Total bridges
99
Public highway bridges in Jefferson County
County profile · official public datasets
Jefferson County, WA
99 public highway bridges tracked in the FHWA National Bridge Inventory: 57.6% rated Good, 38.4% Fair, 4% Poor.
- 99
- Public bridges
- 57.6%
- Good condition
- 4%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Jefferson 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
- 4%
- Poor-condition share
- 99
- public highway bridges
- 1982
- 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.
Jefferson County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Jefferson County ranks #12 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4%). Jefferson County, Washington contains 99 public highway bridges. Roughly 57.6% are rated “Good,” 38.4% “Fair,” and 4% “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
57.6%
57 of 99 rated 7-9
Fair condition
38.4%
38 of 99 rated 5-6
Poor condition
4%
4 of 99 rated 4 or below
In-state Poor-share rank
#12 of 39
Among Washington counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 99 NBI-tracked bridges by lowest applicable component rating.
Good 57.6% (57)
Fair 38.4% (38)
Poor 4% (4)
Jefferson County's Poor-condition bridges carry 20,851 vehicle crossings a day
That is 11.2% of the county's reported daily bridge traffic on 4% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 5,213 crossings a day against 1,843 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 99 of 99 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
43.4% of Jefferson County's bridges have passed the 50-year mark
43 of the 99 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 57.6% 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 84.6% of the county's Poor-condition bridge traffic
SR 104 WESTHALF over HOOD CANAL, built 1982, carries 17,634 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 4-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 20,851 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Jefferson County's bridges were built
99 bridges with a recorded construction year, grouped by decade
- 1910s 1
1910–1919
1 bridges
- 1920s 1
1920–1929
1 bridges
- 1930s
1930–1939
8 bridges
- 1940s 1
1940–1949
1 bridges
- 1950s
1950–1959
9 bridges
- 1960s
1960–1969
14 bridges
- 1970s
1970–1979
15 bridges
- 1980s
1980–1989
11 bridges
- 1990s 4
1990–1999
4 bridges
- 2000s
2000–2009
17 bridges
- 2010s
2010–2019
9 bridges
- 2020s
2020–2029
9 bridges
What this shows Construction peaked in the 2000s, when 17 of the county's bridges still in the inventory were built, which is 17.2% of those with a recorded year. That cohort is now 15 to 24 years old in the 2024 inventory. Its average build year is 1982, 7 years newer than the Washington average of 1975.
How Jefferson County compares with Washington's closest counties by inventory size
The 5 Washington counties nearest Jefferson County in number of bridges, with their condition splits. Its 4% Poor share is the 2nd-lowest of these 6. Its average build year of 1982 against a peer-group mean of 1978 is in line with the group.
Showing the 5 closest of 38 Washington counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Pacific County | 120 | 56.7% | 37.5% | 5.8% | 1974 |
| Skamania County | 120 | 45.8% | 45% | 9.2% | 1974 |
| Kitsap County | 115 | 71.3% | 27.8% | 0.9% | 1989 |
| Jefferson County (this page) | 99 | 57.6% | 38.4% | 4% | 1982 |
| Klickitat County | 90 | 24.4% | 67.8% | 7.8% | 1975 |
| Columbia County | 86 | 45.3% | 44.2% | 10.5% | 1979 |
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 Jefferson 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 Jefferson County, both outside Washington so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside WA (99 bridges here).
- Washington County, FL · 99 bridges
- Crisp County, GA · 99 bridges
- Harris County, GA · 99 bridges
- Newton County, GA · 99 bridges
Similar average build year
Nearest mean year-built outside WA (1982 here).
- Oklahoma County, OK · avg 1982 · 1,216 bridges
- Jackson County, MO · avg 1982 · 930 bridges
- Milwaukee County, WI · avg 1982 · 893 bridges
- Champaign County, IL · avg 1982 · 727 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (57)
UPPER HOH ROAD
GoodOver: UNNAMED CREEK
6.95 E JCT SR 101, Jefferson, WA
Built 2016 Load: 53.5 t ADT: 877
US 101
GoodOver: STEAMBOAT CREEK
7.8 N GRAYS HBR CO, Jefferson, WA
Built 2021 Load: 55.7 t ADT: 1,165
EAST QUILCENE ROAD
GoodOver: DONOVAN CREEK
0.77 E. JCT. CENTER RD, Jefferson, WA
Built 2006 Load: 56.7 t ADT: 513
US 101
GoodOver: WALKERS CREEK
22.0 S JCT SR 104, Jefferson, WA
Built 2008 Load: 57.1 t ADT: 3,222
SOUTH POINT ROAD
GoodOver: SHINE CREEK
0.25 S. JCT. SR104, Jefferson, WA
Built 2005 Load: 61.6 t ADT: 1,215
Thorndyke Road
GoodOver: Thorndyke Creek
4.71 S JCT SOUTH POINT RD, Jefferson, WA
Built 2022 Load: 66.1 t ADT: 492
US 101
GoodOver: FISHER CREEK
3.1 N GRAYS HBR CO, Jefferson, WA
Built 2020 Load: 66.7 t ADT: 1,092
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.