Forty Mile RD over Best Slough
FairYuba County, California · 0.3 MI S Plumas Arboga RD · Structure no. 16C0020
- Built
- 1948
- 77 years old
- Condition
- Fair
- inspected August 2024
- Type
- Slab
- Concrete Continuous
- Length
- 62 ft
- 3 main spans
- Daily traffic
- 1,630
- 2013 count
- Owner
- County
- County Highway Agency
About this bridge
Forty Mile RD over Best Slough is a concrete continuous slab carrying Forty Mile RD over Best Slough in Yuba County, California. It was built in 1948, so it is 77 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 5 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 1,630 vehicles a day, roughly 10% of them trucks, projected to reach 3,348 by 2046. The structure is 62 ft (18.9 m) long and 30 ft wide. If it were closed, the detour would be 11.2 mi (18 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Channel and channel protection | 4 Poor | Advanced section loss, deterioration, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Forty Mile RD over Best Slough built?
It was built in 1948, making it 77 years old in 2025.
What condition is Forty Mile RD over Best 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 August 2024.
How much traffic does Forty Mile RD over Best Slough carry?
About 1,630 vehicles per day (2013 count), of which roughly 10% are trucks.
How long is Forty Mile RD over Best Slough?
The structure is 62 ft (18.9 m) long with a longest span of 20 ft (6.1 m) and a deck 30 ft wide.
Who owns Forty Mile RD over Best Slough?
It is owned by the County Highway Agency.