I-5 over Terrain
FairKing County, Washington · 4.5 N JCT SR 900 · Structure no. 0007816B0000000
- Built
- 1966
- 59 years old, rebuilt 1992
- Condition
- Fair
- inspected November 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 604 ft
- 6 main spans
- Daily traffic
- 122,487
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-5 over Terrain is a prestressed concrete continuous stringer/multi-beam or girder carrying I-5 over Terrain in King County, Washington. It was built in 1966 and reconstructed in 1992, 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.
It carries about 122,487 vehicles a day, roughly 7% of them trucks, projected to reach 176,868 by 2039. The structure is 604 ft (184.1 m) long and 73 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| 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 I-5 over Terrain built?
It was built in 1966, making it 59 years old in 2025. It was reconstructed in 1992.
What condition is I-5 over Terrain 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 November 2024.
How much traffic does I-5 over Terrain carry?
About 122,487 vehicles per day (2023 count), of which roughly 7% are trucks.
How long is I-5 over Terrain?
The structure is 604 ft (184.1 m) long with a longest span of 101 ft (30.8 m) and a deck 73 ft wide.
Who owns I-5 over Terrain?
It is owned by the State Highway Agency.