River Road over Hillside
FairSonoma County, California · 1.7 MI West of Mirabel RD · Structure no. 20C0536
- Built
- 2003
- 22 years old
- Condition
- Fair
- inspected June 2023
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 78 ft
- 3 main spans
- Daily traffic
- 13,450
- 2015 count
- Owner
- County
- County Highway Agency
About this bridge
River Road over Hillside is a steel continuous stringer/multi-beam or girder carrying River Road over Hillside in Sonoma County, California. It was built in 2003, so it is 22 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.
It carries about 13,450 vehicles a day, roughly 2% of them trucks, projected to reach 20,610 by 2040. The structure is 78 ft (23.8 m) long and 14 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 | 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. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was River Road over Hillside built?
It was built in 2003, making it 22 years old in 2025.
What condition is River Road over Hillside 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 June 2023.
How much traffic does River Road over Hillside carry?
About 13,450 vehicles per day (2015 count), of which roughly 2% are trucks.
How long is River Road over Hillside?
The structure is 78 ft (23.8 m) long with a longest span of 27 ft (8.2 m) and a deck 14 ft wide.
Who owns River Road over Hillside?
It is owned by the County Highway Agency.