I-405 over 9th Ave SE
GoodSnohomish County, Washington · 0.4 N JCT SR 527 · Structure no. 0008417B0000000
- Built
- 1968
- 57 years old, rebuilt 2001
- Condition
- Good
- inspected October 2023
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 189 ft
- 3 main spans
- Daily traffic
- 46,512
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
I-405 over 9th Ave SE is a prestressed concrete continuous stringer/multi-beam or girder carrying I-405 over 9th Ave SE 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 good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 46,512 vehicles a day, roughly 5% of them trucks, projected to reach 71,315 by 2039. The structure is 189 ft (57.6 m) long and 82 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| 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 9th Ave SE built?
It was built in 1968, making it 57 years old in 2025. It was reconstructed in 2001.
What condition is I-405 over 9th Ave SE in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in October 2023.
How much traffic does I-405 over 9th Ave SE carry?
About 46,512 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is I-405 over 9th Ave SE?
The structure is 189 ft (57.6 m) long with a longest span of 68 ft (20.7 m) and a deck 82 ft wide.
Who owns I-405 over 9th Ave SE?
It is owned by the State Highway Agency.