US Bridges

I-90 over S Fk Snoqualmie River

Good

King County, Washington · 1.3 E JCT SR 202 · Structure no. 0009814B0000000

Built
1975
50 years old
Condition
Good
inspected July 2023
Type
Box Beam or Girders - Multiple
Concrete Continuous
Length
487 ft
4 main spans
Daily traffic
24,954
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over S Fk Snoqualmie River is a concrete continuous box beam or girders - multiple carrying I-90 over S Fk Snoqualmie River in King County, Washington. It was built in 1975, so it is 50 years old, older than the Washington average of 49.8 years.

The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

It carries about 24,954 vehicles a day, roughly 18% of them trucks, projected to reach 34,071 by 2039. The structure is 487 ft (148.4 m) long and 55 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesI-90
CrossesS Fk Snoqualmie River
Location1.3 E JCT SR 202
RouteInterstate 90
CountyKing County
StateWashington
Coordinates47.47427, -121.78047
Functional classRural Principal Arterial - Interstate

Condition and inspection

Good

All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure7 GoodSome minor problems.
Substructure7 GoodSome minor problems.
Channel and channel protection8 Very GoodNo problems noted.
Last inspectionJuly 2023
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations stable; action required to protect exposed foundations
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 US tons
Inventory rating57.9 US tons

Structure

Structure typeBox Beam or Girders - Multiple
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans4
Design loadHS 20 + Mod
Structure length487 ft (148.4 m)
Longest span142 ft (43.3 m)
Deck width55 ft (16.8 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic24,954 (2023)
Projected traffic34,071 by 2039
Trucks18%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesWaterway
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$12.5 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-90 over S Fk Snoqualmie River built?

It was built in 1975, making it 50 years old in 2025.

What condition is I-90 over S Fk Snoqualmie River in?

The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in July 2023.

How much traffic does I-90 over S Fk Snoqualmie River carry?

About 24,954 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is I-90 over S Fk Snoqualmie River?

The structure is 487 ft (148.4 m) long with a longest span of 142 ft (43.3 m) and a deck 55 ft wide.

Who owns I-90 over S Fk Snoqualmie River?

It is owned by the State Highway Agency.