Structure 8155F0000000 · King County, WA

12th AVE S over I-90

Carries 12th AVE S over I-90, 0.2 E Jct I-5.

Overall conditionFair

Set by its lowest-rated component: Deck and Superstructure and Substructure at 6 of 9.

How ratings work
Decksets the rating6/9 · Satisfactory
Superstructuresets the rating6/9 · Satisfactory
Substructuresets the rating6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
SEMI-TRUCK · 72 FT366 FT OVERALL50 FT0ELEVATION · LENGTHS TO SCALE
Deck 6/9Superstructure 6/9Substructure 6/9

366 ft end to end, longest span 126 ft: about 5 semi-trucks nose to tail. 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 multi-beam bridge.

Built196858 years old
Length366.1 ft111.6 m
Daily traffic18,400counted 2012
Last inspectedApril 2024every 24 months

Location

StateWashington
CountyKing
Location0.2 E Jct I-5
Carries12th AVE S
CrossesI-90
Coordinates47.59443, -122.31682

Physical Characteristics

MaterialSteel
DesignStringer/Multi-beam
Total Length366.1 ft (111.6 m)
Max Span126.0 ft (38.4 m)
Deck Width65.0 ft (19.8 m)
Deck Area2209.7 sq m
Main Spans4
Year Built1968

Traffic

Avg Daily Traffic18,400 (2012)
Truck Traffic1%
Lanes On Bridge4
Lanes Under Bridge17

Inspection & Ownership

Last InspectionApril 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number0008155F0000000

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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