S-21-918 over Polk Swamp
FairFlorence County, South Carolina · 3MI E Florence · Structure no. 000000000004121
- Built
- 1963
- 62 years old, rebuilt 2000
- Condition
- Fair
- inspected March 2023
- Type
- Slab
- Concrete
- Length
- 45 ft
- 3 main spans
- Daily traffic
- 1,750
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S-21-918 over Polk Swamp is a concrete slab carrying S-21-918 over Polk Swamp in Florence County, South Carolina. It was built in 1963 and reconstructed in 2000, so it is 62 years old, older 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 1,750 vehicles a day, roughly 2% of them trucks, projected to reach 1,050 by 2043. The structure is 45 ft (13.7 m) long and 28 ft wide. If it were closed, the detour would be 1.9 mi (3 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S-21-918 over Polk Swamp built?
It was built in 1963, making it 62 years old in 2025. It was reconstructed in 2000.
What condition is S-21-918 over Polk 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 March 2023.
How much traffic does S-21-918 over Polk Swamp carry?
About 1,750 vehicles per day (2023 count), of which roughly 2% are trucks.
How long is S-21-918 over Polk Swamp?
The structure is 45 ft (13.7 m) long with a longest span of 15 ft (4.6 m) and a deck 28 ft wide.
Who owns S-21-918 over Polk Swamp?
It is owned by the State Highway Agency.