County profile · official public datasets

Washington County, ID

80 public highway bridges tracked in the FHWA National Bridge Inventory: 32.5% rated Good, 61.3% Fair, 6.3% Poor.

80
Public bridges
32.5%
Good condition
6.3%
Poor condition

The verdict

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

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

30th
of 44 on Poor share
6.3%
Poor-condition share
80
public highway bridges
1979
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 #30 of 44 Idaho counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.3%). Washington County, Idaho contains 80 public highway bridges. Roughly 32.5% are rated “Good,” 61.3% “Fair,” and 6.3% “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

80

Public highway bridges in Washington County

Good condition

32.5%

26 of 80 rated 7-9

Fair condition

61.3%

49 of 80 rated 5-6

Poor condition

6.3%

5 of 80 rated 4 or below

In-state Poor-share rank

#30 of 44

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

Condition distribution

Share of 80 NBI-tracked bridges by lowest applicable component rating.

Good
32.5% (26)
Fair
61.3% (49)
Poor
6.3% (5)

Washington County's Poor-condition bridges carry 750 vehicle crossings a day

That is 0.9% of the county's reported daily bridge traffic on 6.3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 150 crossings a day against 1,400 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 80 of 80 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

42.5% of Washington County's bridges have passed the 50-year mark

34 of the 80 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 32.5% 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 64% of the county's Poor-condition bridge traffic

STC 8217;COVE ROAD over WEISER RIVER, built 1917, carries 480 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 5-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 750 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

80 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1990s, when 17 of the county's bridges still in the inventory were built, which is 21.3% of those with a recorded year. That cohort is now 25 to 34 years old in the 2024 inventory. Its average build year (1979) matches the Idaho average (1979).

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

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

The 5 Idaho counties nearest Washington County in number of bridges, with their condition splits. Its 6.3% Poor share is the 3rd-lowest of these 6. Its average build year of 1979 against a peer-group mean of 1976 is in line with the group.

Showing the 5 closest of 43 Idaho counties eligible for comparison.

Bridge inventory size and condition shares for Washington County and the 5 Idaho counties closest to it in inventory size
County Bridges Poor
Boise County 88 5.7%
Adams County 87 10.3%
Boundary County 83 9.6%
Gooding County 80 7.5%
Madison County 80 0%
Washington County (this page) 80 6.3%

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 Idaho so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside ID (80 bridges here).

Similar average build year

Nearest mean year-built outside ID (1979 here).

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

All 80 Good 26 Fair 49 Poor 5

All bridges (80)

