Johnstonville RD over Susan River
FairLassen County, California · 0.3 MI N of US 395 · Structure no. 07C0027
- Built
- 1921
- 104 years old, rebuilt 1959
- Condition
- Fair
- inspected August 2023
- Type
- Slab
- Concrete Continuous
- Length
- 98 ft
- 3 main spans
- Daily traffic
- 600
- 1980 count
- Owner
- County
- County Highway Agency
About this bridge
Johnstonville RD over Susan River is a concrete continuous slab carrying Johnstonville RD over Susan River in Lassen County, California. It was built in 1921 and reconstructed in 1959, so it is 104 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 600 vehicles a day, roughly 10% of them trucks, projected to reach 981 by 2041. The structure is 98 ft (29.9 m) long and 34 ft wide. If it were closed, the detour would be 6.8 mi (11 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 | 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 | 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 Johnstonville RD over Susan River built?
It was built in 1921, making it 104 years old in 2025. It was reconstructed in 1959.
What condition is Johnstonville RD 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 2023.
How much traffic does Johnstonville RD over Susan River carry?
About 600 vehicles per day (1980 count), of which roughly 10% are trucks.
How long is Johnstonville RD over Susan River?
The structure is 98 ft (29.9 m) long with a longest span of 32 ft (9.8 m) and a deck 34 ft wide.
Who owns Johnstonville RD over Susan River?
It is owned by the County Highway Agency.