County profile · official public datasets

Coos County, OR

254 public highway bridges tracked in the FHWA National Bridge Inventory: 40.9% rated Good, 55.9% Fair, 3.1% Poor.

254
Public bridges: 40.9%
Good condition: 3.1%
Poor condition

The verdict

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

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

Top 47%
lowest Poor share in state: 3.1%
Poor-condition share: 254
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.

Coos County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Coos County ranks #17 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 3.1%). Coos County, Oregon contains 254 public highway bridges. Roughly 40.9% are rated “Good,” 55.9% “Fair,” and 3.1% “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

254

Public highway bridges in Coos County

Good condition

40.9%

104 of 254 rated 7-9

Fair condition

55.9%

142 of 254 rated 5-6

Poor condition

3.1%

8 of 254 rated 4 or below

In-state Poor-share rank

#17 of 36

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

Condition distribution

Share of 254 NBI-tracked bridges by lowest applicable component rating.

Good

40.9% (104)

Fair

55.9% (142)

Poor

3.1% (8)

Coos County's Poor-condition bridges carry 3,922 vehicle crossings a day

That is 0.9% of the county's reported daily bridge traffic on 3.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 490 crossings a day against 830 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 254 of 254 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

47.6% of Coos County's bridges have passed the 50-year mark

121 of the 254 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 40.9% 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 44.2% of the county's Poor-condition bridge traffic

COUNTY RD 7A over HAYNES SLOUGH, built 1971, carries 1,733 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 8-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 3,922 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1920s

2
1930s

7
1940s

4
1950s

14
1960s

58
1970s

68
1980s

38
1990s

21
2000s

29
2010s

8
2020s

5

What this shows Construction peaked in the 1970s, when 68 of the county's bridges still in the inventory were built, which is 26.8% 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 Coos County compares with Oregon's closest counties by inventory size

The 5 Oregon counties nearest Coos County in number of bridges, with their condition splits. Its 3.1% Poor share is the 2nd-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 Coos County and the 5 Oregon counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Coos County (this page)	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	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 Coos 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 Coos County, both outside Oregon so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside OR (254 bridges here).

Manatee County, FL · 254 bridges
Ottawa County, MI · 254 bridges
Wagoner County, OK · 254 bridges
Adams County, PA · 254 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 254 Good 104 Fair 142 Poor 8

Fair-condition bridges (142)

Sort:

Coos County Bridge Snapshot

Condition distribution

Coos County's Poor-condition bridges carry 3,922 vehicle crossings a day

47.6% of Coos County's bridges have passed the 50-year mark

One structure carries 44.2% of the county's Poor-condition bridge traffic

How Coos 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 (142)

COUNTY RD 79G

COUNTY RD 220A

COUNTY RD 145

COUNTY RD 6

COUNTY RD 32

25 S 11 W 28.00:

OR 42 (HWY 035)

COUNTY RD 5A

COUNTY RD 91

LONE PINE LN

TEMPLETON RD

COUNTY RD 189

COUNTY RD 189

OR 42 (HWY 035) WB

NORTH FORK ROAD

OR 42 (HWY 035)

N LAKE RD

27 S 12 W 14.00:

COUNTY RD 186G

COUNTY RD 55G

27 S 10 W 06.01:

COUNTY RD 177G

US101(HWY009)NB

COUNTY RD 83G

US101(HWY009)

COUNTY RD 122G

COUNTY RD 55

FAS A-396

COUNTY RD 202G

NORTH LAKE LANE

OR 42 (HWY 035)

COUNTY RD 156

COUNTY RD 1D

COUNTY RD 1B

COUNTY RD 45

Hwy 8000

Catching Slough Rd

COUNTY RD 55G

Hwy. 2300

US101(HWY009)SB

COUNTY RD 17

27 S 10 W 03.00:

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