Structure 1669A0000000 · King County, WA

SR 99 over N 46th ST

Carries SR 99 over N 46th ST, 9.0 N Jct SR 509.

Overall conditionFair

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

How ratings work
Deck7/9 · Good
Superstructuresets the rating6/9 · Satisfactory
Substructuresets the rating6/9 · Satisfactory
0 failed4 poor6 fair9 excellent

Elevation

Side view, colored by inspection rating
CAR · 15 FT92 FT OVERALL25 FT0ELEVATION · LENGTHS TO SCALE
Deck 7/9Superstructure 6/9 · sets the ratingSubstructure 6/9 · sets the rating

92 ft end to end, longest span 52 ft. Lengths and the car 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 tee-beam bridge.

Built193393 years old
Length91.9 ft28 m
Daily traffic21,386counted 2023
Last inspectedMarch 2024every 24 months

Location

StateWashington
CountyKing
Location9.0 N Jct SR 509
CarriesSR 99
CrossesN 46th ST
Coordinates47.66191, -122.34734

Physical Characteristics

MaterialConcrete Continuous
DesignTee Beam
Total Length91.9 ft (28 m)
Max Span51.8 ft (15.8 m)
Deck Width96.5 ft (29.4 m)
Deck Area823.2 sq m
Main Spans3
Year Built1933

Traffic

Avg Daily Traffic21,386 (2023)
Truck Traffic3%
Lanes On Bridge6
Lanes Under Bridge4

Inspection & Ownership

Last InspectionMarch 2024
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Scour CriticalNot applicable
Structure Number0001669A0000000

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.

Nearby Bridges