Total bridges
326
Public highway bridges in Washington County
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.
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
- 1920s 5
1920–1929
5 bridges
- 1930s 6
1930–1939
6 bridges
- 1940s 10
1940–1949
10 bridges
- 1950s 24
1950–1959
24 bridges
- 1960s
1960–1969
41 bridges
- 1970s
1970–1979
68 bridges
- 1980s
1980–1989
38 bridges
- 1990s
1990–1999
37 bridges
- 2000s
2000–2009
57 bridges
- 2010s 25
2010–2019
25 bridges
- 2020s 15
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.
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.
| 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.
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).
- Miami County, KS · 326 bridges
- Montgomery County, KS · 326 bridges
- Merrimack County, NH · 326 bridges
- St. Clair County, MI · 327 bridges
Similar average build year
Nearest mean year-built outside OR (1983 here).
- Dallas County, TX · avg 1983 · 3,230 bridges
- Bexar County, TX · avg 1983 · 2,342 bridges
- Sedgwick County, KS · avg 1983 · 1,333 bridges
- Will County, IL · avg 1983 · 649 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
All bridges (326)
VERNONIA RD
FairOver: NEHALEM RIVER
002 MI N SUNSET HWY, Washington, OR
Built 2006 Load: 39.9 t ADT: 367
HWY 144AP
FairOver: ALLEN BLVD
0.3 MI S OF CABOT ST, Washington, OR
Built 2023 Load: 40.8 t ADT: 19,471
HWY 144AR
FairOver: ALLEN BLVD
0.3 MI S OF CABOT ST, Washington, OR
Built 2023 Load: 40.8 t ADT: 19,471
MEACHAM ROAD
FairOver: E FORK DAIRY CREEK
002 MI W DAIRY CREEK ROAD, Washington, OR
Built 2011 Load: 41.5 t ADT: 152
NW SHADYBROOK ROAD
FairOver: MCKAY CREEK
027 MI NE OF NORTH PLAINS, Washington, OR
Built 1983 Load: 41.7 t ADT: 3,925
SW BUTNER ROAD
FairOver: CEDAR MILL CREEK
0107 MI E MURRAY BLVD, Washington, OR
Built 1987 Load: 41.7 t ADT: 5,241
HWY 1NB TO HWY 144
FairOver: I-5 (HWY 001)
2.63 MI N OF TUALATIN RV, Washington, OR
Built 2001 Load: 42.1 t ADT: 25,204
SW SEIFFERT RD
FairOver: HEATON CREEK
0.5 MI SOUTH HWY 219, Washington, OR
Built 1972 Load: 42.6 t ADT: 1,147
114TH Ave
FairOver: Beaverton Creek
114TH Ave, Washington, OR
Built 2008 Load: 42.8 t ADT: 1,500
RITCHEY ROAD
FairOver: GALES CREEK
012 MI E STRINGTOWN RD, Washington, OR
Built 1985 Load: 42.8 t ADT: 749
OR 217 (HWY 144)
FairOver: ASHBROOK CREEK
0.8 MI N OF HWY 1W, Washington, OR
Built 1970 Load: 43.1 t ADT: 97,018
NW DAIRY CREEK RD
FairOver: E FORK DAIRY CREEK
006 MI N MOUNTAINDALE RD, Washington, OR
Built 1969 Load: 43.1 t ADT: 1,572
OR 47 (Hwy 102)
FairOver: Dairy Creek Overflow
1.0 MI N BANKS, Washington, OR
Built 2006 Load: 44.1 t ADT: 3,391
US 26 (Hwy 047)CON
FairOver: Hwy 29 Canyon Road
3.7 MI W OF PORTLAND CC, Washington, OR
Built 2002 Load: 44.7 t ADT: 5,587
I-5 (HWY 001) SB
FairOver: I-5 SB CONN TO I-205 NB
1.4 MI S OF TUALATIN R., Washington, OR
Built 1969 Load: 45.0 t ADT: 63,620
I-5 NB TO I-205 NB
FairOver: I-5 SB CONN TO I-205 NB
1.5 MI S OF TUALATIN R., Washington, OR
Built 1969 Load: 45.0 t ADT: 16,800
SW 135th Avenue
FairOver: Summer Creek
0.2 mi S of Scholls Fy Rd, Washington, OR
Built 1996 Load: 45.0 t ADT: 1,272
NE Airport Rd
FairOver: Dawson Cr
009 MI EAST OF 264TH AVE, Washington, OR
Built 2006 Load: 45.4 t ADT: 54
DENNEY RD ACCESS N
FairOver: FANNO CREEK
001 N OF DENNEY RD, Washington, OR
Built 1977 Load: 45.4 t ADT: 16
DENNEY RD ACCESS S
FairOver: FANNO CREEK
001 S OF DENNEY RD, Washington, OR
Built 1977 Load: 45.4 t ADT: 2,125
VERNONIA RD
FairOver: ROBINSON CREEK
