County profile · official public datasets

Washington County, OR

326 public highway bridges tracked in the FHWA National Bridge Inventory: 35.6% rated Good, 62% Fair, 2.5% Poor.

326
Public bridges
35.6%
Good condition
2.5%
Poor condition

The verdict

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

Washington County pairs a better-than-median Poor-condition share among rated counties in the state with a newer average build year than the state inventory.

Top 31%
lowest Poor share in state
2.5%
Poor-condition share
326
public highway bridges
1983
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 #11 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.5%). Washington County, Oregon contains 326 public highway bridges. Roughly 35.6% are rated “Good,” 62% “Fair,” and 2.5% “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

326

Public highway bridges in Washington County

Good condition

35.6%

116 of 326 rated 7-9

Fair condition

62%

202 of 326 rated 5-6

Poor condition

2.5%

8 of 326 rated 4 or below

In-state Poor-share rank

#11 of 36

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

Condition distribution

Share of 326 NBI-tracked bridges by lowest applicable component rating.

Good
35.6% (116)
Fair
62% (202)
Poor
2.5% (8)

Washington County's Poor-condition bridges carry 54,681 vehicle crossings a day

That is 1.1% of the county's reported daily bridge traffic on 2.5% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 6,835 crossings a day against 10,980 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 326 of 326 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

38.3% of Washington County's bridges have passed the 50-year mark

125 of the 326 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 35.6% 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 35.6% of the county's Poor-condition bridge traffic

ALLEN BLVD over HWY 144, built 1981, carries 19,471 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 54,681 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

326 bridges with a recorded construction year, grouped by decade

bridges

What this shows Construction peaked in the 1970s, when 68 of the county's bridges still in the inventory were built, which is 20.9% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year is 1983, 8 years newer than the Oregon average of 1975.

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

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

The 5 Oregon counties nearest Washington County in number of bridges, with their condition splits. Its 2.5% Poor share is the 3rd-lowest of these 6. Its average build year of 1983 against a peer-group mean of 1975 is 8 years newer.

Showing the 5 closest of 35 Oregon counties eligible for comparison.

Bridge inventory size and condition shares for Washington County and the 5 Oregon counties closest to it in inventory size
County Bridges Poor
Jackson County 401 1.5%
Marion County 373 4.3%
Clackamas County 367 2.5%
Washington County (this page) 326 2.5%
Umatilla County 321 4%
Coos County 254 3.1%

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

Similar inventory size

Nearest county inventories outside OR (326 bridges here).

Similar average build year

Nearest mean year-built outside OR (1983 here).

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

All 326 Good 116 Fair 202 Poor 8

All bridges (326)

SW Teton Ave

Good

Over: Hedges Creek

0.35 N SW Tual-Sher Rd., Washington, OR

Built 1997 Load: 57.7 t ADT: 567

SW Johnson Sch Rd

Good

Over: Davis Creek

0055 MI N SIMPSON ROAD, Washington, OR

Built 2016 Load: 58.0 t ADT: 590

COLLINS ROAD

Good

Over: MCKAY CREEK

025 MI NW SHADYBROOK, Washington, OR

Built 1997 Load: 58.1 t ADT: 231

OR 6 (Hwy 037)

Good

Over: Bateman Creek

10.77 MI W HWY 47 JCT, Washington, OR

Built 2006 Load: 60.3 t ADT: 5,349

OREGON ST.

Good

Over: ROCK CREEK

OR ST AND ROCK CR, Washington, OR

Built 2001 Load: 66.7 t ADT: 214

198TH AVE

Good

Over: CELEBRITY CREEK

MP 0.93, Washington, OR

Built 2020 Load: 68.0 t ADT: 11,176

Wilshire St

Good

Over: Tri-Met LRT

Wilshire 0.1m S of 047, Washington, OR

Built 1994 Load: 69.0 t ADT: 88,423

OR 217

Good

Over: Tri-Met LRT

OR 217 at MP 0.92, Washington, OR

Built 1994 Load: 69.0 t ADT: 93,867

SW HORIZON BLVD

Good

Over: CREEK

HORIZON CROSSING, Washington, OR

Built 2004 Load: 69.0 t ADT: 3,275

SW Hocken Ave.

Good

Over: BEAVERTON CREEK

0.46 MI from Farmington, Washington, OR

Built 2016 Load: 69.0 t ADT: 7,083

SW Myslony St.

Good

Over: Hedges Creek

Sw Myslony St. MP 0.46, Washington, OR

Built 2018 Load: 69.0 t ADT: 218

OR 47 (Hwy 102)

Good

Over: West Fork Dairy Creek

0.5 MI N BANKS, Washington, OR

Built 2022 Load: 69.0 t ADT: 3,372

198TH AVE

Good

Over: BUTTERNUT CREEK

003 MI N BUTTERNUT ST, Washington, OR

Built 2020 Load: 69.0 t ADT: 11,176

BARNES RD

Good

Over: JOHNSON CREEK

MP 3.04, Washington, OR

Built 1995 Load: 69.0 t ADT: 20,157

NW Lauren Ave.

Good

Over: Unnamed Channel

MP 0.03, Washington, OR

Built 2021 Load: 69.0 t ADT: 100

SW TONKA ROAD

Good

Over: NYBERG CREEK

001 E BOONES FERRY ROAD, Washington, OR

Built 1985 Load: 69.0 t ADT: 567

BASELINE RD

Good

Over: BEAVERTON CREEK

002 MI E 231ST AVE, Washington, OR

Built 2005 Load: 69.6 t ADT: 18,329

BASELINE RD

Good

Over: ROCK CREEK

001 MI E 231ST AVE, Washington, OR

Built 2005 Load: 81.6 t ADT: 16,198

SOUTH ROAD

Poor

Over: TUALATIN RIVER

01.8 MI W MT RICHMOND RD, Washington, OR

Built 1974 Load: 5.2 t ADT: 72

ALLEN BLVD

Poor

Over: HWY 144

0.3 MI S OF CABOT ST, Washington, OR

Built 1981 Load: 14.6 t ADT: 19,471

NORTH DAKOTA ST

Poor

Over: FANNO CREEK

0010 W GREENBURG RD, Washington, OR

Built 1962 Load: 16.5 t ADT: 6,925

US 26 (HWY 047)

Poor

Over: West Fork Dairy Creek

8.1 MI W HWY 37 JCT, Washington, OR

Built 1940 Load: 16.8 t ADT: 11,148

TURK ROAD

Poor

Over: WEST FORK DAIRY CREEK

001 MI N SELL ROAD, Washington, OR

Built 1961 Load: 17.2 t ADT: 208

SW 205TH AVE

Poor

Over: BEAVERTON CREEK

004 MI N BASELINE RD, Washington, OR

Built 1960 Load: 18.8 t ADT: 14,741

UEBEL ROAD

Poor

Over: E FORK DAIRY CREEK

0005 MI W OF PUMPKIN RIDG, Washington, OR

Built 1973 Load: 21.1 t ADT: 1,202

GREENVILLE ROAD

Poor

Over: DAIRY CREEK

014 MI W HWY 47, Washington, OR

Built 1964 Load: 27.2 t ADT: 914

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.