Total bridges
473
Public highway bridges in Multnomah County
County profile · official public datasets
Multnomah County, OR
473 public highway bridges tracked in the FHWA National Bridge Inventory: 11.8% rated Good, 85.2% Fair, 3% Poor.
- 473
- Public bridges
- 11.8%
- Good condition
- 3%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Multnomah County pairs a better-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- Top 42%
- lowest Poor share in state
- 3%
- Poor-condition share
- 473
- public highway bridges
- 1967
- 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.
Multnomah County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Multnomah County ranks #15 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3%). Multnomah County, Oregon contains 473 public highway bridges. Roughly 11.8% are rated “Good,” 85.2% “Fair,” and 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.
Good condition
11.8%
56 of 473 rated 7-9
Fair condition
85.2%
403 of 473 rated 5-6
Poor condition
3%
14 of 473 rated 4 or below
In-state Poor-share rank
#15 of 36
Among Oregon counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 473 NBI-tracked bridges by lowest applicable component rating.
Good 11.8% (56)
Fair 85.2% (403)
Poor 3% (14)
Multnomah County's Poor-condition bridges carry 216,393 vehicle crossings a day
That is 1.4% of the county's reported daily bridge traffic on 3% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 15,457 crossings a day against 17,766 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 473 of 473 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
61.5% of Multnomah County's bridges have passed the 50-year mark
291 of the 473 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 11.8% 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 26.6% of the county's Poor-condition bridge traffic
Hwy 001 NB over Columbia River, built 1916, carries 57,550 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 14-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 216,393 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Multnomah County's bridges were built
473 bridges with a recorded construction year, grouped by decade
- 1900s 9
1900–1909
9 bridges
- 1910s 30
1910–1919
30 bridges
- 1920s 17
1920–1929
17 bridges
- 1930s 25
1930–1939
25 bridges
- 1940s 19
1940–1949
19 bridges
- 1950s
1950–1959
50 bridges
- 1960s
1960–1969
107 bridges
- 1970s
1970–1979
63 bridges
- 1980s
1980–1989
61 bridges
- 1990s
1990–1999
44 bridges
- 2000s 28
2000–2009
28 bridges
- 2010s 17
2010–2019
17 bridges
- 2020s 3
2020–2029
3 bridges
What this shows Construction peaked in the 1960s, when 107 of the county's bridges still in the inventory were built, which is 22.6% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1967, 8 years older than the Oregon average of 1975.
How Multnomah County compares with Oregon's closest counties by inventory size
The 5 Oregon counties nearest Multnomah County in number of bridges, with their condition splits. Its 3% Poor share is the 4th-lowest of these 6. Its average build year of 1967 against a peer-group mean of 1975 is 8 years older.
Showing the 5 closest of 35 Oregon counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Linn County | 566 | 20.8% | 61.5% | 17.7% | 1971 |
| Multnomah County (this page) | 473 | 11.8% | 85.2% | 3% | 1967 |
| 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 | 326 | 35.6% | 62% | 2.5% | 1983 |
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 Multnomah 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 Multnomah County, both outside Oregon so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside OR (473 bridges here).
- Onondaga County, NY · 472 bridges
- Orange County, NY · 472 bridges
- Pierce County, WA · 472 bridges
- Jasper County, MO · 471 bridges
Similar average build year
Nearest mean year-built outside OR (1967 here).
- Los Angeles County, CA · avg 1967 · 3,547 bridges
- Allegheny County, PA · avg 1967 · 1,294 bridges
- Sonoma County, CA · avg 1967 · 609 bridges
- Merced County, CA · avg 1967 · 528 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Poor-condition bridges (14)
Hwy 100
PoorOver: Viaduct
0.2 MI W MULTNOMAH FALLS, Multnomah, OR
Built 1914 Load: 4.5 t ADT: 781
FAS A656
PoorOver: SANDY RIVER
040 MI SE TROUTDALE, Multnomah, OR
Built 1914 Load: 11.0 t ADT: 6,445
US26 (HWY 026AC)
PoorOver: ARTHUR ST VIADUCT
1.0 MI SE PORTLAND CC, Multnomah, OR
Built 1947 Load: 13.3 t ADT: 8,795
N BURGARD ST
PoorOver: B-1 OVER UP/SPRR
AT TERMINAL NO 4, Multnomah, OR
Built 1930 Load: 17.5 t ADT: 13,113
Hwy 001 NB
PoorOver: Columbia River
AT INTERSTATE BRIDGE, Multnomah, OR
Built 1916 Load: 18.5 t ADT: 57,550
WILLAMETTE BLVD
PoorOver: BURLINGTON NORTHERN R&R
N. WILLAMETTE OVER BURLIN, Multnomah, OR
Built 1909 Load: 19.1 t ADT: 10,361
FESSENDEN ST
PoorOver: BURLINGTON NORTHERN R&R
FESSENDEN ST. OVER BURLIN, Multnomah, OR
Built 1909 Load: 19.1 t ADT: 4,931
Hwy 123
PoorOver: BNSF
N. LOMBARD ST OVER BURLIN, Multnomah, OR
Built 1909 Load: 19.4 t ADT: 13,970
HWY 1W (STEEL BR)
PoorOver: WILLAMETTE RIVER
0.4 MI NE PORTLAND CC, Multnomah, OR
Built 1910 Load: 19.8 t ADT: 10,362
NW BROADWAY RAMP
PoorOver: BROADWAY ST CONN
WEST END BROADWAY BR, Multnomah, OR
Built 1913 Load: 21.4 t ADT: 30,388
COLUMBIA BLVD
PoorOver: B-78 OVER BNRR
2 MILES NW OF JCT. I-5, Multnomah, OR
Built 1909 Load: 23.3 t ADT: 13,910
COLUMBIA BLVD
PoorOver: B-79 X N. COLUMBIA WAY
N COL BLVD OVER N COL WAY, Multnomah, OR
Built 1968 Load: 27.9 t ADT: 19,379
Hwy 081
PoorOver: UPRR
3.9 MI N PORTLAND CC, Multnomah, OR
Built 1916 Load: 29.2 t ADT: 14,354
I-84 (HWY 002) EB
PoorOver: MCCORD CREEK
5.7 MI W CASCADE LOCKS, Multnomah, OR
Built 1962 Load: 32.4 t ADT: 12,054
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.