I-5 over Terrain
FairKing County, Washington · 5.6 N JCT SR 900 · Structure no. 0007741C0000000
- Built
- 1966
- 59 years old, rebuilt 1992
- Condition
- Fair
- inspected November 2024
- Type
- Slab
- Concrete Continuous
- Length
- 872 ft
- 21 main spans
- Daily traffic
- 96,609
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-5 over Terrain is a concrete continuous slab 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 96,609 vehicles a day, roughly 7% of them trucks, projected to reach 139,501 by 2039. The structure is 872 ft (265.8 m) long and 61 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 | 7 Good | Some minor problems. |
| 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 96,609 vehicles per day (2023 count), of which roughly 7% are trucks.
How long is I-5 over Terrain?
The structure is 872 ft (265.8 m) long with a longest span of 45 ft (13.7 m) and a deck 61 ft wide.
Who owns I-5 over Terrain?
It is owned by the State Highway Agency.