Total bridges
566
Public highway bridges in Linn County
County profile · official public datasets
Linn County, OR
566 public highway bridges tracked in the FHWA National Bridge Inventory: 20.8% rated Good, 61.5% Fair, 17.7% Poor.
- 566
- Public bridges
- 20.8%
- Good condition
- 17.7%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Linn County posts a higher-than-median Poor-condition share among rated counties in the state across large county bridge inventory.
- 36th
- of 36 on Poor share
- 17.7%
- Poor-condition share
- 566
- public highway bridges
- 1971
- 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.
Linn County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Linn County ranks #36 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.7%). Linn County, Oregon contains 566 public highway bridges. Roughly 20.8% are rated “Good,” 61.5% “Fair,” and 17.7% “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
20.8%
118 of 566 rated 7-9
Fair condition
61.5%
348 of 566 rated 5-6
Poor condition
17.7%
100 of 566 rated 4 or below
In-state Poor-share rank
#36 of 36
Among Oregon counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 566 NBI-tracked bridges by lowest applicable component rating.
Good 20.8% (118)
Fair 61.5% (348)
Poor 17.7% (100)
Linn County's Poor-condition bridges carry 80,207 vehicle crossings a day
That is 3.5% of the county's reported daily bridge traffic on 17.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 802 crossings a day against 2,136 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 566 of 566 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
65.7% of Linn County's bridges have passed the 50-year mark
372 of the 566 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 20.8% 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 19% of the county's Poor-condition bridge traffic
US 20 (HWY 16) EB over Lebanon Ditch, built 1921, carries 15,212 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 100-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 80,207 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Linn County's bridges were built
566 bridges with a recorded construction year, grouped by decade
- 1920s 3
1920–1929
3 bridges
- 1930s 17
1930–1939
17 bridges
- 1940s 16
1940–1949
16 bridges
- 1950s
1950–1959
116 bridges
- 1960s
1960–1969
180 bridges
- 1970s
1970–1979
80 bridges
- 1980s 45
1980–1989
45 bridges
- 1990s 32
1990–1999
32 bridges
- 2000s 59
2000–2009
59 bridges
- 2010s 14
2010–2019
14 bridges
- 2020s 4
2020–2029
4 bridges
What this shows Construction peaked in the 1960s, when 180 of the county's bridges still in the inventory were built, which is 31.8% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1971) matches the Oregon average (1975).
How Linn County compares with Oregon's closest counties by inventory size
The 5 Oregon counties nearest Linn County in number of bridges, with their condition splits. Its 17.7% Poor share is the 6th-lowest of these 6. Its average build year of 1971 against a peer-group mean of 1972 is in line with the group.
Showing the 5 closest of 35 Oregon counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Douglas County | 699 | 34% | 62.8% | 3.1% | 1973 |
| Linn County (this page) | 566 | 20.8% | 61.5% | 17.7% | 1971 |
| Multnomah County | 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 |
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 Linn 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 Linn County, both outside Oregon so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside OR (566 bridges here).
- York County, PA · 569 bridges
- Shawnee County, KS · 563 bridges
- Middlesex County, NJ · 563 bridges
- Summit County, OH · 563 bridges
Similar average build year
Nearest mean year-built outside OR (1971 here).
- Wayne County, MI · avg 1971 · 1,026 bridges
- Baltimore County, MD · avg 1971 · 783 bridges
- Washington County, PA · avg 1971 · 655 bridges
- Monmouth County, NJ · avg 1971 · 505 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (118)
GATES BRIDGE RD.
GoodOver: MAD CREEK
0.06 E. Mad Creek Rd., Linn, OR
Built 2013 Load: 53.1 t ADT: 1,082
OR 22 (HWY 162)
GoodOver: N Santiam River
061 MI N HWY 16 OF JCT., Linn, OR
Built 2005 Load: 54.4 t ADT: 3,775
ROAD
GoodOver: ELK CR
NO DATA ENTERED, Linn, OR
Built 1980 Load: 54.7 t ADT: 5
12 S 03 E 16.00:
GoodOver: QUARTZVILLE CREEK
15.5 miles NE of Hwy 20 (, Linn, OR
Built 1966 Load: 54.8 t ADT: 25
HOEFER ROAD
GoodOver: OVERFLOW
010MI WEST I5, Linn, OR
Built 2007 Load: 54.8 t ADT: 232
ROAD
GoodOver: CRESCENT CR
NO DATA ENTERED, Linn, OR
Built 1979 Load: 56.1 t ADT: 5
ROAD
GoodOver: TWO GIRLS CR
NO DATA ENTERED, Linn, OR
Built 1980 Load: 57.0 t ADT: 50
PARRISH LAKE ROAD
GoodOver: N SANTIAM
NO DATA ENTERED, Linn, OR
Built 2011 Load: 58.6 t ADT: 75
ROAD
GoodOver: CANYON CR
NO DATA ENTERED, Linn, OR
Built 1990 Load: 59.0 t ADT: 10
CARMEN RESERVOIR
GoodOver: MCKENZIE RIVER
5.0 MI S JCT HWY.20 & 126, Linn, OR
Built 2010 Load: 59.6 t ADT: 29
ROAD
GoodOver: OWL CR
NO DATA ENTERED, Linn, OR
Built 1990 Load: 59.9 t ADT: 10
NO DATA ENTERED
GoodOver: MID SANTIAM
8.6 NE JCT HWY 20-FS 2047, Linn, OR
Built 1980 Load: 60.8 t ADT: 5
ROAD
GoodOver: BOUNDARY CR
NO DATA ENTERED, Linn, OR
Built 1989 Load: 65.4 t ADT: 10
GOLTRA RD
GoodOver: TRIB.LITTLE OAK CREEK
0140 MILES NORTH OF HWY34, Linn, OR
Built 2002 Load: 69.0 t ADT: 1,471
GOLTRA RD.
GoodOver: OAK CR TRIBUTARY
0050 MILES NORTH OF HWY34, Linn, OR
Built 2002 Load: 69.0 t ADT: 1,854
OR 99E (Hwy 58)
GoodOver: Creek
042 MI S HALSEY, Linn, OR
Built 2008 Load: 69.0 t ADT: 3,840
OR 99E (Hwy 58)
GoodOver: Camous Creek
016 MI N HARRISBURG, Linn, OR
Built 2008 Load: 69.0 t ADT: 3,974
2nd AVE
GoodOver: PERIWINKLE CREEK
0.06 MI WEST OF CLEVELAND, Linn, OR
Built 2008 Load: 69.0 t ADT: 728
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.