S-21-146 over Deep Swamp
FairFlorence County, South Carolina · 4MI SW Timmonsville · Structure no. 000000000007455
- Built
- 1981
- 44 years old
- Condition
- Fair
- inspected April 2023
- Type
- Slab
- Concrete
- Length
- 60 ft
- 4 main spans
- Daily traffic
- 250
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S-21-146 over Deep Swamp is a concrete slab carrying S-21-146 over Deep Swamp in Florence County, South Carolina. It was built in 1981, so it is 44 years old, younger than the South Carolina average of 48 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 250 vehicles a day, roughly 5% of them trucks, projected to reach 320 by 2043. The structure is 60 ft (18.3 m) long and 33 ft wide. If it were closed, the detour would be 1.2 mi (2 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 | 6 Satisfactory | Structural elements show some minor deterioration. |
| Channel and channel protection | 6 Satisfactory | Structural elements show some minor deterioration. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S-21-146 over Deep Swamp built?
It was built in 1981, making it 44 years old in 2025.
What condition is S-21-146 over Deep Swamp 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 2023.
How much traffic does S-21-146 over Deep Swamp carry?
About 250 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is S-21-146 over Deep Swamp?
The structure is 60 ft (18.3 m) long with a longest span of 15 ft (4.6 m) and a deck 33 ft wide.
Who owns S-21-146 over Deep Swamp?
It is owned by the State Highway Agency.