structure carries 48.7% of the county's Poor-condition bridge traffic

How Floyd 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 (106)

110TH ST

US 18 EB

US 18 WB

US 18 EB

LOCAL

US 218 NB

US 218 SB

LOCAL

US 218

US 18 EB

US 18 WB

FM

LOCAL

US 18 WB

US 218 NB

LOCAL

LOCAL

LOCAL

FOOTHILL

LOCAL

LOCAL

LOCAL

BRADFORD ST

FM

US 18 EB

US 18 EB

US 18 WB

US 18 EB

DANCER AVE

280TH ST

S70 BALSAM AVE

LOCAL

US 18 WB

US 18 WB

220TH ST

195TH

LOCAL

B30 150TH ST

LOCAL

280TH ST

HOLLY AVE

N GRAND AVE

LOCAL

260TH ST

B23 110TH ST

LOCAL

LOCAL

B35 180TH ST

LOCAL

US 18 & 218

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