State Route 1 over Big River
FairMendocino County, California · 01-MEN-001-50.17 · Structure no. 10 0146
- Built
- 1961
- 64 years old
- Condition
- Fair
- inspected August 2024
- Type
- Box Beam or Girders - Multiple
- Concrete Continuous
- Length
- 509 ft
- 3 main spans
- Daily traffic
- 6,300
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 1 over Big River is a concrete continuous box beam or girders - multiple carrying State Route 1 over Big River in Mendocino County, California. It was built in 1961, so it is 64 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 6,300 vehicles a day, roughly 7% of them trucks, projected to reach 9,145 by 2042. The structure is 509 ft (155.1 m) long and 35 ft wide. If it were closed, the detour would be 88.9 mi (143 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 | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 1 over Big River built?
It was built in 1961, making it 64 years old in 2025.
What condition is State Route 1 over Big 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 State Route 1 over Big River carry?
About 6,300 vehicles per day (2009 count), of which roughly 7% are trucks.
How long is State Route 1 over Big River?
The structure is 509 ft (155.1 m) long with a longest span of 191 ft (58.2 m) and a deck 35 ft wide.
Who owns State Route 1 over Big River?
It is owned by the State Highway Agency.