County profile · official public datasets

Adams County, WA

187 public highway bridges tracked in the FHWA National Bridge Inventory: 35.3% rated Good, 54.5% Fair, 10.2% Poor.

187
Public bridges: 35.3%
Good condition: 10.2%
Poor condition

The verdict

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

Adams County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.

34th
of 39 on Poor share: 10.2%
Poor-condition share: 187
public highway bridges: 1961
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.

Adams County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Adams County ranks #34 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.2%). Adams County, Washington contains 187 public highway bridges. Roughly 35.3% are rated “Good,” 54.5% “Fair,” and 10.2% “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

187

Public highway bridges in Adams County

Good condition

35.3%

66 of 187 rated 7-9

Fair condition

54.5%

102 of 187 rated 5-6

Poor condition

10.2%

19 of 187 rated 4 or below

In-state Poor-share rank

#34 of 39

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

Condition distribution

Share of 187 NBI-tracked bridges by lowest applicable component rating.

Good

35.3% (66)

Fair

54.5% (102)

Poor

10.2% (19)

Adams County's Poor-condition bridges carry 63,443 vehicle crossings a day

That is 21.5% of the county's reported daily bridge traffic on 10.2% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 3,339 crossings a day against 1,509 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 186 of 187 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

70.1% of Adams County's bridges have passed the 50-year mark

131 of the 187 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 35.3% 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 16.4% of the county's Poor-condition bridge traffic

I-90 over BNSF RAILROAD, built 1968, carries 10,407 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 19-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 63,443 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

10
1910s

16
1920s

6
1930s

9
1940s

9
1950s

47
1960s

14
1970s

26
1980s

12
1990s

20
2000s

16
2010s

2

What this shows Construction peaked in the 1950s, when 47 of the county's bridges still in the inventory were built, which is 25.1% of those with a recorded year. That cohort is now 65 to 74 years old in the 2024 inventory. Its average build year is 1961, 14 years older than the Washington average of 1975.

How Adams County compares with Washington's closest counties by inventory size

The 5 Washington counties nearest Adams County in number of bridges, with their condition splits. Its 10.2% Poor share is the 6th-lowest of these 6. Its average build year of 1961 against a peer-group mean of 1975 is 14 years older.

Showing the 5 closest of 38 Washington counties eligible for comparison.

Bridge inventory size and condition shares for Adams County and the 5 Washington counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Thurston County	205	59.5%	39.5%	1%	1979
Walla Walla County	195	64.1%	27.2%	8.7%	1980
Adams County (this page)	187	35.3%	54.5%	10.2%	1961
Lincoln County	180	56.7%	37.2%	6.1%	1965
Benton County	167	58.7%	35.9%	5.4%	1977
Okanogan County	161	46.6%	45.3%	8.1%	1972

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

Similar inventory size

Nearest county inventories outside WA (187 bridges here).

Lonoke County, AR · 187 bridges
Huntington County, IN · 187 bridges
Grundy County, MO · 187 bridges
Henry County, TN · 187 bridges

Similar average build year

Nearest mean year-built outside WA (1961 here).

Westchester County, NY · avg 1961 · 774 bridges
Tehama County, CA · avg 1961 · 450 bridges
Berkshire County, MA · avg 1961 · 450 bridges
Schuylkill County, PA · avg 1961 · 368 bridges

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

All 187 Good 66 Fair 102 Poor 19

All bridges (187)

Sort:

US 395

Fair

Over: PAHA-PACKARD RD

5.4 N JCT SR 21, Adams, WA

Built 1995 Load: 63.5 t ADT: 4,747

SR 17

Fair

Over: SR 26

13.7 N JCT SR 260, Adams, WA

Adams County Bridge Snapshot

Condition distribution

Adams County's Poor-condition bridges carry 63,443 vehicle crossings a day

70.1% of Adams County's bridges have passed the 50-year mark

One structure carries 16.4% of the county's Poor-condition bridge traffic

How Adams County compares with Washington'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 (187)

US 395

SR 17

I-90

DAMON RD

I-90

BENGE-WINONA RD

I-90

PROVIDENCE RD

N BOB LEE RD

US 395 (SB ONLY)

ATHEY RD

3RD STREET

SR 261

LIND-RALSTON RD

I-90

MAINTENANCE ROAD

SR 261

BENCH RD

LIND-RALSTON RD

SR 21

RALSTON-BENGE RD

DEAL RD

SR 26

SR 261

PAHA-PACKARD RD

KOCH RD

CUNNINGHAM RD

HEINEMANN RD

ROSENOFF RD

CALLOWAY RD

BOOKER RD

MCMANAMON RD

DEAL RD

LIND-RALSTON RD

HEINEMAN RD

NEILSON ST

CEMETERY RD

US 395

BATUM RD

GRAY RD

BAUER RD

PROVIDENCE RD

VAN MARTER ST

DEAL RD

WELLSANDT RD.

YEISLEY RD

SR 21

I-90

I-90

SR 21

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