Structure 85944000000000 · King County, WA

SW Spokane ST over W Waterway Of Duwamish

Carries SW Spokane ST over W Waterway Of Duwamish, 1200 SW Spokane ST.

Overall conditionFair

Set by its lowest-rated component: Superstructure at 5 of 9.

How ratings work
Deck6/9 · Satisfactory
Superstructuresets the rating5/9 · Fair
Substructure6/9 · Satisfactory
Channelnot part of overall7/9 · Good
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT836 FT OVERALL100 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 5/9 · sets the ratingSubstructure 6/9

836 ft end to end, longest span 440 ft: about 2.3 football fields. Lengths and the semi-truck on the deck are drawn to the same scale. Each part is colored by its latest inspection rating. The inventory records lengths but not heights or the layout of the shorter spans, so those are drawn as typical for a swing bridge (drawn closed).

Built199135 years old
Length836.0 ft254.8 m
Daily traffic11,500counted 2022
Last inspectedApril 2023every 24 months

Location

StateWashington
CountyKing
Location1200 SW Spokane ST
CarriesSW Spokane ST
CrossesW Waterway Of Duwamish
Coordinates47.57139, -122.35361

Physical Characteristics

MaterialPrestressed Concrete
DesignMovable - Swing
Total Length836.0 ft (254.8 m)
Max Span440.0 ft (134.1 m)
Deck Width50.9 ft (15.5 m)
Deck Area3949.4 sq m
Main Spans3
Year Built1991

Traffic

Avg Daily Traffic11,500 (2022)
Truck Traffic30%
Lanes On Bridge2

Inspection & Ownership

Last InspectionApril 2023
Inspection FrequencyEvery 24 months
OwnerCity/Municipal Highway Agency
Historical SignificanceHistorical significance is not determined
Scour Critical8 — Stable, low risk
Structure Number085944000000000

How Bridge Ratings Work

Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."

0Failed
1Imminent failure
2Critical
3Serious
4Poor
5Fair
6Satisfactory
7Good
8Very good
9Excellent
Good · lowest component 7–9
Fair · lowest component 5–6
Poor · lowest component 0–4

A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.

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