U.S. Highway 101 over Big Lagoon
FairHumboldt County, California · 01-HUM-101-109.17 · Structure no. 04 0027
- Built
- 1958
- 67 years old
- Condition
- Fair
- inspected July 2024
- Type
- Tee Beam
- Concrete Continuous
- Length
- 443 ft
- 11 main spans
- Daily traffic
- 4,200
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
U.S. Highway 101 over Big Lagoon is a concrete continuous tee beam carrying U.S. Highway 101 over Big Lagoon in Humboldt County, California. It was built in 1958, so it is 67 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 4,200 vehicles a day, projected to reach 6,244 by 2042. The structure is 443 ft (135 m) long and 62 ft wide. If it were closed, the detour would be 78.9 mi (127 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 | 8 Very Good | No problems noted. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was U.S. Highway 101 over Big Lagoon built?
It was built in 1958, making it 67 years old in 2025.
What condition is U.S. Highway 101 over Big Lagoon 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 July 2024.
How much traffic does U.S. Highway 101 over Big Lagoon carry?
About 4,200 vehicles per day (2009 count).
How long is U.S. Highway 101 over Big Lagoon?
The structure is 443 ft (135 m) long with a longest span of 40 ft (12.2 m) and a deck 62 ft wide.
Who owns U.S. Highway 101 over Big Lagoon?
It is owned by the State Highway Agency.