RD 318 over Susan River
FairPosted for loadLassen County, California · 1.7 MI E/O RD 305 · Structure no. 07C0077
- Built
- 1975
- 50 years old
- Condition
- Fair
- inspected August 2024
- Type
- Stringer/Multi-beam or Girder
- Wood or Timber
- Length
- 59 ft
- 3 main spans
- Daily traffic
- 100
- 1979 count
- Owner
- County
- County Highway Agency
About this bridge
RD 318 over Susan River is a wood or timber stringer/multi-beam or girder carrying RD 318 over Susan River in Lassen County, California. It was built in 1975, so it is 50 years old, younger 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. Its operating status is: posted for load restriction.
It carries about 100 vehicles a day, roughly 6% of them trucks, projected to reach 137 by 2041. The structure is 59 ft (18 m) long and 25 ft wide. If it were closed, the detour would be 6.2 mi (10 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 | 7 Good | Some minor problems. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| 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 RD 318 over Susan River built?
It was built in 1975, making it 50 years old in 2025.
What condition is RD 318 over Susan River 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 RD 318 over Susan River carry?
About 100 vehicles per day (1979 count), of which roughly 6% are trucks.
How long is RD 318 over Susan River?
The structure is 59 ft (18 m) long with a longest span of 20 ft (6.1 m) and a deck 25 ft wide.
Who owns RD 318 over Susan River?
It is owned by the County Highway Agency.