County profile · official public datasets

Benton County, OR

190 public highway bridges tracked in the FHWA National Bridge Inventory: 32.6% rated Good, 60% Fair, 7.4% Poor.

190
Public bridges: 32.6%
Good condition: 7.4%
Poor condition

The verdict

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

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

30th
of 36 on Poor share: 7.4%
Poor-condition share: 190
public highway bridges: 1974
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.

Benton County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Benton County ranks #30 of 36 Oregon counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 7.4%). Benton County, Oregon contains 190 public highway bridges. Roughly 32.6% are rated “Good,” 60% “Fair,” and 7.4% “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.

Total bridges

190

Public highway bridges in Benton County

Good condition

32.6%

62 of 190 rated 7-9

Fair condition

60%

114 of 190 rated 5-6

Poor condition

7.4%

14 of 190 rated 4 or below

In-state Poor-share rank

#30 of 36

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

Condition distribution

Share of 190 NBI-tracked bridges by lowest applicable component rating.

Good

32.6% (62)

Fair

60% (114)

Poor

7.4% (14)

Benton County's Poor-condition bridges carry 28,587 vehicle crossings a day

That is 5.3% of the county's reported daily bridge traffic on 7.4% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 2,042 crossings a day against 2,572 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 190 of 190 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

59.5% of Benton County's bridges have passed the 50-year mark

113 of the 190 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 32.6% 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 34.7% of the county's Poor-condition bridge traffic

HWY 210 EB over Willamette River, built 1913, carries 9,913 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 14-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 28,587 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1910s

2
1920s

6
1930s

5
1940s

6
1950s

30
1960s

57
1970s

18
1980s

12
1990s

13
2000s

21
2010s

18
2020s

2

What this shows Construction peaked in the 1960s, when 57 of the county's bridges still in the inventory were built, which is 30% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1974) matches the Oregon average (1975).

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

The 5 Oregon counties nearest Benton County in number of bridges, with their condition splits. Its 7.4% Poor share is the 6th-lowest of these 6. Its average build year of 1974 against a peer-group mean of 1976 is in line with the group.

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

Bridge inventory size and condition shares for Benton County and the 5 Oregon counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Lincoln County	190	41.6%	51.1%	7.4%	1974
Benton County (this page)	190	32.6%	60%	7.4%	1974
Baker County	188	27.7%	65.4%	6.9%	1972
Malheur County	181	31.5%	65.7%	2.8%	1976
Union County	166	42.2%	54.2%	3.6%	1980
Polk County	161	29.2%	64%	6.8%	1976

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

Similar inventory size

Nearest county inventories outside OR (190 bridges here).

Clinton County, IL · 190 bridges
Wapello County, IA · 190 bridges
Webster County, IA · 190 bridges
Bienville County, LA · 190 bridges

Similar average build year

Nearest mean year-built outside OR (1974 here).

Knox County, TN · avg 1974 · 588 bridges
Summit County, OH · avg 1974 · 563 bridges
Onondaga County, NY · avg 1974 · 472 bridges
Orange County, NY · avg 1974 · 472 bridges

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

All 190 Good 62 Fair 114 Poor 14

All bridges (190)

Sort:

Benton County Bridge Snapshot

Condition distribution

Benton County's Poor-condition bridges carry 28,587 vehicle crossings a day

59.5% of Benton County's bridges have passed the 50-year mark

One structure carries 34.7% of the county's Poor-condition bridge traffic

How Benton 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

All bridges (190)

US 20 (HWY 33)

Hwy 201

AIRPORT RD

GRANGE HALL RD

GREENBERRY RD

BEAVER CREEK RD

CHAPEL DR

14 S 08 W 03.01:

BELLFOUNTAIN RD

ALPINE RD

NW 9TH ST

SE CRYSTAL LAKE DR

OR 99W (HWY 1W) SB

OLD RIVER RD

ROAD

SW MORRIS AVE

Washington Way

BELLFOUNTAIN RD

KNOLLBROOK PL

NW ELMWOOD DRIVE

FAIR OAKS DR

OR 99W (Hwy 91)

HWY 091

14 S 06 W 34.01:

SW BROOKLANE DR.

14 S 07 W 19.00:

DODGE ISLAND RD

HWY 210 EB

HAYDEN ROAD

FOSTER RD

WILES ROAD

WILLIAMS RD

MC FARLAND RD

NW GARFIELD AVE

OR 34 (Hwy 210) WB

FIRCREEK LANE

TAMPICO ROAD

ROBISON RD

ALEXANDER ROAD

NW GRANT ST

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