County profile · official public datasets

Montgomery County, IA

210 public highway bridges tracked in the FHWA National Bridge Inventory: 21% rated Good, 53.8% Fair, 25.2% Poor.

210
Public bridges: 21%
Good condition: 25.2%
Poor condition

The verdict

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

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

68th
of 99 on Poor share: 25.2%
Poor-condition share: 210
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.

Montgomery County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Montgomery County ranks #68 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 25.2%). Montgomery County, Iowa contains 210 public highway bridges. Roughly 21% are rated “Good,” 53.8% “Fair,” and 25.2% “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

210

Public highway bridges in Montgomery County

Good condition

21%

44 of 210 rated 7-9

Fair condition

53.8%

113 of 210 rated 5-6

Poor condition

25.2%

53 of 210 rated 4 or below

In-state Poor-share rank

#68 of 99

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

Condition distribution

Share of 210 NBI-tracked bridges by lowest applicable component rating.

Good

21% (44)

Fair

53.8% (113)

Poor

25.2% (53)

Montgomery County's Poor-condition bridges carry 6,789 vehicle crossings a day

That is 7.2% of the county's reported daily bridge traffic on 25.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 128 crossings a day against 419 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 210 of 210 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

63.8% of Montgomery County's bridges have passed the 50-year mark

134 of the 210 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 21% 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 17.5% of the county's Poor-condition bridge traffic

OLD US 71 over BNSF RR, built 1929, carries 1,187 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 53-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 6,789 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

2
1930s

5
1940s

12
1950s

34
1960s

51
1970s

39
1980s

17
1990s

23
2000s

11
2010s

12
2020s

2

What this shows Construction peaked in the 1960s, when 51 of the county's bridges still in the inventory were built, which is 24.3% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1973, 6 years older than the Iowa average of 1979.

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

The 5 Iowa counties nearest Montgomery County in number of bridges, with their condition splits. Its 25.2% Poor share is the 6th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1982 is 9 years older.

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

Bridge inventory size and condition shares for Montgomery County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Lee County	214	44.9%	41.6%	13.6%	1981
Floyd County	213	49.8%	35.7%	14.6%	1984
Howard County	210	41.9%	35.2%	22.9%	1984
Montgomery County (this page)	210	21%	53.8%	25.2%	1973
Shelby County	207	36.2%	54.1%	9.7%	1979
Washington County	207	39.6%	44.4%	15.9%	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 Montgomery 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 Montgomery County, both outside Iowa so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IA (210 bridges here).

Fulton County, IL · 210 bridges
Clinton County, IN · 210 bridges
Calloway County, KY · 210 bridges
Amite County, MS · 210 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 210 Good 44 Fair 113 Poor 53

All bridges (210)

Sort:

Montgomery County Bridge Snapshot

Condition distribution

Montgomery County's Poor-condition bridges carry 6,789 vehicle crossings a day

63.8% of Montgomery County's bridges have passed the 50-year mark

One structure carries 17.5% of the county's Poor-condition bridge traffic

How Montgomery 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 (210)

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