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.
Fair-condition bridges (202)
SW MURRAY BLVD SB
FairOver: BNRR & TERMAN ROAD
005 MI N HWY 8, Washington, OR
Built 1966 Load: 7.1 t ADT: 15,795
Cornell Road
FairOver: Hwy 47 US 26
8.6 MI W OF PORTLAND CC, Washington, OR
Built 1993 Load: 7.8 t ADT: 24,495
OLD TV HWY #47
FairOver: CARPENTER CREEK
007 MI S FOREST GROVE, Washington, OR
Built 1953 Load: 11.0 t ADT: 1,230
REIN ROAD
FairOver: CEDAR CREEK
010 MI SOUTH HWY 99, Washington, OR
Built 1978 Load: 12.0 t ADT: 214
US 26 (HWY 047)
FairOver: Nehalem River
15.6 MI W OF HWY 37 JCT, Washington, OR
Built 1940 Load: 13.0 t ADT: 6,936
Fern Flat Rd.
FairOver: Roundy Creek
3.18 Mile N Snooseville C, Washington, OR
Built 2010 Load: 13.3 t ADT: 33
170TH AVE
FairOver: BEAVERTON CREEK
0055 MI N HWY-8, Washington, OR
Built 1969 Load: 13.6 t ADT: 18,596
BOHMANN PARKWAY
FairOver: FANNO CREEK
002 MI EAST OF 92ND AVE, Washington, OR
Built 1957 Load: 13.9 t ADT: 282
NICOL RD
FairOver: FANNO CREEK
003 MI S SCHOLLS FERRY RD, Washington, OR
Built 1962 Load: 14.3 t ADT: 3,115
SW 229th AVE
FairOver: BUTTERNUT CREEK
008 MI N ROSEDALE ROAD, Washington, OR
Built 1978 Load: 14.3 t ADT: 3,850
Hwy 029
FairOver: Dairy Creek
2.9 MI E FOREST GROVE, Washington, OR
Built 1923 Load: 14.6 t ADT: 28,205
PADGETT ROAD
FairOver: OVERFLOW MCKAY CREEK
0085 W CONNELL ST, Washington, OR
Built 1963 Load: 14.6 t ADT: 765
LOMBARD EXTENSION
FairOver: BEAVERTON CREEK
001 NORTH OF CANYON ROAD, Washington, OR
Built 1988 Load: 14.6 t ADT: 2,833
OR 217 (HWY 144)
FairOver: HWY 29 TV HWY
1.0 MI N OF ALLEN BLVD, Washington, OR
Built 1971 Load: 14.9 t ADT: 100,512
I-5 (HWY 001) CON
FairOver: BEAVER DAM CREEK
0.4 MI S OF TUALATIN R., Washington, OR
Built 1991 Load: 14.9 t ADT: 9,677
72ND AVE
FairOver: HWY 144
0.8 MI S OF HWY 1-W, Washington, OR
Built 1967 Load: 15.2 t ADT: 102,600
HWY 141
FairOver: OR 217 (HWY 144)
0.3 MI N OF HWY 1-W, Washington, OR
Built 1966 Load: 15.6 t ADT: 11,920
185TH AVE
FairOver: BUTTERNUT CREEK
001 MI W MADELINE STREET, Washington, OR
Built 1974 Load: 15.6 t ADT: 21,545
FERN FLAT ROAD
FairOver: EAST FORK DAIRY CREEK
013 MI N GREENER ROAD, Washington, OR
Built 1975 Load: 15.6 t ADT: 28
SW 86TH AVE
FairOver: FANNO CREEK
002 MI S SCHOLLS FERRY RD, Washington, OR
Built 1960 Load: 15.9 t ADT: 282
EVERS ROAD
FairOver: W.FK.DAIRY CR. OFLOW
009 MI S REILING ROAD, Washington, OR
Built 1957 Load: 15.9 t ADT: 307
HWY 91 SB
FairOver: TUALATIN RIVER
0.5 MI S OF KING CITY CC, Washington, OR
Built 1929 Load: 16.2 t ADT: 13,883
OR 6 (Hwy 037)
FairOver: Gales Creek
13.0 MI W OF HWY 47 JCT, Washington, OR
Built 1956 Load: 16.2 t ADT: 4,731
OR 99W(HWY 001W)NB
FairOver: ROCK CREEK (ONION FLAT)
014 MI N SHERWOOD, Washington, OR
Built 1955 Load: 16.5 t ADT: 14,438
US 26 (HWY 047) WB
FairOver: PNWR & VADIS
17.0 MI W PORTLAND SWCL, Washington, OR
