County profile · official public datasets

Scott County, IA

291 public highway bridges tracked in the FHWA National Bridge Inventory: 34.7% rated Good, 55% Fair, 10.3% Poor.

291
Public bridges: 34.7%
Good condition: 10.3%
Poor condition

The verdict

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

Scott County posts a top-quartile lowest Poor-condition share among rated counties in the state across mid-size county bridge inventory.

Top 22%
lowest Poor share in state: 10.3%
Poor-condition share: 291
public highway bridges: 1980
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.

Scott County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Scott County ranks #22 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.3%). Scott County, Iowa contains 291 public highway bridges. Roughly 34.7% are rated “Good,” 55% “Fair,” and 10.3% “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

291

Public highway bridges in Scott County

Good condition

34.7%

101 of 291 rated 7-9

Fair condition

55%

160 of 291 rated 5-6

Poor condition

10.3%

30 of 291 rated 4 or below

In-state Poor-share rank

#22 of 99

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

Condition distribution

Share of 291 NBI-tracked bridges by lowest applicable component rating.

Good

34.7% (101)

Fair

55% (160)

Poor

10.3% (30)

Scott County's Poor-condition bridges carry 80,403 vehicle crossings a day

That is 4.6% of the county's reported daily bridge traffic on 10.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,680 crossings a day against 4,957 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 291 of 291 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

44.3% of Scott County's bridges have passed the 50-year mark

129 of the 291 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 34.7% 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 33% of the county's Poor-condition bridge traffic

US 67 over MISS RVR RR & IA 461, built 1940, carries 26,500 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 80,403 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

6
1920s

5
1930s

2
1940s

4
1950s

23
1960s

54
1970s

46
1980s

45
1990s

43
2000s

19
2010s

27
2020s

17

What this shows Construction peaked in the 1960s, when 54 of the county's bridges still in the inventory were built, which is 18.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1980) matches the Iowa average (1979).

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

The 5 Iowa counties nearest Scott County in number of bridges, with their condition splits. Its 10.3% Poor share is the 2nd-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1979 is in line with the group.

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

Bridge inventory size and condition shares for Scott County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Story County	296	33.1%	53%	13.9%	1968
Cass County	295	25.4%	41%	33.6%	1976
Delaware County	293	39.2%	53.9%	6.8%	1981
Scott County (this page)	291	34.7%	55%	10.3%	1980
Butler County	289	58.1%	26.6%	15.2%	1985
Grundy County	289	42.6%	32.9%	24.6%	1983

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

Similar inventory size

Nearest county inventories outside IA (291 bridges here).

Macon County, MO · 291 bridges
Pickens County, SC · 291 bridges
Canyon County, ID · 292 bridges
Hancock County, IL · 292 bridges

Similar average build year

Nearest mean year-built outside IA (1980 here).

Tulsa County, OK · avg 1980 · 1,135 bridges
Miami-Dade County, FL · avg 1980 · 1,057 bridges
Pulaski County, AR · avg 1980 · 721 bridges
McLennan County, TX · avg 1980 · 714 bridges

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

All 291 Good 101 Fair 160 Poor 30

All bridges (291)

Sort:

Scott County Bridge Snapshot

Condition distribution

Scott County's Poor-condition bridges carry 80,403 vehicle crossings a day

44.3% of Scott County's bridges have passed the 50-year mark

One structure carries 33% of the county's Poor-condition bridge traffic

How Scott 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 (291)

LOCAL ROAD

FM Y-30

240TH AVE

WISCONSIN AVE

US 6

JERSEY RIDGE RD

56TH ST

UTICA RIDGE RD

I-80

N BUFFALO AVE

265TH AVE

IA 461

IA 461 & BIKEPATH

CANAL SHORE DR

NB US 61

MIDDLE RD

1ST AVE

I 280 EB

E. 32ND ST

35TH AVE

255TH ST

LOCAL

75TH AVE

ROCKINHAM RD

ALLERS GROVE RD

LOCAL

264TH ST.

22OTH ST

300TH ST

TELEGRAPH RD

I 280 EB

305TH ST

47TH AVE

I-280 (SB-EB)

288TH ST

305TH ST

300TH ST

I-280 (NB-WB)

IA 461

IA 130 WB

53RD AVE

EB IA 130

23RD ST

ARSENAL ISL RD

FAIRMOUNT ST

IA 461 NB

I 74 WB

10TH AVE

CO RD Y-68

LOCAL MUNI RD

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