State Route 18 over Lower Bonnie Canyon
FairSan Bernardino County, California · 08-SBD-018-R14.78 · Structure no. 54 0923
- Built
- 1969
- 56 years old
- Condition
- Fair
- inspected October 2024
- Type
- Box Beam or Girders - Multiple
- Prestressed Concrete
- Length
- 161 ft
- 1 main span
- Daily traffic
- 16,800
- 2017 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 18 over Lower Bonnie Canyon is a prestressed concrete box beam or girders - multiple carrying State Route 18 over Lower Bonnie Canyon in San Bernardino County, California. It was built in 1969, 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 fair condition with a lowest component rating of 5 out of 9. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
It carries about 16,800 vehicles a day, roughly 10% of them trucks, projected to reach 20,000 by 2043. The structure is 161 ft (49.1 m) long and 63 ft wide. If it were closed, the detour would be 47.2 mi (76 km).
Location
Open in Google MapsCondition and inspection
The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| 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 18 over Lower Bonnie Canyon built?
It was built in 1969, making it 56 years old in 2025.
What condition is State Route 18 over Lower Bonnie Canyon in?
The National Bridge Inventory rates it in fair condition. The lowest-rated primary component is rated 5 or 6. Minor deterioration is present but the structure is sound. The last reported inspection was in October 2024.
How much traffic does State Route 18 over Lower Bonnie Canyon carry?
About 16,800 vehicles per day (2017 count), of which roughly 10% are trucks.
How long is State Route 18 over Lower Bonnie Canyon?
The structure is 161 ft (49.1 m) long with a longest span of 161 ft (49.1 m) and a deck 63 ft wide.
Who owns State Route 18 over Lower Bonnie Canyon?
It is owned by the State Highway Agency.