42nd Ave So over Duwamish River
PoorPosted for loadKing County, Washington · 0.04 MI E of SR-599 · Structure no. 081097000000000
- Built
- 1949
- 76 years old
- Condition
- Poor
- inspected April 2023
- Type
- Truss - Thru
- Steel
- Length
- 284 ft
- 1 main span
- Daily traffic
- 3,185
- 2022 count
- Owner
- City
- City or Municipal Highway Agency
About this bridge
42nd Ave So over Duwamish River is a steel truss - thru carrying 42nd Ave So over Duwamish River in King County, Washington. It was built in 1949, so it is 76 years old, older than the Washington average of 49.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in poor condition with a lowest component rating of 4 out of 9. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. Its operating status is: posted for load restriction.
It carries about 3,185 vehicles a day, roughly 30% of them trucks, projected to reach 12,000 by 2040. The structure is 284 ft (86.6 m) long and 30 ft wide. If it were closed, the detour would be 1.9 mi (3 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
| Channel and channel protection | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was 42nd Ave So over Duwamish River built?
It was built in 1949, making it 76 years old in 2025.
What condition is 42nd Ave So over Duwamish River in?
The National Bridge Inventory rates it in poor condition. The lowest-rated primary component is rated 4 or below, indicating advanced deterioration. Poor does not mean unsafe; such bridges are inspected more often and may carry load restrictions. The last reported inspection was in April 2023.
How much traffic does 42nd Ave So over Duwamish River carry?
About 3,185 vehicles per day (2022 count), of which roughly 30% are trucks.
How long is 42nd Ave So over Duwamish River?
The structure is 284 ft (86.6 m) long with a longest span of 220 ft (67.1 m) and a deck 30 ft wide.
Who owns 42nd Ave So over Duwamish River?
It is owned by the City or Municipal Highway Agency.