US Bridges

I-5 over S 259th Pl

Fair

King County, Washington · 5.6 N JCT SR 18 · Structure no. 0006186B0000000

Built
1960
65 years old, rebuilt 2002
Condition
Fair
inspected October 2024
Type
Slab
Concrete Continuous
Length
162 ft
3 main spans
Daily traffic
104,261
2023 count
Owner
State
State Highway Agency

About this bridge

I-5 over S 259th Pl is a concrete continuous slab carrying I-5 over S 259th Pl in King County, Washington. It was built in 1960 and reconstructed in 2002, so it is 65 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 104,261 vehicles a day, roughly 7% of them trucks, projected to reach 149,652 by 2039. The structure is 162 ft (49.4 m) long and 92 ft wide. If it were closed, the detour would be 1.2 mi (2 km).

Location

Open in Google Maps
CarriesI-5
CrossesS 259th Pl
Location5.6 N JCT SR 18
RouteInterstate 5
CountyKing County
StateWashington
Coordinates47.3695, -122.29381
Functional classUrban 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 inspectionOctober 2024
Inspection intervalevery 24 months
Operating statusOpen, no restriction
ScourBridge not over waterway
Structural evaluation6: Equal to present minimum criteria
Deck geometry6: Equal to present minimum criteria
Approach roadway alignment8: Equal to present desirable criteria
Operating rating54 US tons
Inventory rating32 US tons

Structure

Structure typeSlab
MaterialConcrete Continuous
DeckConcrete, cast-in-place
Main spans3
Design loadHS 20
Structure length162 ft (49.4 m)
Longest span61 ft (18.6 m)
Deck width92 ft (28.1 m)
Roadway width79 ft (24 m)
Vertical clearance over deckUnrestricted

Traffic and service

Average daily traffic104,261 (2023)
Projected traffic149,652 by 2039
Trucks7%
Lanes on structure5
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$6.5 million (2022 estimate)
NavigationNot applicable (no waterway)

Frequently asked questions

When was I-5 over S 259th Pl built?

It was built in 1960, making it 65 years old in 2025. It was reconstructed in 2002.

What condition is I-5 over S 259th Pl 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 October 2024.

How much traffic does I-5 over S 259th Pl carry?

About 104,261 vehicles per day (2023 count), of which roughly 7% are trucks.

How long is I-5 over S 259th Pl?

The structure is 162 ft (49.4 m) long with a longest span of 61 ft (18.6 m) and a deck 92 ft wide.

Who owns I-5 over S 259th Pl?

It is owned by the State Highway Agency.