County profile · official public datasets

Greene County, IA

168 public highway bridges tracked in the FHWA National Bridge Inventory: 35.1% rated Good, 50% Fair, 14.9% Poor.

168
Public bridges: 35.1%
Good condition: 14.9%
Poor condition

The verdict

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

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

Top 33%
lowest Poor share in state: 14.9%
Poor-condition share: 168
public highway bridges: 1973
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.

Greene County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Greene County ranks #33 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 14.9%). Greene County, Iowa contains 168 public highway bridges. Roughly 35.1% are rated “Good,” 50% “Fair,” and 14.9% “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

168

Public highway bridges in Greene County

Good condition

35.1%

59 of 168 rated 7-9

Fair condition

50%

84 of 168 rated 5-6

Poor condition

14.9%

25 of 168 rated 4 or below

In-state Poor-share rank

#33 of 99

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

Condition distribution

Share of 168 NBI-tracked bridges by lowest applicable component rating.

Good

35.1% (59)

Fair

50% (84)

Poor

14.9% (25)

Greene County's Poor-condition bridges carry 3,693 vehicle crossings a day

That is 5.2% of the county's reported daily bridge traffic on 14.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 148 crossings a day against 682 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 168 of 168 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

44% of Greene County's bridges have passed the 50-year mark

74 of the 168 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 35.1% 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 42.6% of the county's Poor-condition bridge traffic

S GRIMMELL RD over RACCOON RIVER, built 1947, carries 1,572 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 25-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,693 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

4
1920s

7
1930s

8
1940s

8
1950s

24
1960s

11
1970s

30
1980s

29
1990s

17
2000s

18
2010s

9
2020s

1

What this shows Construction peaked in the 1970s, when 30 of the county's bridges still in the inventory were built, which is 17.9% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1973, 6 years older than the Iowa average of 1979.

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

The 5 Iowa counties nearest Greene County in number of bridges, with their condition splits. Its 14.9% Poor share is the 2nd-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1978 is 5 years older.

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

Bridge inventory size and condition shares for Greene County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Union County	169	30.2%	37.3%	32.5%	1978
Clarke County	168	27.4%	41.1%	31.5%	1977
Greene County (this page)	168	35.1%	50%	14.9%	1973
Mitchell County	167	47.3%	42.5%	10.2%	1980
Davis County	165	44.8%	29.7%	25.5%	1985
Hamilton County	165	39.4%	40%	20.6%	1970

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

Similar inventory size

Nearest county inventories outside IA (168 bridges here).

Wilcox County, AL · 168 bridges
Kings County, CA · 168 bridges
Carroll County, GA · 168 bridges
Clayton County, GA · 168 bridges

Similar average build year

Nearest mean year-built outside IA (1973 here).

Jefferson County, AL · avg 1973 · 1,068 bridges
Erie County, NY · avg 1973 · 906 bridges
Davidson County, TN · avg 1973 · 832 bridges
Lancaster County, PA · avg 1973 · 801 bridges

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

All 168 Good 59 Fair 84 Poor 25

All bridges (168)

Sort:

Greene County Bridge Snapshot

Condition distribution

Greene County's Poor-condition bridges carry 3,693 vehicle crossings a day

44% of Greene County's bridges have passed the 50-year mark

One structure carries 42.6% of the county's Poor-condition bridge traffic

How Greene 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

All bridges (168)

R AVE / P30

L AVE / P18

J AVE / P14

330 TH / E63

270 TH

205 TH/IMPERIAL

A AVE / N58

110 TH

130 TH

150 TH

KIRKWOOD AVE

E18

QUAKER / P30

170 TH / E26

US 30

330 TH / E63

R AVE / P30

IA 4

E53 237TH ST

100 TH

S AVE

210 TH

D AVE / N65

X AVE

190 TH

235 TH / E53

310TH ST

V AVE

100 TH

IA 4

195 TH

EATON AVE / E33

V AVE

100TH ST

W AVE

120 TH

E53

337TH ST

IA 144

120 TH

160 TH / E26

L AVE / P16

ORCHARD AVE

255 TH

IA 4

US 30

IA 4 (N ELM ST)

W AVE

W AVE

190 TH

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