US Bridges

East Marginal Way over Duwamish River

Fair

King County, Washington · 0.14 N JCT Interurban Ave · Structure no. 081102000000000

Built
1989
36 years old
Condition
Fair
inspected April 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
272 ft
1 main span
Daily traffic
13,500
2022 count
Owner
City
City or Municipal Highway Agency

About this bridge

East Marginal Way over Duwamish River is a prestressed concrete continuous stringer/multi-beam or girder carrying East Marginal Way over Duwamish River in King County, Washington. It was built in 1989, so it is 36 years old, younger than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in fair condition with a lowest component rating of 6 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

It carries about 13,500 vehicles a day, roughly 12% of them trucks, projected to reach 14,500 by 2042. The structure is 272 ft (82.9 m) long and 61 ft wide. If it were closed, the detour would be 6.2 mi (10 km).

Location

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CarriesEast Marginal Way
CrossesDuwamish River
Location0.14 N JCT Interurban Ave
RouteCity Street 90705
CountyKing County
StateWashington
Coordinates47.50022, -122.28813
Functional classUrban Other Principal Arterial

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionApril 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourUnknown foundation; not evaluated for scour
Structural evaluation7: Better than present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating75.4 US tons
Inventory rating45 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans1 (+2 approach)
Design loadH 20
Structure length272 ft (82.9 m)
Longest span176 ft (53.6 m)
Deck width61 ft (18.7 m)
Roadway width48 ft (14.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic13,500 (2022)
Projected traffic14,500 by 2042
Trucks12%
Lanes on structure3
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesWaterway
Detour if closed6.2 mi (10 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerCity or Municipal Highway Agency
Maintained byCity or Municipal Highway Agency
Historic statusHistorical significance not determinable at this time
Work proposedReplacement because of substandard load-carrying capacity or roadway geometry
Estimated improvement cost$13.4 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was East Marginal Way over Duwamish River built?

It was built in 1989, making it 36 years old in 2025.

What condition is East Marginal Way over Duwamish River in?

The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in April 2023.

How much traffic does East Marginal Way over Duwamish River carry?

About 13,500 vehicles per day (2022 count), of which roughly 12% are trucks.

How long is East Marginal Way over Duwamish River?

The structure is 272 ft (82.9 m) long with a longest span of 176 ft (53.6 m) and a deck 61 ft wide.

Who owns East Marginal Way over Duwamish River?

It is owned by the City or Municipal Highway Agency.