US Bridges

I-90 over Avalanche Path

Fair

King County, Washington · 20.5 E JCT SR 202 · Structure no. 0008844A0000000

Built
1971
54 years old
Condition
Fair
inspected August 2024
Type
Stringer/Multi-beam or Girder
Steel Continuous
Length
700 ft
2 main spans
Daily traffic
18,894
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over Avalanche Path is a steel continuous stringer/multi-beam or girder carrying I-90 over Avalanche Path in King County, Washington. It was built in 1971, so it is 54 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 18,894 vehicles a day, roughly 18% of them trucks, projected to reach 25,526 by 2039. The structure is 700 ft (213.4 m) long and 55 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

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CarriesI-90
CrossesAvalanche Path
Location20.5 E JCT SR 202
RouteInterstate 90
CountyKing County
StateWashington
Coordinates47.42466, -121.43507
Functional classRural 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.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionAugust 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourFoundations on dry land well above flood water elevations
Structural evaluation6: Equal to present minimum criteria
Deck geometry5: Somewhat better than minimum adequacy to tolerate being left in place as is
Approach roadway alignment8: Equal to present desirable criteria
Operating rating63.9 US tons
Inventory rating39 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialSteel Continuous
DeckConcrete, cast-in-place
Main spans2
Design loadHS 20 + Mod
Structure length700 ft (213.4 m)
Longest span350 ft (106.7 m)
Deck width55 ft (16.8 m)
Roadway width52 ft (15.8 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic18,894 (2023)
Projected traffic25,526 by 2039
Trucks18%
Lanes on structure3
Traffic directionOne-way traffic
CarriesHighway
CrossesOther
Detour if closed8.1 mi (13 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$18.6 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-90 over Avalanche Path built?

It was built in 1971, making it 54 years old in 2025.

What condition is I-90 over Avalanche Path 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 August 2024.

How much traffic does I-90 over Avalanche Path carry?

About 18,894 vehicles per day (2023 count), of which roughly 18% are trucks.

How long is I-90 over Avalanche Path?

The structure is 700 ft (213.4 m) long with a longest span of 350 ft (106.7 m) and a deck 55 ft wide.

Who owns I-90 over Avalanche Path?

It is owned by the State Highway Agency.