County profile · official public datasets

Kittitas County, WA

308 public highway bridges tracked in the FHWA National Bridge Inventory: 39% rated Good, 50.6% Fair, 10.4% Poor.

308
Public bridges: 39%
Good condition: 10.4%
Poor condition

The verdict

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

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

35th
of 39 on Poor share: 10.4%
Poor-condition share: 308
public highway bridges: 1973
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.

Kittitas County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Kittitas County ranks #35 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 10.4%). Kittitas County, Washington contains 308 public highway bridges. Roughly 39% are rated “Good,” 50.6% “Fair,” and 10.4% “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

308

Public highway bridges in Kittitas County

Good condition

39%

120 of 308 rated 7-9

Fair condition

50.6%

156 of 308 rated 5-6

Poor condition

10.4%

32 of 308 rated 4 or below

In-state Poor-share rank

#35 of 39

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

Condition distribution

Share of 308 NBI-tracked bridges by lowest applicable component rating.

Good

39% (120)

Fair

50.6% (156)

Poor

10.4% (32)

Kittitas County's Poor-condition bridges carry 286,199 vehicle crossings a day

That is 16.4% of the county's reported daily bridge traffic on 10.4% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 8,944 crossings a day against 5,739 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 308 of 308 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

64.6% of Kittitas County's bridges have passed the 50-year mark

199 of the 308 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 39% 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 12% of the county's Poor-condition bridge traffic

I-90 over SR 906, built 1969, carries 34,348 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 32-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 286,199 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

1
1910s

1
1920s

5
1930s

32
1940s

7
1950s

30
1960s

96
1970s

43
1980s

9
1990s

22
2000s

19
2010s

36
2020s

7

What this shows Construction peaked in the 1960s, when 96 of the county's bridges still in the inventory were built, which is 31.2% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1973) matches the Washington average (1975).

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

The 5 Washington counties nearest Kittitas County in number of bridges, with their condition splits. Its 10.4% Poor share is the 6th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1973 is in line with the group.

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

Bridge inventory size and condition shares for Kittitas County and the 5 Washington counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Whatcom County	354	44.1%	50.6%	5.4%	1970
Whitman County	347	52.2%	44.4%	3.5%	1974
Kittitas County (this page)	308	39%	50.6%	10.4%	1973
Spokane County	307	51.1%	42%	6.8%	1978
Grant County	306	63.7%	33.7%	2.6%	1973
Skagit County	254	38.2%	59.4%	2.4%	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 Kittitas 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 Kittitas County, both outside Washington so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside WA (308 bridges here).

Rockingham County, NH · 308 bridges
Surry County, NC · 308 bridges
Falls County, TX · 308 bridges
Mississippi County, AR · 309 bridges

Similar average build year

Nearest mean year-built outside WA (1973 here).

Jefferson County, AL · avg 1973 · 1,068 bridges
Erie County, NY · avg 1973 · 906 bridges
Davidson County, TN · avg 1973 · 832 bridges
Lancaster County, PA · avg 1973 · 801 bridges

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

All 308 Good 120 Fair 156 Poor 32

Fair-condition bridges (156)

Sort:

Kittitas County Bridge Snapshot

Condition distribution

Kittitas County's Poor-condition bridges carry 286,199 vehicle crossings a day

64.6% of Kittitas County's bridges have passed the 50-year mark

One structure carries 12% of the county's Poor-condition bridge traffic

How Kittitas 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

Fair-condition bridges (156)

NO DATA ENTERED

CHRISTENSEN ROAD

U PEOH POINT ROAD

U PEOH POINT ROAD

WESTSIDE ROAD

RED BRIDGE RD

ROSS ROAD

U PEOH POINT ROAD

WATER STREET

WESTSIDE RD

THORP PRAIRIE RD

SOUTH THORP HWY

SOUTH THORP HWY

I-90

I-90

UNIVERSITY WAY

ROBINSON CAN ROAD

EAST TANEUM ROAD

THORP PRAIRIE ROAD

FAIRVIEW ROAD

LIBERTY ROAD

SCHNEBLY ROAD

ROBBINS RD

SMITHSON RD

CLARKE ROAD

THOMAS ROAD

I-90

I-82

PARKE CREEK ROAD

US 97

MOHAR ROAD

OLD HWY 10

SR 821

CANYON ROAD

SR 10

BADGER PKT ROAD

I-82

SR 906

SOUTH CLE ELUM RD

SOUTH THORP HWY

ROAD

OLD HIGHWAY 10

ROAD

BULLFROG ROAD

NORTH THORP HWY

ROAD

UNIVERSITY WAY

RAILROAD AVENUE

I-90

LAMBERT ROAD

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