Interstate 8 over Knob Wash
GoodImperial County, California · 11-IMP-008-R89.90 · Structure no. 58 0108
- Built
- 1970
- 55 years old
- Condition
- Good
- inspected January 2025
- Type
- Culvert
- Concrete Continuous
- Length
- 36 ft
- 3 main spans
- Daily traffic
- 15,100
- 2022 count
- Owner
- State
- State Highway Agency
About this bridge
Interstate 8 over Knob Wash is a concrete continuous culvert carrying Interstate 8 over Knob Wash in Imperial County, California. It was built in 1970, so it is 55 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 15,100 vehicles a day, roughly 20% of them trucks, projected to reach 21,638 by 2044. The structure is 36 ft (11 m) long and 121 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 |
|---|---|---|
| Channel and channel protection | 7 Good | Some minor problems. |
| Culvert | 7 Good | Some minor problems. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was Interstate 8 over Knob Wash built?
It was built in 1970, making it 55 years old in 2025.
What condition is Interstate 8 over Knob Wash 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 Interstate 8 over Knob Wash carry?
About 15,100 vehicles per day (2022 count), of which roughly 20% are trucks.
How long is Interstate 8 over Knob Wash?
The structure is 36 ft (11 m) long with a longest span of 10 ft (3 m) and a deck 121 ft wide.
Who owns Interstate 8 over Knob Wash?
It is owned by the State Highway Agency.