US 78 over Four Hole Swamp
Dorchester County, South Carolina · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US 78 over Four Hole Swamp in Dorchester County, South Carolina, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1948, making it 77 years old at the 2025 inventory.
- It carries about 9,900 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 4 of the 199 inventoried bridges in Dorchester County rated poor (2.0%); 4 (2.0%) are rated poor.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (33.14164, -80.34837)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 5 | Fair condition |
| Superstructure | 5 | Fair condition |
| Substructure | 4 | Poor condition |
Bridge details
| Structure | Concrete tee beam |
| Length | about 374 ft |
| Location | 3.8 Mi NW of Ridgeville |
| NBI structure number | 000000000001454 |
| Condition class | Poor |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Carolina department of transportation.
Busiest bridges in Dorchester 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 |
All bridges nearby: Dorchester County, SC bridge conditions · every bridge in Dorchester County · South Carolina bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.