County profile · official public datasets

Yamhill County, OR

149 public highway bridges tracked in the FHWA National Bridge Inventory: 24.2% rated Good, 71.1% Fair, 4.7% Poor.

149
Public bridges: 24.2%
Good condition: 4.7%
Poor condition

The verdict

According to the Federal Highway Administration's 2024 National Bridge Inventory.

Yamhill County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.

23rd
of 36 on Poor share: 4.7%
Poor-condition share: 149
public highway bridges: 1975
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.

Yamhill County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Yamhill County ranks #23 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.7%). Yamhill County, Oregon contains 149 public highway bridges. Roughly 24.2% are rated “Good,” 71.1% “Fair,” and 4.7% “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.

Total bridges

149

Public highway bridges in Yamhill County

Good condition

24.2%

36 of 149 rated 7-9

Fair condition

71.1%

106 of 149 rated 5-6

Poor condition

4.7%

7 of 149 rated 4 or below

In-state Poor-share rank

#23 of 36

Among Oregon counties with 5+ bridges, lower share ranks better

Condition distribution

Share of 149 NBI-tracked bridges by lowest applicable component rating.

Good

24.2% (36)

Fair

71.1% (106)

Poor

4.7% (7)

Yamhill County's Poor-condition bridges carry 18,054 vehicle crossings a day

That is 3.5% of the county's reported daily bridge traffic on 4.7% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,579 crossings a day against 4,476 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 149 of 149 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

63.1% of Yamhill County's bridges have passed the 50-year mark

94 of the 149 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 24.2% 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 79.4% of the county's Poor-condition bridge traffic

HWY 140 (OR 219) over Hess Creek, built 1958, carries 14,338 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 7-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 18,054 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

6
1930s

2
1940s

1
1950s

29
1960s

46
1970s

21
1980s

7
1990s

8
2000s

11
2010s

12
2020s

6

What this shows Construction peaked in the 1960s, when 46 of the county's bridges still in the inventory were built, which is 30.9% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1975) matches the Oregon average (1975).

How Yamhill County compares with Oregon's closest counties by inventory size

The 5 Oregon counties nearest Yamhill County in number of bridges, with their condition splits. Its 4.7% Poor share is the 3rd-lowest of these 6. Its average build year of 1975 against a peer-group mean of 1977 is in line with the group.

Showing the 5 closest of 35 Oregon counties eligible for comparison.

Bridge inventory size and condition shares for Yamhill County and the 5 Oregon counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Polk County	161	29.2%	64%	6.8%	1976
Clatsop County	155	32.9%	63.2%	3.9%	1974
Deschutes County	152	56.6%	42.1%	1.3%	1986
Yamhill County (this page)	149	24.2%	71.1%	4.7%	1975
Wasco County	148	31.8%	60.1%	8.1%	1968
Grant County	144	45.1%	49.3%	5.6%	1980

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 Yamhill 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 Yamhill County, both outside Oregon so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside OR (149 bridges here).

Tallapoosa County, AL · 149 bridges
Drew County, AR · 149 bridges
Madison County, AR · 149 bridges
Walker County, GA · 149 bridges

Similar average build year

Nearest mean year-built outside OR (1975 here).

San Bernardino County, CA · avg 1975 · 1,422 bridges
Fulton County, GA · avg 1975 · 775 bridges
Westmoreland County, PA · avg 1975 · 620 bridges
Monroe County, NY · avg 1975 · 615 bridges

Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.

All 149 Good 36 Fair 106 Poor 7

Fair-condition bridges (106)

Sort:

Yamhill County Bridge Snapshot

Condition distribution

Yamhill County's Poor-condition bridges carry 18,054 vehicle crossings a day

63.1% of Yamhill County's bridges have passed the 50-year mark

One structure carries 79.4% of the county's Poor-condition bridge traffic

How Yamhill County compares with Oregon's closest counties by inventory size

Nationwide counties with similar inventory size or average build year

Similar inventory size

Similar average build year

Fair-condition bridges (106)

GRENFELL CO PK RD

OR 18 (Hwy 39)

OR 22 (Hwy 32)

OR 18 (Hwy 39)

OR 18 (Hwy 39)

HACKER ROAD

PIKE ROAD

OR 18 (Hwy 39)

BRIDGE STREET

HILL ROAD SOUTH

OR 99W (Hwy 91) SB

ROCKYFORD ROAD

OR 99W (HWY 91)

OR 18 (Hwy 39)

FORT HILL RD

OR 99W (HWY 91)

WILLAMINA CR RD

GRAND ISLAND ROAD

IRR BIA RTE 4

EAST CR RD

OR 18 (Hwy 39)

OAK RIDGE ROAD

HWY 154

OR 18 (Hwy 39)

WESTSIDE ROAD

OR 18 (Hwy 39)

Hwy 29

OR 18 (Hwy 39) CON

DEJONG RD.

HWY 140 (OR 219)

OR 18 (Hwy 39)

WILEY ROAD

OR 99W (HWY 91) NB

County Road

OR 18 (Hwy 39)

OR 22 (Hwy 32)

GRAND ISLAND ROAD

OR 221 (HWY 150)

CALEB PAYNE RD

ALLEN RD

Fletcher Road

WEST SIDE ROAD

WILLIS ROAD

OR 18 (Hwy 39)

BAKER CREEK RD

NORTH HILL ROAD

IRR BIA RTE 4

STRINGTOWN ROAD

OR 99W (Hwy 91)

ALDERMAN RD

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