US Bridges

SR 99 over Tukwila Intl Blvd

FairPosted for load

King County, Washington · 1.8 N JCT I-5 · Structure no. 0007967D0000000

Built
1966
59 years old
Condition
Fair
inspected May 2024
Type
Stringer/Multi-beam or Girder
Prestressed Concrete
Length
236 ft
3 main spans
Daily traffic
17,276
2023 count
Owner
State
State Highway Agency

About this bridge

SR 99 over Tukwila Intl Blvd is a prestressed concrete stringer/multi-beam or girder carrying SR 99 over Tukwila Intl Blvd in King County, Washington. It was built in 1966, so it is 59 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. Its operating status is: posted for load restriction.

It carries about 17,276 vehicles a day, roughly 11% of them trucks, projected to reach 26,360 by 2039. The structure is 236 ft (71.9 m) long and 42 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

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CarriesSR 99
CrossesTukwila Intl Blvd
Location1.8 N JCT I-5
RouteState Highway 99
CountyKing County
StateWashington
Coordinates47.49778, -122.29497
Functional classUrban Principal Arterial - Other Freeway or Expressway

Condition and inspection

Fair

The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.

ComponentRatingMeaning
Deck7 GoodSome minor problems.
Superstructure6 SatisfactoryStructural elements show some minor deterioration.
Substructure7 GoodSome minor problems.
Last inspectionMay 2024
Inspection intervalevery 24 months
Operating statusPosted for load restriction
ScourBridge not over waterway
Structural evaluation3: Basically intolerable, requiring high priority of corrective action
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating21.8 US tons
Inventory rating16.8 US tons

Structure

Structure typeStringer/Multi-beam or Girder
MaterialPrestressed Concrete
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20 + Mod
Structure length236 ft (71.9 m)
Longest span124 ft (37.8 m)
Deck width42 ft (12.7 m)
Roadway width38 ft (11.6 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic17,276 (2023)
Projected traffic26,360 by 2039
Trucks11%
Lanes on structure2
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$4.7 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was SR 99 over Tukwila Intl Blvd built?

It was built in 1966, making it 59 years old in 2025.

What condition is SR 99 over Tukwila Intl Blvd 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 May 2024.

How much traffic does SR 99 over Tukwila Intl Blvd carry?

About 17,276 vehicles per day (2023 count), of which roughly 11% are trucks.

How long is SR 99 over Tukwila Intl Blvd?

The structure is 236 ft (71.9 m) long with a longest span of 124 ft (37.8 m) and a deck 42 ft wide.

Who owns SR 99 over Tukwila Intl Blvd?

It is owned by the State Highway Agency.