State Route 299 over Mad River
Poor Condition61 years old4,775 vehicles/day
Location
| State | California |
| County | Humboldt |
| Location | 01-hum-299-r1.56 |
| Carries | State Route 299 |
| Crosses | Mad River |
| Coordinates | 40.91034, -124.06274 |
Condition Ratings
| Overall Condition | Poor |
| Deck | 4 (Poor) |
| Superstructure | 7 (Good) |
| Substructure | 7 (Good) |
| Channel/Waterway | 6 (Satisfactory) |
| Scour Critical | 5 — Stable for scour |
Physical Characteristics
| Material | Steel Continuous |
| Design | Stringer/Multi-beam |
| Total Length | 518.0 ft (157.9 m) |
| Max Span | 149.9 ft (45.7 m) |
| Deck Width | 38.4 ft (11.7 m) |
| Deck Area | 1847.4 sq m |
| Main Spans | 2 |
| Year Built | 1965 |
Traffic
| Avg Daily Traffic | 4,775 (2010) |
| Truck Traffic | 14% |
| Lanes On Bridge | 2 |
| Lanes Under Bridge | 2 |
Inspection & Ownership
| Last Inspection | November 2023 |
| Inspection Frequency | Every 24 months |
| Owner | State Highway Agency |
| Historical Significance | Bridge is not eligible for the National Register |
| Structure Number | 04 0036L |