State Route 99 SB over Duck Slough Overflow
FairMerced County, California · 10-MER-099-9.86 · Structure no. 39 0244L
- Built
- 2015
- 10 years old
- Condition
- Fair
- inspected April 2024
- Type
- Slab
- Concrete Continuous
- Length
- 161 ft
- 4 main spans
- Daily traffic
- 19,500
- 2009 count
- Owner
- State
- State Highway Agency
About this bridge
State Route 99 SB over Duck Slough Overflow is a concrete continuous slab carrying State Route 99 SB over Duck Slough Overflow in Merced County, California. It was built in 2015, so it is 10 years old, younger 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 6 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 19,500 vehicles a day, roughly 20% of them trucks, projected to reach 28,836 by 2044. The structure is 161 ft (49 m) long and 59 ft wide. If it were closed, the detour would be 8.7 mi (14 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Superstructure | 6 Satisfactory | Structural elements show some minor deterioration. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 9 Excellent | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was State Route 99 SB over Duck Slough Overflow built?
It was built in 2015, making it 10 years old in 2025.
What condition is State Route 99 SB over Duck Slough Overflow 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 April 2024.
How much traffic does State Route 99 SB over Duck Slough Overflow carry?
About 19,500 vehicles per day (2009 count), of which roughly 20% are trucks.
How long is State Route 99 SB over Duck Slough Overflow?
The structure is 161 ft (49 m) long with a longest span of 40 ft (12.2 m) and a deck 59 ft wide.
Who owns State Route 99 SB over Duck Slough Overflow?
It is owned by the State Highway Agency.