US Bridges

I-90 Ramp over W Lake Sammamish Pkwy

Fair

King County, Washington · 3.7 E JCT I-405 · Structure no. 0009133C0000000

Built
1972
53 years old, rebuilt 2009
Condition
Fair
inspected November 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
363 ft
3 main spans
Daily traffic
2,956
2019 count
Owner
State
State Highway Agency

About this bridge

I-90 Ramp over W Lake Sammamish Pkwy is a steel continuous stringer/multi-beam or girder carrying I-90 Ramp over W Lake Sammamish Pkwy in King County, Washington. It was built in 1972 and reconstructed in 2009, so it is 53 years old, older 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 2,956 vehicles a day, roughly 5% of them trucks, projected to reach 4,173 by 2039. The structure is 363 ft (110.6 m) long and 30 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-90 Ramp
CrossesW Lake Sammamish Pkwy
Location3.7 E JCT I-405
RouteInterstate 90
CountyKing County
StateWashington
Coordinates47.56497, -122.09969
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
Deck6 SatisfactoryStructural elements show some minor deterioration.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Last inspectionNovember 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation7: Better than present minimum criteria
Deck geometry8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating61 US tons
Inventory rating37 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length363 ft (110.6 m)
Longest span136 ft (41.5 m)
Deck width30 ft (9 m)
Roadway width26 ft (7.9 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic2,956 (2019)
Projected traffic4,173 by 2039
Trucks5%
Lanes on structure1
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
Detour if closed1.2 mi (2 km)
TollOn a free road
National Highway SystemYes

Ownership and planned work

OwnerState Highway Agency
Maintained byState Highway Agency
Historic statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$5.5 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 Ramp over W Lake Sammamish Pkwy built?

It was built in 1972, making it 53 years old in 2025. It was reconstructed in 2009.

What condition is I-90 Ramp over W Lake Sammamish Pkwy 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 November 2024.

How much traffic does I-90 Ramp over W Lake Sammamish Pkwy carry?

About 2,956 vehicles per day (2019 count), of which roughly 5% are trucks.

How long is I-90 Ramp over W Lake Sammamish Pkwy?

The structure is 363 ft (110.6 m) long with a longest span of 136 ft (41.5 m) and a deck 30 ft wide.

Who owns I-90 Ramp over W Lake Sammamish Pkwy?

It is owned by the State Highway Agency.