San Antonio RD over South San Antonio Creek
FairMarin County, California · 0.6 MI N of US 101 · Structure no. 27C0051
- Built
- 1917
- 108 years old
- Condition
- Fair
- inspected July 2024
- Type
- Girder and Floorbeam System
- Concrete
- Length
- 101 ft
- 2 main spans
- Daily traffic
- 200
- 1979 count
- Owner
- County
- County Highway Agency
About this bridge
San Antonio RD over South San Antonio Creek is a concrete girder and floorbeam system carrying San Antonio RD over South San Antonio Creek in Marin County, California. It was built in 1917, so it is 108 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 200 vehicles a day, roughly 2% of them trucks, projected to reach 220 by 2046. The structure is 101 ft (30.8 m) long and 24 ft wide. If it were closed, the detour would be 1.9 mi (3 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. |
| Channel and channel protection | 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 San Antonio RD over South San Antonio Creek built?
It was built in 1917, making it 108 years old in 2025.
What condition is San Antonio RD over South San Antonio Creek 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 San Antonio RD over South San Antonio Creek carry?
About 200 vehicles per day (1979 count), of which roughly 2% are trucks.
How long is San Antonio RD over South San Antonio Creek?
The structure is 101 ft (30.8 m) long with a longest span of 50 ft (15.1 m) and a deck 24 ft wide.
Who owns San Antonio RD over South San Antonio Creek?
It is owned by the County Highway Agency.