King County, WA

1,364 public highway bridges

King County Bridge Snapshot

King County, Washington contains 1,364 public highway bridges in the FHWA National Bridge Inventory. Roughly 31% are rated “Good,” 33.4% “Fair,” 3.3% “Poor,” and 3.3% are classified as structurally deficient — the federal designation for spans whose deck, superstructure, or substructure has been rated 4 or below on the 0–9 NBI scale. Structurally deficient does not mean unsafe to cross; it means the bridge is on the priority list for repair or replacement.

Inspections in WA are conducted by certified engineers from the state Department of Transportation on a 24-month cycle, and results are reported back to the FHWA each spring. The list below shows every NBI-tracked bridge in the county, sorted by inventory load rating. Use the “Sort by” controls to surface the lowest-rated spans first, and click any row for full inspection history, traffic counts, and condition trends.

Source: FHWA National Bridge Inventory. See methodology for full definitions.

1,364

Total Bridges

31%

Good

3.3%

Poor

3.3%

Structurally Deficient

Condition Distribution

Good

31% (423)

Fair

33.4% (456)

Poor

3.3% (45)

SD

3.3% (45)

All Bridges (1,364)

Sort:

SR 99

Over: TUKWILA INT'L BLVD

1.8 N JCT I-5, King, WA

Built 1966 ADT: 21,114

S-S RAMP

Over: S 116TH WAY

1.8 N JCT I-5, King, WA

Built 1966 ADT: 1,756

SR 99

Over: TUKWILA INT'L BLVD

1.8 N JCT I-5, King, WA

Built 1966 ADT: 21,114

ABERDEEN AVE NE

Over: SR 900

0.3 E JCT I-405, King, WA

Built 1967 ADT: 24,027

E MARGINAL WAY

Over: SR 599

1.4 N JCT I-5, King, WA

Built 1967 ADT: 40,145

SR 167

Over: SR 516

0.1 E JCT SR 181, King, WA

Built 1967 ADT: 38,206

SR 167

Over: SR 516

0.1 E JCT SR 181, King, WA

Built 1967 ADT: 38,206

SR 167

Over: JAMES ST

0.6 N JCT SR 516, King, WA

Built 1967 ADT: 17,200

12TH AVE S

Over: I-90

0.2 E JCT I-5, King, WA

Built 1968 ADT: 9,982

I-90 RAMP TO I-405

Over: I-90 MAINLINE

JCT I-405, King, WA

Built 1969 ADT: 63,576

W-N RAMP TO I-405

Over: S-W RAMP TO I-90

0.1 E JCT I-405, King, WA

Built 1968 ADT: 12,098

I-90

Over: W-S RAMP RICHARD RD

0.2 E JCT I-405, King, WA

Built 1969 ADT: 20,968

I-90 W-S RAMP

Over: I-90 MAINLINE

JCT I-405, King, WA

Built 1969 ADT: 63,576

I-405

Over: I-90 FACTORIA

JCT I-405, King, WA

Built 1969 ADT: 63,576

I-405 NB HOV

Over: I-90 FACTORIA

JCT I-405, King, WA

Built 1969 ADT: 63,576

I-405 RAMP

Over: EB I-90 RAMP

JCT I-405, King, WA

Built 1969 ADT: 14,083

I-5

Over: N-W RAMP E-N RAMP

2.2 N JCT I-90, King, WA

Built 1967 ADT: 22,473

S 132ND ST PED

Over: SR 509

1.0 N JCT SR 518, King, WA

Built 1968 ADT: 58,437

SR 509

Over: N-N RAMP

4.0 N JCT SR 518, King, WA

Built 1968 ADT: 43,832

CLOVERDALE ST

Over: SR 509

