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 18

Over: SR 516

4.1 E JCT SR 515, King, WA

Built 1997 ADT: 26,572

SR 519

Over: STADIUM,BNSFRR,4TH AVE

0.2 W JCT I-90, King, WA

Built 2002 ADT: 12,840

S-E RAMP

Over: 4TH AVENUE

0.2 W JCT I-90, King, WA

Built 2003 ADT: 6,420

256TH ST

Over: SR 18

1.5 E JCT SR 516, King, WA

Built 2002 ADT: 33,566

E-E RAMP

Over: N-E RAMP FROM FRONT ST

2.1 E JCT SR 900, King, WA

Built 2003 ADT: 5,668

HIGHLANDS DR

Over: I-90, E FK ISSAQUAH CR

2.1 E JCT SR 900, King, WA

Built 2003 ADT: 59,685

E-N RAMP

Over: I-90, HIGHLANDS DR

2.1 E JCT SR 900, King, WA

Built 2003 ADT: 59,685

S-S RAMP

Over: SR 167, RAMP

JCT I-405, King, WA

Built 2002 ADT: 91,692

PED/EMRGNCY ACCESS

Over: I-405

4.0 N JCT SR 520, King, WA

Built 2002 ADT: 186,135

N-E RAMP

Over: SE 8TH ST

1.7 N JCT I-90, King, WA

Built 2003 ADT: 19,658

NE 8TH ST

Over: I-405

2.7 N JCT I-90, King, WA

Built 2003 ADT: 162,591

NE 4TH ST

Over: I-405

2.4 N JCT I-90, King, WA

Built 2003 ADT: 144,832

RAMP

Over: COLLECTOR DISTRIBUTOR

2.4 N JCT I-90, King, WA

Built 2004 ADT: 16,919

SBCD RAMP

Over: COLLECTOR DISTRIBUTOR

2.4 N JCT I-90, King, WA

Built 2004 ADT: 16,919

NE 6TH ST

Over: 114TH AVE NE, I-405

2.6 N JCT I-90, King, WA

Built 2004 ADT: 72,416

GALER ST PED

Over: SR 99/AURORA AVE N

6.9 N JCT SR 509, King, WA

Built 2004 ADT: 50,006

SR 18

Over: SR 169,MAXWELL,TAYLOR CR

3.8 N JCT SR 516, King, WA

Built 2005 ADT: 21,491

SR 18

Over: SR 169,MAXWELL,TAYLOR CR

3.8 N JCT SR 516, King, WA

Built 2004 ADT: 21,491

SE 200TH

Over: SR 18

2.1 E JCT SR 169, King, WA

Built 2004 ADT: 30,286

S 317TH ST

Over: SB I-5, RAMP

2.0 N JCT SR 18, King, WA

Built 2006 ADT: 79,345

NE 128TH ST

Over: SB I-405

5.7 N JCT SR 520, King, WA

Built 2006 ADT: 63,798

NE 128TH ST

Over: NB I-405

5.7 N JCT SR 520, King, WA

Built 2006 ADT: 63,798

W-W RAMP

Over: SR 202 BNRR

7.7 E JCT SR 522, King, WA

Built 2007 ADT: 35,875

I-405

Over: I-90

JCT I-405, King, WA

Built 2008 ADT: 63,576

NE 10TH STREET

Over: I-405

2.9 N JCT I-90, King, WA

Built 2009 ADT: 162,591

I-90 W-N RAMP

Over: 4TH AVE AND SOUND TRANS

0.4 W JCT I-5, King, WA

Built 2010 ADT: 12,840

BENSON ROAD

Over: I-405

0.1 N JCT SR 515, King, WA

Built 2010 ADT: 91,263

SR 520 W-N RAMP

Over: SAMMAMISH PKWY/RIVER

4.9 E JCT I-405, King, WA

Built 2010 ADT: 38,940

SR 520 N-E RAMP

Over: W L SAMMAMISH PKWY/RIVER

4.9 E JCT I-405, King, WA

Built 2010 ADT: 38,940

NE 12 ST

Over: I-405

3.0 N JCT I-90, King, WA

Built 2011 ADT: 162,591

N-E RAMP

Over: CD RAMP AND TERRAIN

2.8 N JCT I-90, King, WA

Built 2011 ADT: 9,639

I-405-SR 520 NBCD

Over: I-405 N-E & N-W RAMPS

3.1 N JCT I-90, King, WA

Built 2011 ADT: 32,129

PEDESTRIAN XING

Over: US 2

23.8 E SNOHOMISH CO, King, WA

Built 2010 ADT: 4,584

SR 18 E-N RAMP

Over: I-5, SR 18, RAMPS

JCT I-5, King, WA

Built 2012 ADT: 66,885

SR 18 W-S RAMP

Over: I-5 & SR 18

JCT I-5, King, WA

Built 2012 ADT: 66,885

SR 520

Over: 108TH AVE NE

5.2 E JCT SR 513, King, WA

Built 2013 ADT: 15,083

BELLEVUE WAY NE

Over: SR 520

4.9 E JCT SR 513, King, WA

Built 2014 ADT: 52,112

PEDESTRIAN TRAIL

Over: N-E RAMP

4.1 E JCT SR 513, King, WA

Built 2014 ADT: 4,258

N-W RAMP

Over: I-405 N-E RAMP

7.9 N JCT SR 520, King, WA

Built 2015 ADT: 23,472

COLORADO AVE

Over: SR 99

3.9 N JCT SR 509, King, WA

Built 2013 ADT: 19,818

SR 99

Over: SR 99 NB, SR 99 NB/RAMP

5.5 N JCT SR 509, King, WA

Built 2015 ADT: 19,818

SR 99

Over: MERCER ST

5.7 N JCT SR 509, King, WA

Built 2015 ADT: 27,602

SR 167 SB HOV

Over: SR 18

2.3 E JCT I-5, King, WA

Built 2016 ADT: 57,729

N-N RAMP

Over: SR 515

6.9 N JCT SR 516, King, WA

Built 2017 ADT: 46,318

S-S RAMP

Over: SR 515

6.9 N JCT SR 516, King, WA

Built 2017 ADT: 46,318

SR 167 FLYOVER

Over: I-405 NB, SR 167 NB

6.5 N JCT SR 516, King, WA

Built 2018 ADT: 63,355

PEDESTRAIN TRAIL

Over: SR 520

0.3 E JCT SR 513, King, WA

Built 2023 ADT: 37,919

PEDESTRIAN TRAIL

Over: I-405 SOUTHBOUND

1.1 N JCT I-90, King, WA

Built 2023 ADT: 94,000

MAIN ST

Over: I-405

2.2 N JCT I-90, King, WA

Built 2023 ADT: 190,241

INTERURBAN TRAIL

Over: AURORA AVE/SR 99

0.6 N JCT SR 523, King, WA

Built 2009 ADT: 29,570

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

Related

Browse all → | Rankings →

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