State Route 121 over Arroyo Seco
Fair Condition103 years old19,000 vehicles/day
Location
| State | California |
| County | Sonoma |
| Location | 04-son-121-8.43 |
| Carries | State Route 121 |
| Crosses | Arroyo Seco |
| Coordinates | 38.24613, -122.43528 |
Condition Ratings
| Overall Condition | Fair |
| Deck | 5 (Fair) |
| Superstructure | 6 (Satisfactory) |
| Substructure | 5 (Fair) |
| Channel/Waterway | 6 (Satisfactory) |
| Scour Critical | 5 — Stable for scour |
Physical Characteristics
| Material | Concrete Continuous |
| Design | Tee Beam |
| Total Length | 82.0 ft (25 m) |
| Max Span | 40.0 ft (12.2 m) |
| Deck Width | 25.3 ft (7.7 m) |
| Deck Area | 192.5 sq m |
| Main Spans | 2 |
| Year Built | 1923 (reconstructed 1967) |
Traffic
| Avg Daily Traffic | 19,000 (2016) |
| Truck Traffic | 7% |
| Lanes On Bridge | 2 |
Inspection & Ownership
| Last Inspection | 924 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 20 0023 |