Bridge conditions in Williamsburg County, South Carolina
194 inventoried bridges · 12 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
The federal inventory lists 194 bridges in Williamsburg County: 77 rated good, 105 fair, and 12 poor.
- 12 of the 194 bridges in Williamsburg County, South Carolina, are rated in poor condition (6.2%) in the 2025 National Bridge Inventory, as of .
- 77 bridges (39.7%) are rated good and 105 (54.1%) fair.
- The median Williamsburg County bridge was built in 1973.
- The busiest poor-rated bridge is Sc 527 over Boggy Swamp (built 1943), carrying about 1,450 vehicles a day.
Good 39.7% · Fair 54.1% · Poor 6.2% of 194 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Sc 527 over Boggy Swamp | 1943 | 1,450 | Poor |
| S-45-33 over Mill Branch | 1972 | 1,400 | Poor |
| Sc 512 over Paisley Swamp (no. 2) | 1978 | 750 | Poor |
| S-45-38 over Cedar Swamp | 1976 | 350 | Poor |
| S-45-85 over Boggy Swamp | 1965 | 300 | Poor |
| S-45-454 over Br of Clapp Swamp | 1968 | 300 | Poor |
| S-45-259 over Clapp Swamp | 1960 | 275 | Poor |
| S-45-40 over Br of Muddy Ck (co Line) | 1963 | 275 | Poor |
| C-45-400 over Smiths Swamp | 1965 | 200 | Poor |
| L-964 Alvamarie Ln over BRANCH to Kingstree cana | 1961 | 200 | Poor |
| S-45-728 over Branch of Kingstree SW | 1984 | 175 | Poor |
| S-45-143 over Thorntree Swamp | 1973 | 150 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Sc 527 over S.c.l. RR | 1968 | 7,700 | Fair |
| Sc 41 over Black River | 2003 | 7,400 | Good |
| Sc 41 over Horsepen Creek | 1998 | 7,400 | Good |
| Sc 41 over Black Mingo Creek | 1942 | 6,700 | Fair |
| US 52 over Smith Swamp | 1952 | 6,200 | Good |
| US 52 over Black River Swamp | 2000 | 6,100 | Good |
| US 52 over Black River Swamp | 2000 | 6,100 | Fair |
| US 52 over Black River Overflow | 2000 | 6,100 | Fair |
| US 52 over Black River | 2000 | 6,100 | Good |
| S-45-186 over Br-kingstree Swp Canal | 1963 | 4,800 | Fair |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of South Carolina: South Carolina bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.