Structure 27C0032 · Marin County, CA
Carries Nicasio Vly RD over Nicasio Drain #1, 12.4 Mi N Of HWY 101.
A culvert 24 ft across with 2 openings. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights, so those are drawn as typical for a culvert.
| State | California |
| County | Marin |
| Location | 12.4 Mi N Of HWY 101 |
| Carries | Nicasio Vly RD |
| Crosses | Nicasio Drain #1 |
| Coordinates | 38.07659, -122.70761 |
| Material | Concrete Continuous |
| Design | Culvert |
| Total Length | 23.6 ft (7.2 m) |
| Max Span | 11.8 ft (3.6 m) |
| Deck Area | 87.1 sq m |
| Main Spans | 2 |
| Year Built | 1968 |
| Avg Daily Traffic | 1,750 (1975) |
| Truck Traffic | 10% |
| Lanes On Bridge | 2 |
| Last Inspection | September 2024 |
| Inspection Frequency | Every 24 months |
| Owner | County Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 27C0032 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.