US421N over Big Alamance Creek
Guilford County, North Carolina · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- US421N over Big Alamance Creek in Guilford County, North 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 1969, making it 56 years old at the 2025 inventory.
- It carries about 14,000 vehicles a day (traffic count year 2021).
- Its listed owner is the state highway agency.
- It is one of 284 of the 744 inventoried bridges in Guilford County rated fair (38.2%); 33 (4.4%) 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 April 2024, 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 → (35.95823, -79.69622)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 6 | 6 | Satisfactory condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Steel stringer or multi-beam girder |
| Length | about 155 ft |
| Location | 0.5 Mi S Jct SR3389 |
| NBI structure number | 000000000810278 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | April 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the North Carolina department of transportation.
Busiest bridges in Guilford County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I40 85 US29 70 220 over South Buffalo Creek | 1955 | 120,000 | Fair |
| I40 US421 over NC68 | 1981 | 120,000 | Fair |
| I40 & I85 SR3143 over North Alamance Creek | 1954 | 119,000 | Fair |
| I40 I85 over Rock Creek | 1954 | 119,000 | Fair |
| I40 I85 Bus US29 over Branch South Buffalo Crk | 1954 | 118,000 | Fair |
| I40 over SR4121 | 1976 | 115,000 | Fair |
All bridges nearby: Guilford County, NC bridge conditions · every bridge in Guilford County · North Carolina bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.