US Bridges

I-90 over East Channel-Lk Wash

Fair

King County, Washington · 5.9 E JCT I-5 · Structure no. 0011490A0000000

Built
1981
44 years old
Condition
Fair
inspected September 2024
Type
Box Beam or Girders - Single or Spread
Steel Continuous
Length
2,224 ft
9 main spans
Daily traffic
66,975
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over East Channel-Lk Wash is a steel continuous box beam or girders - single or spread carrying I-90 over East Channel-Lk Wash in King County, Washington. It was built in 1981, so it is 44 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 66,975 vehicles a day, roughly 3% of them trucks, projected to reach 105,549 by 2039. The structure is 2,224 ft (677.9 m) long and 92 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-90
CrossesEast Channel-Lk Wash
Location5.9 E JCT I-5
RouteInterstate 90
CountyKing County
StateWashington
Coordinates47.57822, -122.20471
Functional classUrban Principal Arterial - Interstate

Condition and inspection

Fair

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

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionSeptember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; scour above top of footing
Structural evaluation6: Equal to present minimum criteria
Deck geometry4: Meets minimum tolerable limits to be left in place as is
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating82 US tons
Inventory rating48.9 US tons

Structure

Structure typeBox Beam or Girders - Single or Spread
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans9
Design loadHS 20 + Mod
Structure length2,224 ft (677.9 m)
Longest span300 ft (91.4 m)
Deck width92 ft (28 m)
Roadway width80 ft (24.4 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic66,975 (2023)
Projected traffic105,549 by 2039
Trucks3%
Lanes on structure6
Traffic directionTwo-way traffic
CarriesHighway and pedestrian
CrossesHighway and waterway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes
Strategic Highway NetworkInterstate STRAHNET route

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusEligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$86.6 million (2022 estimate)
NavigationNavigation control on waterway (bridge permit required)

Frequently asked questions

When was I-90 over East Channel-Lk Wash built?

It was built in 1981, making it 44 years old in 2025.

What condition is I-90 over East Channel-Lk Wash 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 September 2024.

How much traffic does I-90 over East Channel-Lk Wash carry?

About 66,975 vehicles per day (2023 count), of which roughly 3% are trucks.

How long is I-90 over East Channel-Lk Wash?

The structure is 2,224 ft (677.9 m) long with a longest span of 300 ft (91.4 m) and a deck 92 ft wide.

Who owns I-90 over East Channel-Lk Wash?

It is owned by the State Highway Agency.