Structure 339 · Dorchester County, SC
Carries US 78/w 5th ST N over Great Cypress Swamp #6, 6.4 Mi NW Of Summerville.
A culvert 21 ft across with 2 openings. Lengths are drawn to scale; at this length a semi-truck would be a speck. Each part is colored by its latest inspection rating. The inventory records lengths but not heights, so those are drawn as typical for a culvert.
| State | South Carolina |
| County | Dorchester |
| Location | 6.4 Mi NW Of Summerville |
| Carries | US 78/w 5th ST N |
| Crosses | Great Cypress Swamp #6 |
| Coordinates | 33.08420, -80.26401 |
| Material | Concrete |
| Design | Culvert |
| Total Length | 21.3 ft (6.5 m) |
| Max Span | 9.8 ft (3 m) |
| Deck Width | 34.4 ft (10.5 m) |
| Deck Area | 68.2 sq m |
| Main Spans | 2 |
| Year Built | 1919 (reconstructed 1934) |
| Avg Daily Traffic | 7,800 (2023) |
| Truck Traffic | 10% |
| Lanes On Bridge | 2 |
| Last Inspection | April 2024 |
| Inspection Frequency | Every 12 months |
| Owner | State Highway Agency |
| Historical Significance | Historical significance is not determined |
| Scour Critical | 8 — Stable, low risk |
| Structure Number | 000000000000339 |
Inspectors rate each major part of a bridge (the deck you drive on, the superstructure of beams that holds it up, and the substructure of piers and abutments beneath) on a 0–9 scale. A bridge's overall condition is its lowest of those ratings, so one deteriorated component makes the whole bridge "poor."
A poor rating is not a closure. It means the bridge is flagged for priority repair or replacement; bridges judged unsafe are closed or posted with weight limits. The waterway (channel) rating is reported, but it does not count toward the overall classification.