SR 518 over Des Moines Way S
FairKing County, Washington · 0.6 E JCT SR 509 · Structure no. 0008644B0000000
- Built
- 1970
- 55 years old
- Condition
- Fair
- inspected March 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 233 ft
- 3 main spans
- Daily traffic
- 28,203
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
SR 518 over Des Moines Way S is a prestressed concrete continuous stringer/multi-beam or girder carrying SR 518 over Des Moines Way S in King County, Washington. It was built in 1970, so it is 55 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 28,203 vehicles a day, roughly 2% of them trucks, projected to reach 44,468 by 2039. The structure is 233 ft (71 m) long and 87 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was SR 518 over Des Moines Way S built?
It was built in 1970, making it 55 years old in 2025.
What condition is SR 518 over Des Moines Way S 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 March 2024.
How much traffic does SR 518 over Des Moines Way S carry?
About 28,203 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is SR 518 over Des Moines Way S?
The structure is 233 ft (71 m) long with a longest span of 112 ft (34.1 m) and a deck 87 ft wide.
Who owns SR 518 over Des Moines Way S?
It is owned by the State Highway Agency.