County profile · official public datasets

Jasper County, IA

382 public highway bridges tracked in the FHWA National Bridge Inventory: 38.5% rated Good, 32.5% Fair, 29.1% Poor.

382
Public bridges: 38.5%
Good condition: 29.1%
Poor condition

The verdict

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

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

77th
of 99 on Poor share: 29.1%
Poor-condition share: 382
public highway bridges: 1977
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.

Jasper County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Jasper County ranks #77 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 29.1%). Jasper County, Iowa contains 382 public highway bridges. Roughly 38.5% are rated “Good,” 32.5% “Fair,” and 29.1% “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

382

Public highway bridges in Jasper County

Good condition

38.5%

147 of 382 rated 7-9

Fair condition

32.5%

124 of 382 rated 5-6

Poor condition

29.1%

111 of 382 rated 4 or below

In-state Poor-share rank

#77 of 99

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

Condition distribution

Share of 382 NBI-tracked bridges by lowest applicable component rating.

Good

38.5% (147)

Fair

32.5% (124)

Poor

29.1% (111)

Jasper County's Poor-condition bridges carry 16,570 vehicle crossings a day

That is 2.3% of the county's reported daily bridge traffic on 28.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 151 crossings a day against 968 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 381 of 382 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

45.8% of Jasper County's bridges have passed the 50-year mark

175 of the 382 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 38.5% 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 9.2% of the county's Poor-condition bridge traffic

HIGHWAY F-48 W over SMALL STREAM, built 1949, carries 1,530 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 111-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 16,570 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

12
1920s

26
1930s

22
1940s

19
1950s

27
1960s

50
1970s

39
1980s

28
1990s

45
2000s

37
2010s

57
2020s

20

What this shows Construction peaked in the 2010s, when 57 of the county's bridges still in the inventory were built, which is 14.9% of those with a recorded year. That cohort is now 5 to 14 years old in the 2024 inventory. Its average build year (1977) matches the Iowa average (1979).

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

The 5 Iowa counties nearest Jasper County in number of bridges, with their condition splits. Its 29.1% Poor share is the 6th-lowest of these 6. Its average build year of 1977 against a peer-group mean of 1982 is 5 years older.

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

Bridge inventory size and condition shares for Jasper County and the 5 Iowa counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Jasper County (this page)	382	38.5%	32.5%	29.1%	1977
Benton County	374	34.2%	42.8%	23%	1984
Clinton County	372	66.7%	30.4%	3%	1986
Johnson County	372	39.5%	50.3%	10.2%	1979
Fayette County	362	35.1%	40.3%	24.6%	1974
Dubuque County	346	50.6%	40.8%	8.7%	1989

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

Similar inventory size

Nearest county inventories outside IA (382 bridges here).

Orleans County, LA · 382 bridges
Stephens County, OK · 382 bridges
Trumbull County, OH · 383 bridges
Webb County, TX · 383 bridges

Similar average build year

Nearest mean year-built outside IA (1977 here).

San Diego County, CA · avg 1977 · 1,632 bridges
King County, WA · avg 1977 · 1,238 bridges
Riverside County, CA · avg 1977 · 1,117 bridges
Shelby County, TN · avg 1977 · 1,077 bridges

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

All 382 Good 147 Fair 124 Poor 111

Good-condition bridges (147)

Sort:

Jasper County Bridge Snapshot

Condition distribution

Jasper County's Poor-condition bridges carry 16,570 vehicle crossings a day

45.8% of Jasper County's bridges have passed the 50-year mark

One structure carries 9.2% of the county's Poor-condition bridge traffic

How Jasper 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 (147)

E 132ND ST S

S 88TH AVE E

E 122ND ST S

W 4TH ST S

S 112TH AVE W

W 4TH ST S

N 4TH AVE W

N 115TH AVE W

W 124TH ST N

PINION AVE

S 120TH AVE E

F48

MONARCH AVE

T38

INDIGO AVE

S 12TH AVE WEST

S 124TH AVE E

RODEO AVE E

W 132ND ST S

E 60TH ST S

IA 117

IA 117

FM

U.S. 6

F48

FOREST ST S

S 112TH AVE EAST

LOCAL

IA 117

F 17

W 93RD ST S

IA 14

US 6

F24

S 104TH AVE W

S 96TH AVE W

LOCAL

IA 14

N 99TH AVE E

T 12

LOCAL

IA 14

S 60TH AVE W

IOWA SPEEDWAY DR

S 12TH AVE E

E 110TH ST S

E 84TH ST S

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