1.4 NO. HWY 26/CO. 9 JCT, Washington, OR
Built 1960 Load: 46.1 t ADT: 378
HARRINGTON ROAD
FairOver: E FK DAIRY CREEK
008 MI E ROY ROAD, Washington, OR
Built 1985 Load: 47.2 t ADT: 809
COCHRAN RD
FairOver: NEHALEM RIVER
016 MI W TIMBER RD, Washington, OR
Built 1980 Load: 47.2 t ADT: 194
CABOT STREET
FairOver: HWY 144
0.3 MI N OF HWY 29, Washington, OR
Built 1971 Load: 47.3 t ADT: 1,987
HARRINGTON ROAD
FairOver: BLEDSOE CREEK
010 MILE EAST OF ROY, Washington, OR
Built 1985 Load: 48.1 t ADT: 809
US 26 (HWY 047)
FairOver: West Fork Dairy Creek
7.1 MI W HWY 37 JCT, Washington, OR
Built 2013 Load: 49.2 t ADT: 11,433
SW MURRAY BLVD
FairOver: CEDAR MILL CREEK
1 MI S/O HWY #26, Washington, OR
Built 1987 Load: 49.9 t ADT: 28,683
US 26 (HWY 047)
FairOver: Ghost Creek
17.3 MI W OF Portland CC, Washington, OR
Built 2012 Load: 50.5 t ADT: 36,756
I-5 (HWY 001) NB
FairOver: I-5 SB CONN TO I-205 NB
14 MI S OF TUALATIN RIVER, Washington, OR
Built 1969 Load: 50.9 t ADT: 63,620
BROOKWOOD AVE
FairOver: TRI MET LIGHT RAIL TRACK
2.2 MI N TV HWY., Washington, OR
Built 2001 Load: 51.7 t ADT: 11,788
S W BONITA ROAD
FairOver: FANNO CREEK
005 MI WEST INTERSTATE 5, Washington, OR
Built 1971 Load: 52.2 t ADT: 12,041
SCHOLLS FERRY RD
FairOver: FANNO CREEK
020 MI SE BEAVERTON CC, Washington, OR
Built 2012 Load: 52.8 t ADT: 18,966
I-5 (HWY 001) SB
FairOver: BEAVER DAM CREEK
0.5 MI S OF TUALATIN R., Washington, OR
Built 1975 Load: 53.1 t ADT: 69,744
HWY 141
FairOver: TUALATIN RIVER
4.0 MI N OF HWY 1, Washington, OR
Built 1967 Load: 53.5 t ADT: 20,550
OR 6 (Hwy 037)
FairOver: South Fork Gales Creek
120 MI W OF HWY 47 JCT, Washington, OR
Built 1956 Load: 54.4 t ADT: 5,608
TIMBER ROAD
FairOver: BEAVER CREEK
NORTH OF GLENWOOD, Washington, OR
Built 2006 Load: 55.3 t ADT: 4,371
NORTHRUP ROAD
FairOver: MCKAY CREEK
006 MI W DIXIE MOUNTAIN, Washington, OR
Built 2000 Load: 56.2 t ADT: 231
RIVER RD
FairOver: ROCK CREEK
00.1 EAST ROOD BR ROAD, Washington, OR
Built 2009 Load: 57.3 t ADT: 10,661
TIMBER ROAD
FairOver: BEAVER CREEK
NORTH OF GLENWOOD, Washington, OR
Built 2001 Load: 59.9 t ADT: 4,243
209TH AVE
FairOver: BUTTERNUT CREEK
0.6 mi W of Br.671214, Washington, OR
Built 2009 Load: 63.2 t ADT: 13,751
ROY ROGERS RD.
FairOver: CHICKEN CREEK
005 MI NW HWY 99, Washington, OR
Built 2000 Load: 64.4 t ADT: 15,717
HWY 140
FairOver: CAMPBELLS CREEK
AT HWY 142 JCT, Washington, OR
Built 2007 Load: 64.5 t ADT: 4,161
Cornelius Pass Rd
FairOver: Hall Creek
MP 1.70 Cornelius Pass Rd, Washington, OR
Built 2010 Load: 65.4 t ADT: 25,168
US 26 (HWY 047) CO
FairOver: BARNES RD CONN
5.1 MI W OF PORTLAND CC, Washington, OR
Built 1985 Load: 68.7 t ADT: 13,259
US 26 (Hwy 047) WB
FairOver: Bledsoe Creek
20.0 MI W OF PORTLAND CC, Washington, OR
Built 1946 Load: 69.0 t ADT: 11,519
HWY 29
FairOver: JOHNSON CREEK
055 MI E HILLSBORO CC, Washington, OR
Built 1983 Load: 69.0 t ADT: 36,092
US 26 (Hwy 047)CON
FairOver: Light Rail Transit
HWY 47 WB TO HWY 144 SB, Washington, OR
Built 1996 Load: 69.0 t ADT: 57,973
OR 217(Hwy 144)CON
FairOver: Light Rail Transit
Hwy 144 NB to Hwy 47 WB, Washington, OR
Built 1996 Load: 69.0 t ADT: 22,716
CORNELL ROAD
FairOver: ROCK CREEK
W of John Olsen Ave, Washington, OR
Built 2001 Load: 69.0 t ADT: 24,439
US 26 (Hwy 047)
FairOver: Cedar Hills Blvd
6.2 MI W OF PORTLAND CC, Washington, OR
Built 2006 Load: 69.0 t ADT: 65,370
Read our methodology - how this data is sourced, computed, and verified.
Related
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.