SR 99 over Duwamish River

Fair Condition30 years old46,303 vehicles/day

Location

StateWashington
CountyKing
Location0.1 N Jct SR 509
CarriesSR 99
CrossesDuwamish River
Coordinates47.53794, -122.33500

Condition Ratings

Overall ConditionFair
Deck6 (Satisfactory)
Superstructure7 (Good)
Substructure6 (Satisfactory)
Channel/Waterway8 (Very Good)
Scour Critical8 — Stable, low risk

Physical Characteristics

MaterialSteel
DesignMovable - Bascule
Total Length2895.0 ft (882.4 m)
Max Span294.0 ft (89.6 m)
Deck Width57.7 ft (17.6 m)
Deck Area15530.2 sq m
Main Spans1
Year Built1996

Traffic

Avg Daily Traffic46,303 (2023)
Truck Traffic8%
Lanes On Bridge3
Lanes Under Bridge11

Inspection & Ownership

Last Inspection924
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceHistorical significance is not determined
Structure Number0014459A0000000

Nearby Bridges

SR 99 over Duwamish River 0.0 mi Fair SW Michigan ST over Wetland Mit. Channel 0.2 mi Good N-e Ramp over Occidental AVE S 0.4 mi Good SR 99 W-s Ramp over Bnrr City Street 0.5 mi Fair S-s Ramp over 1st AVE S 0.8 mi Fair Cloverdale ST over SR 509 0.8 mi Fair SR 509 over N-n Ramp 0.9 mi Fair SR 99 over Cloverdale ST 0.9 mi Fair Ramp To I-5 Nb/sb over City Sts Ramp & Rr 1.1 mi Fair I-5 S-w N-w Ramps over Airport Way 1.1 mi Good