U.S. Highway 101 over Sierra Ave
FairSonoma County, California · 04-SON-101-12.00-COTI · Structure no. 20 0167
- Built
- 1956
- 69 years old, rebuilt 2011
- Condition
- Fair
- inspected April 2024
- Type
- Tee Beam
- Concrete Continuous
- Length
- 121 ft
- 3 main spans
- Daily traffic
- 86,000
- 2016 count
- Owner
- State
- State Highway Agency
About this bridge
U.S. Highway 101 over Sierra Ave is a concrete continuous tee beam carrying U.S. Highway 101 over Sierra Ave in Sonoma County, California. It was built in 1956 and reconstructed in 2011, so it is 69 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 86,000 vehicles a day, roughly 6% of them trucks, projected to reach 147,724 by 2046. The structure is 121 ft (37 m) long and 114 ft wide. If it were closed, the detour would be 5 mi (8 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 | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was U.S. Highway 101 over Sierra Ave built?
It was built in 1956, making it 69 years old in 2025. It was reconstructed in 2011.
What condition is U.S. Highway 101 over Sierra Ave 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 April 2024.
How much traffic does U.S. Highway 101 over Sierra Ave carry?
About 86,000 vehicles per day (2016 count), of which roughly 6% are trucks.
How long is U.S. Highway 101 over Sierra Ave?
The structure is 121 ft (37 m) long with a longest span of 46 ft (14 m) and a deck 114 ft wide.
Who owns U.S. Highway 101 over Sierra Ave?
It is owned by the State Highway Agency.