State Route 299 over North Fork Mad River
GoodHumboldt County, California · 01-HUM-299-R11.02 · Structure no. 04 0194
- Built
- 1969
- 56 years old, rebuilt 1994
- Condition
- Good
- inspected January 2025
- Type
- Stringer/Multi-beam or Girder
- Prestressed Concrete Continuous
- Length
- 422 ft
- 4 main spans
- Daily traffic
- 3,500
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 299 over North Fork Mad River is a prestressed concrete continuous stringer/multi-beam or girder carrying State Route 299 over North Fork Mad River in Humboldt County, California. It was built in 1969 and reconstructed in 1994, so it is 56 years old, older than the California average of 54.8 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 7 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 3,500 vehicles a day, roughly 10% of them trucks, projected to reach 4,991 by 2045. The structure is 422 ft (128.6 m) long and 44 ft wide. If it were closed, the detour would be 1.2 mi (2 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 299 over North Fork Mad River built?
It was built in 1969, making it 56 years old in 2025. It was reconstructed in 1994.
What condition is State Route 299 over North Fork Mad River in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in January 2025.
How much traffic does State Route 299 over North Fork Mad River carry?
About 3,500 vehicles per day (2009 count), of which roughly 10% are trucks.
How long is State Route 299 over North Fork Mad River?
The structure is 422 ft (128.6 m) long with a longest span of 106 ft (32.2 m) and a deck 44 ft wide.
Who owns State Route 299 over North Fork Mad River?
It is owned by the State Highway Agency.