I-405 over Damson RD
FairSnohomish County, Washington · 2.2 N JCT SR 527 · Structure no. 0008417D0000000
- Built
- 1968
- 57 years old, rebuilt 2001
- Condition
- Fair
- inspected August 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 187 ft
- 3 main spans
- Daily traffic
- 61,143
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-405 over Damson RD is a prestressed concrete continuous stringer/multi-beam or girder carrying I-405 over Damson RD in Snohomish County, Washington. It was built in 1968 and reconstructed in 2001, so it is 57 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 61,143 vehicles a day, roughly 5% of them trucks, projected to reach 93,782 by 2039. The structure is 187 ft (57 m) long and 70 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-405 over Damson RD built?
It was built in 1968, making it 57 years old in 2025. It was reconstructed in 2001.
What condition is I-405 over Damson RD 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 August 2023.
How much traffic does I-405 over Damson RD carry?
About 61,143 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is I-405 over Damson RD?
The structure is 187 ft (57 m) long with a longest span of 71 ft (21.6 m) and a deck 70 ft wide.
Who owns I-405 over Damson RD?
It is owned by the State Highway Agency.