River Road over Hillside
FairSonoma County, California · 1.6 MI E Interctn SR 116 · Structure no. 20C0463
- Built
- 1979
- 46 years old
- Condition
- Fair
- inspected March 2024
- Type
- Stringer/Multi-beam or Girder
- Steel Continuous
- Length
- 59 ft
- 3 main spans
- Daily traffic
- 10,300
- 2009 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 1979, so it is 46 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 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 10,300 vehicles a day, roughly 3% of them trucks, projected to reach 11,123 by 2042. The structure is 59 ft (18 m) long and 9 ft wide. If it were closed, the detour would be 9.9 mi (16 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was River Road over Hillside built?
It was built in 1979, making it 46 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 March 2024.
How much traffic does River Road over Hillside carry?
About 10,300 vehicles per day (2009 count), of which roughly 3% are trucks.
How long is River Road over Hillside?
The structure is 59 ft (18 m) long with a longest span of 19 ft (5.8 m) and a deck 9 ft wide.
Who owns River Road over Hillside?
It is owned by the County Highway Agency.