County profile · official public datasets

Washington County, IA

207 public highway bridges tracked in the FHWA National Bridge Inventory: 39.6% rated Good, 44.4% Fair, 15.9% Poor.

207
Public bridges
39.6%
Good condition
15.9%
Poor condition

The verdict

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

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

Top 35%
lowest Poor share in state
15.9%
Poor-condition share
207
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.

Washington County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Washington County ranks #35 of 99 Iowa counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 15.9%). Washington County, Iowa contains 207 public highway bridges. Roughly 39.6% are rated “Good,” 44.4% “Fair,” and 15.9% “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

207

Public highway bridges in Washington County

Good condition

39.6%

82 of 207 rated 7-9

Fair condition

44.4%

92 of 207 rated 5-6

Poor condition

15.9%

33 of 207 rated 4 or below

In-state Poor-share rank

#35 of 99

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

Condition distribution

Share of 207 NBI-tracked bridges by lowest applicable component rating.

Good
39.6% (82)
Fair
44.4% (92)
Poor
15.9% (33)

Washington County's Poor-condition bridges carry 5,753 vehicle crossings a day

That is 2% of the county's reported daily bridge traffic on 16% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 174 crossings a day against 1,900 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 206 of 207 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

39.6% of Washington County's bridges have passed the 50-year mark

82 of the 207 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 39.6% 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 28.7% of the county's Poor-condition bridge traffic

FM over WILLIAMS CREEK, built 1936, carries 1,650 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 33-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 5,753 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

When Washington County's bridges were built

207 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1990s, when 47 of the county's bridges still in the inventory were built, which is 22.7% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1980) matches the Iowa average (1979).

Source FHWA National Bridge Inventory (year built) As of 2024 NBI release

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

The 5 Iowa counties nearest Washington County in number of bridges, with their condition splits. Its 15.9% Poor share is the 3rd-lowest of these 6. Its average build year of 1980 against a peer-group mean of 1978 is in line with the group.

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

Bridge inventory size and condition shares for Washington County and the 5 Iowa counties closest to it in inventory size
County Bridges Poor
Floyd County 213 14.6%
Howard County 210 22.9%
Montgomery County 210 25.2%
Shelby County 207 9.7%
Washington County (this page) 207 15.9%
Audubon County 206 18.4%

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

Similar inventory size

Nearest county inventories outside IA (207 bridges here).

Similar average build year

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

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

All 207 Good 82 Fair 92 Poor 33

Poor-condition bridges (33)

UNDERWOOD AVE

Poor

Over: N FORK LONG CR

075061602, Washington, IA

Built 1953 Load: 0.0 t ADT: 131

LOCAL

Poor

Over: SM STREAM

074071710, Washington, IA

Built 1934 Load: 4.1 t ADT: 11

LOCAL

Poor

Over: S. FORK LONG CREEK

076083602, Washington, IA

Built 1953 Load: 6.0 t ADT: 71

LOCAL

Poor

Over: NORTH FORK LONG CREEK

076072901, Washington, IA

Built 1929 Load: 8.2 t ADT: 5

LOCAL ROAD

Poor

Over: SMALL STREAM

077060804, Washington, IA

Built 1966 Load: 9.1 t ADT: 80

FM

Poor

Over: DEER CREEK

077081001, Washington, IA

Built 1953 Load: 10.0 t ADT: 50

LOCAL

Poor

Over: DAVIS CREEK

076071502, Washington, IA

Built 1980 Load: 11.2 t ADT: 11

LOCAL

Poor

Over: WHISKEY CREEK

076063304, Washington, IA

Built 1917 Load: 14.4 t ADT: 60

FM

Poor

Over: WALNUT CREEK

074082303, Washington, IA

Built 1955 Load: 16.1 t ADT: 45

LOCAL ROAD

Poor

Over: SMALL STREAM

076090802, Washington, IA

Built 1928 Load: 16.2 t ADT: 60

B AVE

Poor

Over: SMALL STREAM

077071800, Washington, IA

Built 1936 Load: 17.0 t ADT: 938

FM

Poor

Over: N. FORK LONG CREEK

076072802, Washington, IA

Built 1925 Load: 17.2 t ADT: 160

FM

Poor

Over: SKUNK RIVER

074091004, Washington, IA

Built 1957 Load: 17.8 t ADT: 120

LOCAL

Poor

Over: SM STREAM

077090103, Washington, IA

Built 1974 Load: 18.0 t ADT: 40

FM

Poor

Over: SMALL STREAM

076082104, Washington, IA

Built 1917 Load: 19.3 t ADT: 50

LOCAL ROAD

Poor

Over: SOUTH FORK LONG CREEK

075062806, Washington, IA

Built 1914 Load: 21.0 t ADT: 11

LOCAL ROAD

Poor

Over: SMALL STREAM

075070102, Washington, IA

Built 1917 Load: 21.0 t ADT: 11

9TH AVENUE

Poor

Over: SMITH CREEK

077092400, Washington, IA

Built 1928 Load: 21.1 t ADT: 920

LOCAL

Poor

Over: SMITH CREEK

077092406, Washington, IA

Built 1930 Load: 21.1 t ADT: 110

FM

Poor

Over: N. FORK LONG CREEK

076073304, Washington, IA

Built 1961 Load: 21.8 t ADT: 440

FM

Poor

Over: SMALL STREAM

077061903, Washington, IA

Built 1925 Load: 21.9 t ADT: 270

LOCAL ROAD

Poor

Over: WEST FORK CROOKED CREEK

076092801, Washington, IA

Built 1949 Load: 23.3 t ADT: 26

FM

Poor

Over: WILLIAMS CREEK

074073404, Washington, IA

Built 1936 Load: 24.5 t ADT: 1,650

LOCAL

Poor

Over: GOOSE CREEK

076062401, Washington, IA

Built 1975 Load: 24.5 t ADT: 26

LOCAL

Poor

Over: N FORK LONG CR

075070103, Washington, IA

Built 1973 Load: 25.4 t ADT: 60

LOCAL ROAD

Poor

Over: WHISKEY CREEK

076063202, Washington, IA

Built 1969 Load: 25.4 t ADT: 71

CO RD W64

Poor

Over: LONG CREEK

075062214, Washington, IA

Built 1929 Load: 25.9 t ADT: 140

FM

Poor

Over: DUTCH CREEK

075091804, Washington, IA

Built 1956 Load: 26.9 t ADT: 45

LOCAL ROAD

Poor

Over: WHISKEY CREEK

076062604, Washington, IA

Built 1929 Load: 27.8 t ADT: 20

LOCAL ROAD

Poor

Over: SMALL STREAM

076091501, Washington, IA

Built 1927 Load: 28.1 t ADT: 26

FM

Poor

Over: SMALL STREAM

077090708, Washington, IA

Built 1927 Load: 29.8 t ADT: 45

FM

Poor

Over: BR ENGLISH RIVER

077091703, Washington, IA

Built 1927 Load: 29.8 t ADT: 40

FM

Poor

Over: SM STREAM

075093109, Washington, IA

Built 1928 Load: 31.7 t ADT: 10

Read our methodology - how this data is sourced, computed, and verified.

Related

Browse all → | Rankings →
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges

Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.