Built 1946 Load: 16.5 t ADT: 11,519
Hwy 29
FairOver: PNWR & Scoggin Creek
1.5 MI N GASTON PO, Washington, OR
Built 1967 Load: 16.5 t ADT: 10,615
HWY 91
FairOver: PNWR
AT TIGARD CC, Washington, OR
Built 1940 Load: 16.8 t ADT: 34,462
DENNY RD & RAMP
FairOver: HWY 144
2.8 MI NW TIGARD CC, Washington, OR
Built 1978 Load: 17.2 t ADT: 2,687
SW 92ND AVE
FairOver: FANNO CREEK
003 MI S SCHOLLS FERRY RD, Washington, OR
Built 1970 Load: 17.2 t ADT: 16,592
US 26 (Hwy 047)
FairOver: Hwy 102 Davies/PTB
4.0 MI W HWY 37 JCT, Washington, OR
Built 1941 Load: 17.5 t ADT: 10,553
CORNELIUS PASS RD
FairOver: ROCK CREEK
007 MI N GERMANTOWN ROAD, Washington, OR
Built 1950 Load: 17.5 t ADT: 9,915
HAINES ROAD
FairOver: I-5 (HWY 001)
3.5 MI N OF TUALATIN RV, Washington, OR
Built 1985 Load: 17.8 t ADT: 8,949
COCHRAN RD
FairOver: NEHALEM RIVER
029 MI W TIMBER ROAD JCT, Washington, OR
Built 1979 Load: 17.8 t ADT: 138
HWY 91
FairOver: FANNO CREEK
AT TIGARD CC, Washington, OR
Built 1940 Load: 18.1 t ADT: 34,462
TIGARD STREET
FairOver: FANNO CREEK
0005 WEST OF TIEDEMAN, Washington, OR
Built 1958 Load: 18.1 t ADT: 5,667
SW WILSHIRE
FairOver: HWY 144
1.3 MI N OF HWY 29, Washington, OR
Built 1971 Load: 18.5 t ADT: 22,288
HWY 141
FairOver: HWY 144
0.1 MI S OF HWY 143 JCT, Washington, OR
Built 1968 Load: 18.5 t ADT: 20,710
OR 99W(HWY 91)SB
FairOver: ROCK CREEK (ONION FLAT)
14 MI. N. OF SHERWOOD, Washington, OR
Built 1931 Load: 19.1 t ADT: 14,438
I-5 (HWY 001)
FairOver: P&W RR
1.1 MI N OF TUALATIN R., Washington, OR
Built 1975 Load: 19.1 t ADT: 135,007
OR 47 (Hwy 102)
FairOver: West Fork Dairy Creek
033 MI N FOREST GROVE, Washington, OR
Built 1937 Load: 19.1 t ADT: 6,860
US 26 (Hwy 047)
FairOver: W FK Dairy Creek
3.2 MI W HWY 47 JCT, Washington, OR
Built 1941 Load: 19.1 t ADT: 10,553
MURRAY BLVD CO
FairOver: HWY 47 US 26
7.2 MI W OF PORTLAND CC, Washington, OR
Built 1991 Load: 19.1 t ADT: 26,185
MOUNTAINDALE ROAD
FairOver: E FK DAIRY CREEK
010 MI N HWY 26, Washington, OR
Built 1992 Load: 19.1 t ADT: 2,066
NW DAIRY CREEK RD
FairOver: E FORK DAIRY CREEK
001 MI E FERN FLAT RD, Washington, OR
Built 1957 Load: 19.1 t ADT: 305
OLD TV HWY #47
FairOver: GASTON SLOUGH
010 W HWY #47, Washington, OR
Built 1934 Load: 19.1 t ADT: 568
OR 99W (HWY 91)
FairOver: OR 217 (HWY 144)
0.6 MI N OF TIGARD CC, Washington, OR
Built 1967 Load: 19.4 t ADT: 45,472
I-5 (HWY 001)
FairOver: TUALATIN RIVER
AT TUALATIN RIVER, Washington, OR
Built 1975 Load: 19.8 t ADT: 139,488
OR 217 (HWY 144)
FairOver: PNWR
0.4 MI N OF ALLEN BLVD, Washington, OR
Built 1968 Load: 19.8 t ADT: 100,512
OR 217 (HWY 144)
FairOver: HWY 40 ORE 10
0.3 MI N OF SPRR, Washington, OR
Built 1971 Load: 19.8 t ADT: 100,512
OR 6 (Hwy 037)
FairOver: P&W & PTB
1.9 MI W OF HWY 47 JCT, Washington, OR
Built 1954 Load: 20.4 t ADT: 8,243
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.