Total bridges
326
Public highway bridges in Washington County
County profile · official public datasets
326 public highway bridges tracked in the FHWA National Bridge Inventory: 35.6% rated Good, 62% Fair, 2.5% Poor.
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.
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.
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
Share of 326 NBI-tracked bridges by lowest applicable component rating.
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.
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.
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.
326 bridges with a recorded construction year, grouped by decade
1920–1929
5 bridges
1930–1939
6 bridges
1940–1949
10 bridges
1950–1959
24 bridges
1960–1969
41 bridges
1970–1979
68 bridges
1980–1989
38 bridges
1990–1999
37 bridges
2000–2009
57 bridges
2010–2019
25 bridges
2020–2029
15 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.
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.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Jackson County | 401 | 34.2% | 64.3% | 1.5% | 1976 |
| Marion County | 373 | 21.2% | 74.5% | 4.3% | 1971 |
| Clackamas County | 367 | 31.1% | 66.5% | 2.5% | 1975 |
| Washington County (this page) | 326 | 35.6% | 62% | 2.5% | 1983 |
| Umatilla County | 321 | 31.5% | 64.5% | 4% | 1973 |
| Coos County | 254 | 40.9% | 55.9% | 3.1% | 1978 |
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.
Two NBI-derived peer sets for Washington County, both outside Oregon so the neighborhoods are not the same-state size table above.
Nearest county inventories outside OR (326 bridges here).
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.
Over: PWRR
MP 0.445, Washington, OR
Over: BEAVERTON CREEK
001 WEST OF MURRY RD, Washington, OR
Over: WEST FORK DAIRY CREEK
007 MI S REILING ROAD, Washington, OR
Over: GALES CREEK
0025 MI E GALES CREEK RD, Washington, OR
Over: COUNCIL CREEK
0069 MI N HWY 8, Washington, OR
Over: Gales Creek
5.23 MI HILLSBORO CTY LIM, Washington, OR
Over: BETHANY CREEK
0.1 mi. E/O 185TH AVENUE, Washington, OR
Over: DAIRY CREEK TRIB
011 MI W FISHER RD, Washington, OR
Over: E FK DAIRY CREEK
0005 MI E DAIRY CREEK RD, Washington, OR
Over: East Fork Dairy Creek
175 MI W PORTLAND SWCL, Washington, OR
Over: Creek
.75 M S OF VERBOORT RD, Washington, OR
Over: DAIRY CREEK OFLOW
010 MI W HWY 47, Washington, OR
Over: BEAVERTON CREEK
0.14 MI from Cedar Hills, Washington, OR
Over: FANNO CREEK
2.8 MI NW TIGARD CC, Washington, OR
Over: TUALATIN RIVER
018 MI S RIVER ROAD, Washington, OR
Over: Rock Creek
North Plains, Washington, OR
Over: TUALATIN RIVER OVERFLOW
001 MI N TUALATIN RIVER, Washington, OR
Over: SAIN CREEK
0267 MI W SCOGGIN VALLEY, Washington, OR
Over: FANNO CREEK
0.4 M S OF ALLEN BLVD, Washington, OR
Over: FANNO CREEK
2.0 MI SW BEAVERTON CC, Washington, OR
Over: CEDAR MILL CREEK
005 MI W CEDAR HILLS BLVD, Washington, OR
Over: FANNO CREEK
0025 MI SOUTH PACIFIC HWY, Washington, OR
Over: TUALATIN RV TRIBUTARY
.4 MI S OF SCHOLLS FRY RD, Washington, OR
Over: Dairy Creek Overflow
32 MI N FOREST GROVE, Washington, OR
Over: South Fork Dairy Creek
034 MI N FOREST GROVE, Washington, OR
Over: CARPENTER CREEK
001 MI W HWY 47, Washington, OR
Over: WHISKEY CREEK
0045 M I W MEACHAM, Washington, OR
Over: NAYLOR CREEK
00.5 MI SW FOREST GROVE, Washington, OR
Over: LOUSIGNONT CREEK
005 MI SOUTH OF HWY 26, Washington, OR
Over: MCKAY CREEK
002 MI E SHADYBROOK ROAD, Washington, OR
Over: CEDAR MILL CREEK
05 MI WEST MURRAY BLVD, Washington, OR
Over: BLEDSOE CREEK
009 MI N HWY 26, Washington, OR
Over: SMALL STREAM
002 MI W MIDWAY ROAD, Washington, OR
Over: SCOGGINS CREEK
015 MI N PATTON VALLEY RD, Washington, OR
Over: FANNO CREEK
005 MI S HWY 10, Washington, OR
Over: Summer Creek
0.3 mi S of Scholls Fy Rd, Washington, OR
Over: MCKAY CREEK
005 N EVERGREEN ROAD, Washington, OR
Over: FANNO CREEK
15 MI W BOONES FERRY RD., Washington, OR
Over: TUALATIN RIVER
002 SOUTH HWY 47, Washington, OR
Over: ROCK CREEK
010 N TV HWY., Washington, OR
Over: Council Creek
006 MI N HWY 8, Washington, OR
Over: WHITCHER CREEK
005 MI N CASON ROAD, Washington, OR
Over: CEDAR CREEK
CO.RD.# 2080, Washington, OR
Over: GALES CREEK
002 MI N GALES CREEK HWY, Washington, OR
Over: Creek
1.6 M S OF VERBOORT RD, Washington, OR
Over: HWY 47 US 26
17.3 MI W OF PORTLAND CC, Washington, OR
Over: JOHNSON CREEK
0.39 MI W OF MURRAY BLVD, Washington, OR
Over: Cedar Creek
Wash. ST AND Cedar CR, Washington, OR
Over: P&WRR
052 MI E HILLSBORO CC, Washington, OR
Over: CREEK
West Barrows Rd culvert, Washington, OR
Read our methodology - how this data is sourced, computed, and verified.
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.