US 521 over Johnsons Swamp
FairWilliamsburg County, South Carolina · 1 MI NW of Andrews · Structure no. 000000000000583
- Built
- 1931
- 94 years old, rebuilt 1966
- Condition
- Fair
- inspected November 2024
- Type
- Tee Beam
- Concrete
- Length
- 200 ft
- 8 main spans
- Daily traffic
- 3,100
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
US 521 over Johnsons Swamp is a concrete tee beam carrying US 521 over Johnsons Swamp in Williamsburg County, South Carolina. It was built in 1931 and reconstructed in 1966, so it is 94 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 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 3,100 vehicles a day, roughly 16% of them trucks, projected to reach 5,394 by 2043. The structure is 200 ft (61 m) long and 45 ft wide. If it were closed, the detour would be 3.1 mi (5 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 | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Superstructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| Substructure | 5 Fair | All primary structural elements are sound but may have minor section loss, cracking, spalling or scour. |
| 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 US 521 over Johnsons Swamp built?
It was built in 1931, making it 94 years old in 2025. It was reconstructed in 1966.
What condition is US 521 over Johnsons 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 November 2024.
How much traffic does US 521 over Johnsons Swamp carry?
About 3,100 vehicles per day (2023 count), of which roughly 16% are trucks.
How long is US 521 over Johnsons Swamp?
The structure is 200 ft (61 m) long with a longest span of 25 ft (7.6 m) and a deck 45 ft wide.
Who owns US 521 over Johnsons Swamp?
It is owned by the State Highway Agency.