NO DATA ENTERED

Good

Over: MANN CREEK

NO DATA ENTERED, Washington, ID

Built 1976 Load: 26.6 t ADT: 50

N. CRANE ROAD

Good

Over: GRANGER CREEK

3.5 S. 11.8 E. MIDVALE, Washington, ID

Built 1996 Load: 27.2 t ADT: 60

OLD HWY ROAD

Good

Over: SHE CREEK

0.6 N 2.4 E MIDVALE, Washington, ID

Built 2018 Load: 30.5 t ADT: 90

STC 3006;MANN CRK

Good

Over: GALLOWAY CANAL

0.1 S. 5.4 E. WEISER, Washington, ID

Built 2001 Load: 33.6 t ADT: 180

US 95

Good

Over: ROBERTSON SLOUGH

0.6 S. WEISER SCL, Washington, ID

Built 2017 Load: 35.0 t ADT: 7,600

MANN CK RD 50009

Good

Over: MANN CREEK

NO DATA ENTERED, Washington, ID

Built 1974 Load: 37.9 t ADT: 30

HOPPER ROAD

Good

Over: DEER CREEK

3.5 N. 0.2 W. MIDVALE, Washington, ID

Built 1997 Load: 39.0 t ADT: 30

STC8200;JENKINS RD

Good

Over: GALLOWAY CANAL

0.9 N. 1.2 W. WEISER, Washington, ID

Built 1971 Load: 40.5 t ADT: 810

STC3879;BURTON LN

Good

Over: LITTLE WEISER RIVER

1.8 S. 1.0 E. CAMBRIDGE, Washington, ID

Built 1991 Load: 40.8 t ADT: 190

STC 3888;SUPERIOR

Good

Over: RUSH CREEK

IN CAMBRIDGE, Washington, ID

Built 2009 Load: 40.8 t ADT: 300

US 95

Good

Over: MONROE CREEK

3.8 N. WEISER NBCL, Washington, ID

Built 1990 Load: 41.7 t ADT: 4,400

STC 3888;MILL ROAD

Good

Over: WEISER RIVER

0.5N 1.7E CAMBRIDGE, Washington, ID

Built 2002 Load: 41.7 t ADT: 300

US 95

Good

Over: GALLOWAY CANAL

0.4 N. WEISER NCL, Washington, ID

Built 1999 Load: 42.6 t ADT: 5,800

KEITHLY CREEK ROAD

Good

Over: KEITHLY CREEK

2.5 N. 1.1 W. MIDVALE, Washington, ID

Built 1995 Load: 45.4 t ADT: 30

WEISER RIVER ROAD

Good

Over: WEISER RIVER

1.5 N. 10.0 E. WEISER, Washington, ID

Built 1998 Load: 47.2 t ADT: 240

US 95 SPUR

Good

Over: SNAKE RIVER; WEISER BR

IN WEISER, Washington, ID

Built 2010 Load: 48.1 t ADT: 3,800

STC 8202;W 9TH ST

Good

Over: GALLOWAY CANAL

0.56 N 0.71 W WEISER, Washington, ID

Built 2021 Load: 53.5 t ADT: 280

WEISER RIVER ROAD

Good

Over: GALLOWAY CANAL

0.2 S. 5.8 E. WEISER, Washington, ID

Built 2005 Load: 55.3 t ADT: 240

US 95

Good

Over: MONROE CREEK

IN WEISER, Washington, ID

Built 1999 Load: 58.1 t ADT: 5,800

US 95

Good

Over: PINE CREEK

0.4 S Cambridge SWCL, Washington, ID

Built 2021 Load: 58.6 t ADT: 4,300

STC 8206;E 6TH ST

Good

Over: GALLOWAY CANAL

0.5 N. 0.8 E. WEISER, Washington, ID

Built 1990 Load: 63.5 t ADT: 1,300

STC8215;WEISER RVR

Good

Over: GALLOWAY CANAL

0.3 S. 4.9 E. WEISER, Washington, ID

Built 1993 Load: 74.4 t ADT: 320

W PINE CREEK ROAD

Good

Over: WEST PINE CREEK

1.0 N 4.0 W CAMBRIDGE, Washington, ID

Built 2010 Load: 88.9 t ADT: 50

CUT OFF ROAD

Good

Over: HOG CREEK

3.0 S 9.2 E MIDVALE, Washington, ID

Built 2007 Load: 99.9 t ADT: 90

BED ROCK FLAT ROAD

Good

Over: HOG CREEK

0.5S 9.3E MIDVALE, Washington, ID

Built 2002 Load: 99.9 t ADT: 50

RIVER ROAD

Poor

Over: DIXIE CREEK

3.0 S. 0.3 W. CAMBRIDGE, Washington, ID

Built 1917 Load: 8.2 t ADT: 30

STC 8217;COVE ROAD

Poor

Over: WEISER RIVER

0.4 S. 1.3 E. WEISER, Washington, ID

Built 1917 Load: 10.9 t ADT: 480

SAGE CREEK ROAD

Poor

Over: SAGE CREEK

0.7 S. 1.4 W. MIDVALE, Washington, ID

Built 1965 Load: 15.4 t ADT: 50

STC 3007;UNITY RD

Poor

Over: WEISER RIVER

0.7 S. 5.6 E. WEISER, Washington, ID

Built 1910 Load: 16.3 t ADT: 170

LOWER CRANE ROAD

Poor

Over: CRANE CREEK

3.6 N. 10.3 E. WEISER, Washington, ID

Built 1955 Load: 56.2 t ADT: 20

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

Related

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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.