S-21-721 over Grey Swamp #1
GoodFlorence County, South Carolina · 3 MI N Coward · Structure no. 000000000009172
- Built
- 1997
- 28 years old
- Condition
- Good
- inspected March 2024
- Type
- Slab
- Concrete
- Length
- 33 ft
- 1 main span
- Daily traffic
- 125
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S-21-721 over Grey Swamp #1 is a concrete slab carrying S-21-721 over Grey Swamp #1 in Florence County, South Carolina. It was built in 1997, so it is 28 years old, younger than the South Carolina average of 48 years.
The most recent inspection reported to the Federal Highway Administration rates it in good condition with a lowest component rating of 8 out of 9. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
It carries about 125 vehicles a day, roughly 5% of them trucks, projected to reach 160 by 2043. The structure is 33 ft (10.1 m) long and 36 ft wide. If it were closed, the detour would be 1.9 mi (3 km).
Location
Open in Google MapsCondition and inspection
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 8 Very Good | No problems noted. |
| Superstructure | 8 Very Good | No problems noted. |
| Substructure | 8 Very Good | No problems noted. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S-21-721 over Grey Swamp #1 built?
It was built in 1997, making it 28 years old in 2025.
What condition is S-21-721 over Grey Swamp #1 in?
The National Bridge Inventory rates it in good condition. All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted. The last reported inspection was in March 2024.
How much traffic does S-21-721 over Grey Swamp #1 carry?
About 125 vehicles per day (2023 count), of which roughly 5% are trucks.
How long is S-21-721 over Grey Swamp #1?
The structure is 33 ft (10.1 m) long with a longest span of 33 ft (10.1 m) and a deck 36 ft wide.
Who owns S-21-721 over Grey Swamp #1?
It is owned by the State Highway Agency.