County profile · official public datasets

Pierce County, WA

472 public highway bridges tracked in the FHWA National Bridge Inventory: 55.3% rated Good, 40.5% Fair, 4.2% Poor.

472
Public bridges: 55.3%
Good condition: 4.2%
Poor condition

The verdict

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

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

Top 36%
lowest Poor share in state: 4.2%
Poor-condition share: 472
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.

Pierce County Bridge Snapshot

According to the Federal Highway Administration's 2024 National Bridge Inventory, Pierce County ranks #14 of 39 Washington counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 4.2%). Pierce County, Washington contains 472 public highway bridges. Roughly 55.3% are rated “Good,” 40.5% “Fair,” and 4.2% “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

472

Public highway bridges in Pierce County

Good condition

55.3%

261 of 472 rated 7-9

Fair condition

40.5%

191 of 472 rated 5-6

Poor condition

4.2%

20 of 472 rated 4 or below

In-state Poor-share rank

#14 of 39

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

Condition distribution

Share of 472 NBI-tracked bridges by lowest applicable component rating.

Good

55.3% (261)

Fair

40.5% (191)

Poor

4.2% (20)

Pierce County's Poor-condition bridges carry 205,202 vehicle crossings a day

That is 2.5% of the county's reported daily bridge traffic on 4.2% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 10,260 crossings a day against 17,689 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 472 of 472 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.

56.6% of Pierce County's bridges have passed the 50-year mark

267 of the 472 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 55.3% 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 13.9% of the county's Poor-condition bridge traffic

SR 99 (54TH AVE E) over I-5 RAMPS, built 1961, carries 28,462 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 20-bridge count understates how much of the daily burden sits on a single crossing.

Share is of the 205,202 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.

1900s

2
1910s

8
1920s

22
1930s

23
1940s

18
1950s

68
1960s

74
1970s

69
1980s

45
1990s

46
2000s

37
2010s

45
2020s

15

What this shows Construction peaked in the 1960s, when 74 of the county's bridges still in the inventory were built, which is 15.7% 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 Washington average (1975).

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

The 5 Washington counties nearest Pierce County in number of bridges, with their condition splits. Its 4.2% Poor share is the 3rd-lowest of these 6. Its average build year of 1974 against a peer-group mean of 1974 is in line with the group.

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

Bridge inventory size and condition shares for Pierce County and the 5 Washington counties closest to it in inventory size
County	Bridges	Good	Fair	Poor	Avg. built
Yakima County	558	58.2%	36.7%	5%	1973
Snohomish County	500	49%	47%	4%	1980
Pierce County (this page)	472	55.3%	40.5%	4.2%	1974
Lewis County	419	39.4%	56.8%	3.8%	1969
Grays Harbor County	363	48.8%	41.9%	9.4%	1978
Whatcom County	354	44.1%	50.6%	5.4%	1970

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

Similar inventory size

Nearest county inventories outside WA (472 bridges here).

Onondaga County, NY · 472 bridges
Orange County, NY · 472 bridges
Multnomah County, OR · 473 bridges
Jasper County, MO · 471 bridges

Similar average build year

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

Knox County, TN · avg 1974 · 588 bridges
Summit County, OH · avg 1974 · 563 bridges

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

All 472 Good 261 Fair 191 Poor 20

Good-condition bridges (261)

Sort:

Pierce County Bridge Snapshot

Condition distribution

Pierce County's Poor-condition bridges carry 205,202 vehicle crossings a day

56.6% of Pierce County's bridges have passed the 50-year mark

One structure carries 13.9% of the county's Poor-condition bridge traffic

How Pierce 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

Good-condition bridges (261)

70TH AVE E

I-5

I-5

SR 512

BURNHAM DR NW

YOMAN RD AI

SR 167

S 25TH ST

TRAFFIC AVE

128 ST E

SOUTH YAKIMA AVE

WRIGHT BLISS RD NW

I-5

I-5

SR 512

SR 512

SR 512

SR 512

SR 410

SOUTH 19TH ST

EAST VALLEY HWY E

SR 16

I-5

I-5

SR 512

SR 512

JACKSON AVE

I-705 SB S-S RAMP

N-N RAMP

B ST E

LOWER BURNETT RD E

OHOP VALLEY RD E

DAY USE ROAD

304 ST E

WARREN DR NW

E. GATE RD/TANK TR

NISQUALLY BR. RD.

PINCUS ROAD

30TH INF REGT RD

NCO BEACH RD

MADIGAN AVENUE

SR 509

PUYALLUP AVE

BRIDGEPORT WY W

OLD NISQUALLY RD

SR 167

SR 162

ROAD

TACOMA AV E

SR 16 W-S RAMP

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