County profile · official public datasets

Spokane County, WA

307 public highway bridges tracked in the FHWA National Bridge Inventory: 51.1% rated Good, 42% Fair, 6.8% Poor.

307
Public bridges: 51.1%
Good condition: 6.8%
Poor condition

The verdict

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

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

24th
of 39 on Poor share: 6.8%
Poor-condition share: 307
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.

Spokane County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Spokane County ranks #24 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 6.8%). Spokane County, Washington contains 307 public highway bridges. Roughly 51.1% are rated “Good,” 42% “Fair,” and 6.8% “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

307

Public highway bridges in Spokane County

Good condition

51.1%

157 of 307 rated 7-9

Fair condition

42%

129 of 307 rated 5-6

Poor condition

6.8%

21 of 307 rated 4 or below

In-state Poor-share rank

#24 of 39

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

Condition distribution

Share of 307 NBI-tracked bridges by lowest applicable component rating.

Good

51.1% (157)

Fair

42% (129)

Poor

6.8% (21)

Spokane County's Poor-condition bridges carry 143,970 vehicle crossings a day

That is 5.2% of the county's reported daily bridge traffic on 6.8% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 6,856 crossings a day against 7,683 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 307 of 307 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

53.1% of Spokane County's bridges have passed the 50-year mark

163 of the 307 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 51.1% 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 31.7% of the county's Poor-condition bridge traffic

MAPLE STREET over SPOKANE RIVER, built 1958, carries 45,696 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 21-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 143,970 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

7
1920s

8
1930s

6
1940s

6
1950s

39
1960s

66
1970s

38
1980s

26
1990s

27
2000s

34
2010s

38
2020s

10

What this shows Construction peaked in the 1960s, when 66 of the county's bridges still in the inventory were built, which is 21.5% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1978) matches the Washington average (1975).

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

The 5 Washington counties nearest Spokane County in number of bridges, with their condition splits. Its 6.8% Poor share is the 5th-lowest of these 6. Its average build year of 1978 against a peer-group mean of 1972 is 6 years newer.

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

Bridge inventory size and condition shares for Spokane 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	308	39%	50.6%	10.4%	1973
Spokane County (this page)	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 Spokane 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 Spokane County, both outside Washington so the neighborhoods are not the same-state size table above.

Similar inventory size

Nearest county inventories outside WA (307 bridges here).

Jewell County, KS · 307 bridges
Fannin County, TX · 307 bridges
Lamar County, TX · 307 bridges
Rockingham County, NH · 308 bridges

Similar average build year

Nearest mean year-built outside WA (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 307 Good 157 Fair 129 Poor 21

Fair-condition bridges (129)

Sort:

Spokane County Bridge Snapshot

Condition distribution

Spokane County's Poor-condition bridges carry 143,970 vehicle crossings a day

53.1% of Spokane County's bridges have passed the 50-year mark

One structure carries 31.7% of the county's Poor-condition bridge traffic

How Spokane 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 (129)

US 395

I-90

I-90

ROSAMOND AVE

I-90 E-N RAMP

SR 290 W-W RAMP

I-90

GARDEN SPRING RD

US 2

PINE BLUFF ROAD

SR 290

HAYS ROAD

SUMMIT PKWY

1ST AVENUE

US 2

US 2

RIVERSIDE AVENUE

SUNSET BOULEVARD

SPRAGUE AVENUE

MCFARLANE ROAD

SPRAGUE WAY S/B

E BABB RD

ROSAMOND AVENUE

FREYA WAY

SPRAGUE AVENUE

SPRAGUE WAY N/B

MONROE ROAD

I-90

MISSION AVENUE

Related