Interstate 505 over South Fork Willow Slough
FairYolo County, California · 03-YOL-505-10.33 · Structure no. 22 0116R
- Built
- 1959
- 66 years old, rebuilt 1980
- Condition
- Fair
- inspected May 2023
- Type
- Slab
- Concrete Continuous
- Length
- 84 ft
- 3 main spans
- Daily traffic
- 6,000
- 2010 count
- Owner
- State
- State Highway Agency
About this bridge
Interstate 505 over South Fork Willow Slough is a concrete continuous slab carrying Interstate 505 over South Fork Willow Slough in Yolo County, California. It was built in 1959 and reconstructed in 1980, so it is 66 years old, older than the California average of 54.8 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 6,000 vehicles a day, roughly 27% of them trucks, projected to reach 9,417 by 2041. The structure is 84 ft (25.7 m) long and 53 ft wide. If it were closed, the detour would be 0.6 mi (1 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. |
| 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 Interstate 505 over South Fork Willow Slough built?
It was built in 1959, making it 66 years old in 2025. It was reconstructed in 1980.
What condition is Interstate 505 over South Fork Willow Slough 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 May 2023.
How much traffic does Interstate 505 over South Fork Willow Slough carry?
About 6,000 vehicles per day (2010 count), of which roughly 27% are trucks.
How long is Interstate 505 over South Fork Willow Slough?
The structure is 84 ft (25.7 m) long with a longest span of 26 ft (7.9 m) and a deck 53 ft wide.
Who owns Interstate 505 over South Fork Willow Slough?
It is owned by the State Highway Agency.