County profile · official public datasets

Tillamook County, OR

225 public highway bridges tracked in the FHWA National Bridge Inventory: 35.6% rated Good, 59.6% Fair, 4.9% Poor.

225
Public bridges: 35.6%
Good condition: 4.9%
Poor condition

The verdict

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

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

24th
of 36 on Poor share: 4.9%
Poor-condition share: 225
public highway bridges: 1978
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.

Tillamook County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Tillamook County ranks #24 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.9%). Tillamook County, Oregon contains 225 public highway bridges. Roughly 35.6% are rated “Good,” 59.6% “Fair,” and 4.9% “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

225

Public highway bridges in Tillamook County

Good condition

35.6%

80 of 225 rated 7-9

Fair condition

59.6%

134 of 225 rated 5-6

Poor condition

4.9%

11 of 225 rated 4 or below

In-state Poor-share rank

#24 of 36

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

Condition distribution

Share of 225 NBI-tracked bridges by lowest applicable component rating.

Good

35.6% (80)

Fair

59.6% (134)

Poor

4.9% (11)

Tillamook County's Poor-condition bridges carry 19,439 vehicle crossings a day

That is 4.1% of the county's reported daily bridge traffic on 4.9% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 1,767 crossings a day against 1,599 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 225 of 225 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

45.3% of Tillamook County's bridges have passed the 50-year mark

102 of the 225 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 55.1% of the county's Poor-condition bridge traffic

US101 (HWY 9) over Kilchis R. & Possetti Rd, built 1952, carries 10,718 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 11-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 19,439 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

4
1920s

5
1930s

13
1940s

16
1950s

22
1960s

27
1970s

29
1980s

29
1990s

14
2000s

27
2010s

23
2020s

16

What this shows Construction peaked in the 1970s, when 29 of the county's bridges still in the inventory were built, which is 12.9% of those with a recorded year. That cohort is now 45 to 54 years old in the 2024 inventory. Its average build year (1978) matches the Oregon average (1975).

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

The 5 Oregon counties nearest Tillamook County in number of bridges, with their condition splits. Its 4.9% Poor share is the 3rd-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1975 is in line with the group.

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

Bridge inventory size and condition shares for Tillamook County and the 5 Oregon counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Coos County	254	40.9%	55.9%	3.1%	1978
Klamath County	248	46%	48.8%	5.2%	1979
Josephine County	226	35%	62.4%	2.7%	1971
Tillamook County (this page)	225	35.6%	59.6%	4.9%	1978
Benton County	190	32.6%	60%	7.4%	1974
Lincoln County	190	41.6%	51.1%	7.4%	1974

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

Similar inventory size

Nearest county inventories outside OR (225 bridges here).

Dallas County, AL · 225 bridges
Madison County, IA · 225 bridges
Mahaska County, IA · 225 bridges
Lincoln County, KS · 225 bridges

Similar average build year

Nearest mean year-built outside OR (1978 here).

Orange County, CA · avg 1978 · 1,164 bridges
Sumner County, KS · avg 1978 · 659 bridges
Allen County, IN · avg 1978 · 613 bridges
Livingston County, IL · avg 1978 · 579 bridges

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

All 225 Good 80 Fair 134 Poor 11

Fair-condition bridges (134)

Sort:

Tillamook County Bridge Snapshot

Condition distribution

Tillamook County's Poor-condition bridges carry 19,439 vehicle crossings a day

45.3% of Tillamook County's bridges have passed the 50-year mark

One structure carries 55.1% of the county's Poor-condition bridge traffic

How Tillamook 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 (134)

Miami-Foley Road

US101 (Hwy 9)

BARBER RD

OR 6 (Hwy 037)

FOSS ROAD

ODFW Road

FOSS RD

WILSON RIVER LOOP

OR 53 (HWY 46)

HWY 130

US101 (Hwy 9)

US101 (HWY 9)

OR 6 (Hwy 37)

SOUTH LOMMEN ROAD

POWDER CREEK ROAD

Hwy 130

HWY 130

US101 (Hwy 9)

Hwy 130

HWY 130

HWY 130

US101 (HWY 9)

US101 (HWY 9)

Hwy 131

US101 (Hwy 9)

US101 (HWY 9)

Hwy 131

US101 (HWY 9)

HWY 130

OR 22 (Hwy 32)

US101 (HWY 9)

OR 6 (Hwy 037)

US101 (HWY 9)

OR 6 (Hwy 37)

US101 (Hwy 9)

N. F. NEHALEM RD

BLAINE ROAD

HWY 130

US101 (HWY 9)

US101 (Hwy 9)

US101 (Hwy 9)

US101 (Hwy 9)

OR 22 (Hwy 32)

US101 (Hwy 9)

US101 (Hwy 9)

BLAINE ROAD

US101 (Hwy 9)

OR 22 (Hwy 32)

US101 (Hwy 9)

OR 22 (Hwy 32)

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