4.0 N JCT SR 518, King, WA

Built 1968 ADT: 43,832

195TH ST

Over: I-405

0.8 N JCT SR 522, King, WA

Built 1968 ADT: 104,974

NP RY FACTORI

Over: INTERSTATE ROUTE 90

7.0 E JCT I-5, King, WA

Built 1967 ADT: 84,429

I-405

Over: SR 522 SAMMAMISH R

1.3 E JCT SR 527, King, WA

Built 1968 ADT: 24,447

I-405

Over: SR 522 SAMMAMISH R

1.3 E JCT SR 527, King, WA

Built 1968 ADT: 24,447

I-405 N-W RAMP

Over: SAMMAMISH R, I-405, SR 5

8.7 N JCT SR 520, King, WA

Built 1968 ADT: 110,142

SR 522

Over: SAMMAMISH RIVER

JCT SR 522, King, WA

Built 1968 ADT: 110,142

S 277TH ST

Over: SR 167

3.6 N JCT SR 18, King, WA

Built 1968 ADT: 112,926

I-90

Over: SR 906 W-W RAMP

JCT I-90, King, WA

Built 1969 ADT: 1,148

160TH/BRICKYARD RD

Over: I-405

7.8 N JCT SR 520, King, WA

Built 1969 ADT: 146,349

SR 900

Over: I-90

6.0 E JCT I-405, King, WA

Built 1970 ADT: 78,544

S136TH ST

Over: SR 509

0.8 N JCT SR 518, King, WA

Built 1969 ADT: 58,437

I-90

Over: MERCER SL

6.4 E JCT I-5, King, WA

Built 1970 ADT: 9,916

I-90

Over: MERCER SLOUGH

6.4 E JCT I-5, King, WA

Built 1940 ADT: 9,916

I-90 S-E RAMP

Over: I-90 MERCER SLOUGH

6.4 E JCT I-5, King, WA

Built 1970 ADT: 136,899

I-90 W-N RAMP

Over: I-90 WBCD

6.4 E JCT I-5, King, WA

Built 1969 ADT: 21,966

NE 124TH ST

Over: I-405

5.5 N JCT SR 520, King, WA

Built 1969 ADT: 127,595

24TH AVE S

Over: SR 518, RAMPS

1.5 E JCT SR 509, King, WA

Built 1970 ADT: 68,142

NE 72ND PLACE

Over: I-405

2.6 N JCT SR 520, King, WA

Built 1970 ADT: 164,679

NE 80TH ST PED

Over: I-405

3.0 N JCT SR 520, King, WA

Built 1970 ADT: 158,156

I-405 NBCD

Over: NE 85TH ST

JCT I-405, King, WA

Built 1970 ADT: 44,198

I-405

Over: NE 85TH ST

JCT I-405, King, WA

Built 1971 ADT: 44,198

I-405

Over: NE 85TH ST

JCT I-405, King, WA

Built 1971 ADT: 44,198

I-405 SBCD

Over: NE 85TH ST

JCT I-405, King, WA

Built 1971 ADT: 44,198

SO 160TH ST

Over: SR 509

6.3 N JCT SR 516, King, WA

Built 1971 ADT: 22,507

S 156TH ST

Over: SR 509

6.5 N JCT SR 516, King, WA

Built 1970 ADT: 35,130

SO 152ND ST

Over: SR 509

6.8 N JCT SR 516, King, WA

Built 1971 ADT: 35,130

SO 146TH ST

Over: SR 509

0.1 N JCT SR 518, King, WA

Built 1970 ADT: 23,969

SR 518

Over: SR 509

7.0 N JCT SR 516, King, WA

Built 1971 ADT: 23,969

S 154TH ST

Over: SR 518

1.9 E JCT SR 509, King, WA

Built 1971 ADT: 51,803

I-405

Over: SE 8TH ST

1.7 N JCT I-90, King, WA

Built 1971 ADT: 19,658

Read our methodology — how this data is sourced, computed, and verified.

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Data sourced from official U.S. government datasets. See our methodology for details. Retrieved and formatted by PlainBridges Editorial

Reviewed byPlainbridges Editorial, Plain Bridges Editorial Team · June 6, 2026