Bridge conditions in Dorchester County, South Carolina
199 inventoried bridges · 4 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
4 of the 199 bridges the federal inventory lists in Dorchester County are rated poor; the rest split 57 good and 138 fair.
- 4 of the 199 bridges in Dorchester County, South Carolina, are rated in poor condition (2.0%) in the 2025 National Bridge Inventory, as of .
- 57 bridges (28.6%) are rated good and 138 (69.3%) fair.
- The median Dorchester County bridge was built in 1972.
- The busiest poor-rated bridge is US 17 Alt over Ashley River (built 1971), carrying about 19,800 vehicles a day.
Good 28.6% · Fair 69.3% · Poor 2.0% of 199 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 |
|---|---|---|---|
| US 17 Alt over Ashley River | 1971 | 19,800 | Poor |
| US 78 over Four Hole Swamp | 1948 | 9,900 | Poor |
| US 15 over Edisto River | 1928 | 2,700 | Poor |
| S-18-19/wire Rd over Indian Fields Swamp | 1960 | 1,000 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-95 over Polk Swamp | 1974 | 50,100 | Fair |
| Sc 642 over Eagle Creek | 1956 | 40,300 | Fair |
| Sc 642 over Dorchester Creek | 1956 | 37,200 | Fair |
| Sc 165 over Julia Creek | 1997 | 34,500 | Fair |
| Sc 165 over RR NS & S-10-65 | 1998 | 34,500 | Good |
| S-18-230/ladson Rd over Chandler Bridge Creek | 2004 | 30,600 | Good |
| Sc 165 over Saw Mill Creek | 1989 | 30,600 | Good |
| Sc 165 over Ashley River Overflow | 2016 | 28,700 | Good |
| Sc 165 over Ashley River | 2016 | 28,700 | Good |
| S-18-199 over Br of Dorchester Creek | 1999 | 27,400 | 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.