S-20-21 over I-77
Fairfield County, South Carolina · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- S-20-21 over I-77 in Fairfield County, South Carolina, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1979, making it 46 years old at the 2025 inventory.
- It carries about 125 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 82 of the 139 inventoried bridges in Fairfield County rated fair (59.0%); 8 (5.8%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated May 2023, on a 24-month routine inspection cycle.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (34.36248, -80.99686)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 6 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous steel frame |
| Length | about 332 ft |
| Location | 6MI SE Winnsboro |
| NBI structure number | 000000000007254 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | May 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the South Carolina department of transportation.
Busiest bridges in Fairfield County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I-77 over Center Creek | 1978 | 53,600 | Good |
| I-77 over Big Cedar Creek | 1978 | 53,600 | Fair |
| I-77 over Dutchmans Creek | 1978 | 48,900 | Fair |
| I-77 NB over Sc 34 | 1978 | 24,450 | Good |
| I-77 SB over Sc 34 | 1978 | 24,450 | Good |
| I-77 Nbl over Big Wateree Ck | 1979 | 24,300 | Fair |
All bridges nearby: Fairfield County, SC bridge conditions · every bridge in Fairfield County · South Carolina bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.