US Bridges

I-90 over Denny Creek

Fair

King County, Washington · 19.8 E JCT SR 202 · Structure no. 0010200A0000000

Built
1981
44 years old
Condition
Fair
inspected August 2024
Type
Segmental Box Girder
Prestressed Concrete Continuous
Length
3,620 ft
20 main spans
Daily traffic
18,894
2023 count
Owner
State
State Highway Agency

About this bridge

I-90 over Denny Creek is a prestressed concrete continuous segmental box girder carrying I-90 over Denny Creek 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 18,894 vehicles a day, roughly 18% of them trucks, projected to reach 25,526 by 2039. The structure is 3,620 ft (1,103.4 m) long and 55 ft wide. If it were closed, the detour would be 8.1 mi (13 km).

Location

Open in Google Maps
CarriesI-90
CrossesDenny Creek
Location19.8 E JCT SR 202
RouteInterstate 90
CountyKing County
StateWashington
Coordinates47.41786, -121.4453
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.
Channel and channel protection8 Very GoodNo problems noted.
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
Waterway adequacy8: Equal to present desirable criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating47.5 US tons
Inventory rating45.3 US tons

Structure

Structure typeSegmental Box Girder
MaterialPrestressed Concrete Continuous
DeckConcrete, cast-in-place
Main spans20 (+1 approach)
Design loadHS 20 + Mod
Structure length3,620 ft (1,103.4 m)
Longest span188 ft (57.3 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
CrossesRelief for waterway
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 statusPossibly eligible for the National Register; requires further investigation
Work proposedRehabilitation because of general structure deterioration or inadequate strength
Estimated improvement cost$92.9 million (2022 estimate)
NavigationNo navigation control on waterway

Frequently asked questions

When was I-90 over Denny Creek built?

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

What condition is I-90 over Denny Creek 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 Denny Creek carry?

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

How long is I-90 over Denny Creek?

The structure is 3,620 ft (1,103.4 m) long with a longest span of 188 ft (57.3 m) and a deck 55 ft wide.

Who owns I-90 over Denny Creek?

It is owned by the State Highway Agency.