County profile · official public datasets

Franklin County, IA

228 public highway bridges tracked in the FHWA National Bridge Inventory: 44.7% rated Good, 42.1% Fair, 13.2% Poor.

228
Public bridges: 44.7%
Good condition: 13.2%
Poor condition

The verdict

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

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

Top 27%
lowest Poor share in state: 13.2%
Poor-condition share: 228
public highway bridges: 1982
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.

Franklin County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Franklin County ranks #27 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 13.2%). Franklin County, Iowa contains 228 public highway bridges. Roughly 44.7% are rated “Good,” 42.1% “Fair,” and 13.2% “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

228

Public highway bridges in Franklin County

Good condition

44.7%

102 of 228 rated 7-9

Fair condition

42.1%

96 of 228 rated 5-6

Poor condition

13.2%

30 of 228 rated 4 or below

In-state Poor-share rank

#27 of 99

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

Condition distribution

Share of 228 NBI-tracked bridges by lowest applicable component rating.

Good

44.7% (102)

Fair

42.1% (96)

Poor

13.2% (30)

Franklin County's Poor-condition bridges carry 3,285 vehicle crossings a day

That is 1.4% of the county's reported daily bridge traffic on 13.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 110 crossings a day against 1,234 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 228 of 228 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

49.6% of Franklin County's bridges have passed the 50-year mark

113 of the 228 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 44.7% 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 20.9% of the county's Poor-condition bridge traffic

FM 255TH ST over BEAVERDAM CREEK, built 1969, carries 687 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 30-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,285 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1920s

2
1930s

3
1940s

1
1950s

31
1960s

30
1970s

57
1980s

32
1990s

8
2000s

10
2010s

39
2020s

14

What this shows Construction peaked in the 1970s, when 57 of the county's bridges still in the inventory were built, which is 25% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1982) matches the Iowa average (1979).

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

The 5 Iowa counties nearest Franklin County in number of bridges, with their condition splits. Its 13.2% Poor share is the 2nd-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1973 is 9 years newer.

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

Bridge inventory size and condition shares for Franklin County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Jones County	231	36.8%	58.9%	4.3%	1981
Franklin County (this page)	228	44.7%	42.1%	13.2%	1982
Madison County	225	16%	46.7%	37.3%	1968
Mahaska County	225	28.4%	39.1%	32.4%	1972
Sac County	224	35.7%	30.8%	33.5%	1973
Taylor County	220	24.5%	37.7%	37.7%	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 Franklin 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 Franklin County, both outside Iowa so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside IA (228 bridges here).

Jackson County, IL · 228 bridges
Attala County, MS · 228 bridges
Saratoga County, NY · 228 bridges
Pitt County, NC · 228 bridges

Similar average build year

Nearest mean year-built outside IA (1982 here).

Oklahoma County, OK · avg 1982 · 1,216 bridges
Jackson County, MO · avg 1982 · 930 bridges
Milwaukee County, WI · avg 1982 · 893 bridges
Champaign County, IL · avg 1982 · 727 bridges

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

All 228 Good 102 Fair 96 Poor 30

Good-condition bridges (102)

Sort:

Franklin County Bridge Snapshot

Condition distribution

Franklin County's Poor-condition bridges carry 3,285 vehicle crossings a day

49.6% of Franklin County's bridges have passed the 50-year mark

One structure carries 20.9% of the county's Poor-condition bridge traffic

How Franklin 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 (102)

FM 190TH ST

S33(JONQUILAVE)

FM JONQUIL AVE

KILLDEER AVE

160TH STREET

WRIGHT AVE

SPRUCE AVE

THRUSH AVE

230TH STREET

230TH STREET

THRUSH AVE

FM 210TH ST

FM 210TH ST

FM 210TH ST

FM RAVEN AVE

S33 JONQUIL AVE

MALLARD AVE

BALSAM AVE

FM 255TH ST

50TH ST

NETTLE AVE

I 35 NB ON RAMP

30TH ST

LARK AVE

VINE AVENUE

I 35 NB

SB I-35

FM RAVEN AVE

LARK AVE

INDIGO AVE

THRUSH AVE

US 65

WARBLER AVE

40TH ST

S55 SPRUCE AVE

FINCH AVE

I-35

8TH ST NW

S43 LINCOLN ST

160TH ST

NB I-35

FM 190TH ST

SPRUCE AVE

FM TIMBER AVE

NB I-35

SB I-35

FM TIMBER AVE

INDIGO AVE

FM WREN AVE

INDIGO AVE

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