SE 231st ST over SR 18
FairKing County, Washington · 4.3 E JCT SR 516 · Structure no. 0009289A0000000
- Built
- 1972
- 53 years old, rebuilt 2001
- Condition
- Fair
- inspected October 2023
- Type
- Box Beam or Girders - Multiple
- Prestressed Concrete Continuous
- Length
- 274 ft
- 2 main spans
- Daily traffic
- 17,714
- 2010 count
- Owner
- State
- State Highway Agency
About this bridge
SE 231st ST over SR 18 is a prestressed concrete continuous box beam or girders - multiple carrying SE 231st ST over SR 18 in King County, Washington. It was built in 1972 and reconstructed in 2001, so it is 53 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 17,714 vehicles a day, roughly 1% of them trucks, projected to reach 29,228 by 2036. The structure is 274 ft (83.5 m) long and 78 ft wide. If it were closed, the detour would be 1.9 mi (3 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 | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was SE 231st ST over SR 18 built?
It was built in 1972, making it 53 years old in 2025. It was reconstructed in 2001.
What condition is SE 231st ST over SR 18 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 2023.
How much traffic does SE 231st ST over SR 18 carry?
About 17,714 vehicles per day (2010 count), of which roughly 1% are trucks.
How long is SE 231st ST over SR 18?
The structure is 274 ft (83.5 m) long with a longest span of 140 ft (42.7 m) and a deck 78 ft wide.
Who owns SE 231st ST over SR 18?
It is owned by the State Highway Agency.