Interstate 505 over Union School Slough
FairYolo County, California · 03-YOL-505-5.71 · Structure no. 22 0114L
- Built
- 1959
- 66 years old
- Condition
- Fair
- inspected May 2023
- Type
- Slab
- Concrete Continuous
- Length
- 63 ft
- 3 main spans
- Daily traffic
- 12,000
- 2010 count
- Owner
- State
- State Highway Agency
About this bridge
Interstate 505 over Union School Slough is a concrete continuous slab carrying Interstate 505 over Union School Slough in Yolo County, California. It was built in 1959, 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 12,000 vehicles a day, roughly 27% of them trucks, projected to reach 21,353 by 2041. The structure is 63 ft (19.1 m) long and 45 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. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Interstate 505 over Union School Slough built?
It was built in 1959, making it 66 years old in 2025.
What condition is Interstate 505 over Union School 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 Union School Slough carry?
About 12,000 vehicles per day (2010 count), of which roughly 27% are trucks.
How long is Interstate 505 over Union School Slough?
The structure is 63 ft (19.1 m) long with a longest span of 20 ft (6.1 m) and a deck 45 ft wide.
Who owns Interstate 505 over Union School Slough?
It is owned by the State Highway Agency.