S-31-99 over Back Swamp
GoodLee County, South Carolina · 1 MI E of Lynchburg · Structure no. 000000000002790
- Built
- 1958
- 67 years old
- Condition
- Good
- inspected July 2023
- Type
- Slab
- Concrete
- Length
- 45 ft
- 3 main spans
- Daily traffic
- 125
- 2023 count
- Owner
- State
- State Highway Agency
About this bridge
S-31-99 over Back Swamp is a concrete slab carrying S-31-99 over Back Swamp in Lee County, South Carolina. It was built in 1958, so it is 67 years old, older 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 7 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 7% of them trucks, projected to reach 160 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
All primary components (deck, superstructure, substructure, or culvert) are rated 7 or higher. No significant problems were noted.
| Component | Rating | Meaning |
|---|---|---|
| Deck | 7 Good | Some minor problems. |
| Superstructure | 7 Good | Some minor problems. |
| Substructure | 7 Good | Some minor problems. |
| Channel and channel protection | 8 Very Good | No problems noted. |
Structure
Traffic and service
Ownership and planned work
Frequently asked questions
When was S-31-99 over Back Swamp built?
It was built in 1958, making it 67 years old in 2025.
What condition is S-31-99 over Back Swamp 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 July 2023.
How much traffic does S-31-99 over Back Swamp carry?
About 125 vehicles per day (2023 count), of which roughly 7% are trucks.
How long is S-31-99 over Back 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-31-99 over Back Swamp?
It is owned by the State Highway Agency.