I-405 over N-W Ramp
FairKing County, Washington · 3.6 N JCT I-90 · Structure no. 0007596B0000000
- Built
- 1966
- 59 years old, rebuilt 1993
- Condition
- Fair
- inspected April 2024
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 207 ft
- 3 main spans
- Daily traffic
- 83,247
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-405 over N-W Ramp is a prestressed concrete continuous stringer/multi-beam or girder carrying I-405 over N-W Ramp in King County, Washington. It was built in 1966 and reconstructed in 1993, 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 83,247 vehicles a day, roughly 6% of them trucks, projected to reach 123,914 by 2039. The structure is 207 ft (63.1 m) long and 71 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-405 over N-W Ramp built?
It was built in 1966, making it 59 years old in 2025. It was reconstructed in 1993.
What condition is I-405 over N-W Ramp 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 April 2024.
How much traffic does I-405 over N-W Ramp carry?
About 83,247 vehicles per day (2023 count), of which roughly 6% are trucks.
How long is I-405 over N-W Ramp?
The structure is 207 ft (63.1 m) long with a longest span of 79 ft (24.1 m) and a deck 71 ft wide.
Who owns I-405 over N-W Ramp?
It is owned by the State Highway Agency.