US Bridges

I-90 over SR 906 W-W Ramp

Poor

King County, Washington · 21.6 E JCT SR 202 · Structure no. 0008447A0000000

Built
1969
56 years old
Condition
Poor
inspected October 2023
Type
Stringer/Multi-beam or Girder
Prestressed Concrete Continuous
Length
206 ft
3 main spans
Daily traffic
17,601
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over SR 906 W-W Ramp is a prestressed concrete continuous stringer/multi-beam or girder carrying I-90 over SR 906 W-W Ramp in King County, Washington. It was built in 1969, so it is 56 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

It carries about 17,601 vehicles a day, roughly 18% of them trucks, projected to reach 23,753 by 2039. The structure is 206 ft (62.8 m) long and 140 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-90
CrossesSR 906 W-W Ramp
Location21.6 E JCT SR 202
RouteInterstate 90
CountyKing County
StateWashington
Coordinates47.42705, -121.41582
Functional classRural Principal Arterial - Interstate

Condition and inspection

Poor

The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.

ComponentRatingMeaning
Deck4 PoorAdvanced section loss, deterioration, spalling or scour.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure6 SatisfactoryStructural elements show some minor deterioration.
Last inspectionOctober 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry9: Superior to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating22.5 US tons
Inventory rating17.5 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length206 ft (62.8 m)
Longest span100 ft (30.5 m)
Deck width140 ft (42.7 m)
Roadway width136 ft (41.5 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,601 (2023)
Projected traffic23,753 by 2039
Trucks18%
Lanes on structure8
Traffic directionOne-way traffic
CarriesHighway
CrossesHighway
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 statusNot eligible for the National Register of Historic Places
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$10.4 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 over SR 906 W-W Ramp built?

It was built in 1969, making it 56 years old in 2025.

What condition is I-90 over SR 906 W-W Ramp in?

The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in October 2023.

How much traffic does I-90 over SR 906 W-W Ramp carry?

About 17,601 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is I-90 over SR 906 W-W Ramp?

The structure is 206 ft (62.8 m) long with a longest span of 100 ft (30.5 m) and a deck 140 ft wide.

Who owns I-90 over SR 906 W-W Ramp?

It is owned by the State Highway Agency.