SR 520 over Portage Bay

Fair Condition63 years old18,129 vehicles/day

Location

StateWashington
CountyKing
Location0.3 E Jct I-5
CarriesSR 520
CrossesPortage Bay
Coordinates47.64275, -122.31767

Condition Ratings

Overall ConditionFair
Deck6 (Satisfactory)
Superstructure7 (Good)
Substructure5 (Fair)
Channel/Waterway8 (Very Good)
Scour Critical8 — Stable, low risk

Physical Characteristics

MaterialPrestressed Concrete
DesignStringer/Multi-beam
Total Length2840.9 ft (865.9 m)
Max Span100.1 ft (30.5 m)
Deck Width70.9 ft (21.6 m)
Deck Area18703.4 sq m
Main Spans29
Year Built1963

Traffic

Avg Daily Traffic18,129 (2023)
Truck Traffic3%
Lanes On Bridge4
Lanes Under Bridge2

Inspection & Ownership

Last Inspection324
Inspection FrequencyEvery 24 months
OwnerState Highway Agency
Historical SignificanceBridge is not eligible for the National Register
Structure Number0006819A0000000

Nearby Bridges