US421 SBL
Carrying US421 SBL over YADKIN RIVER
1.1 MI. S. JCT. SR1301, Forsyth, North Carolina
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: US421 SBL
The US421 SBL bridge in Forsyth, North Carolina carries US421 SBL over YADKIN RIVER. It was built in 1973, making it 53 years old today. The structure is built primarily of steel continuous and spans 5 sections, stretching 189.2 meters (621 feet) end to end. Daily traffic averages 12,000 vehicles, placing it in the heavily-trafficked tier of North Carolina bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 5/9, substructure at 6/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 25.4 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How US421 SBL compares
Live comparison across North Carolina.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1973
- Material
- Steel Continuous
- Number of Spans
- 5
- Structure Length
- 189.2 m (621 ft)
- Deck Width
- 12.8 m (42 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 12,000 vehicles/day
- Structure Number
- 000000000670051
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • The superstructure (beams and supports above the deck) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) rates fair at 6/9, minor deterioration that routine maintenance should address.
How to read this record
This page shows what the last federal inspection recorded, not whether US421 SBL is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Learn how the 0–9 condition scale and Good/Fair/Poor categories are defined. How condition ratings work
- Compare US421 SBL against other structures in Forsyth and across North Carolina. North Carolina bridges
- Noticed visible damage or a safety concern? Report it to the agency that owns the bridge, or call 911 in an emergency. How to report a bridge
Condition codes come straight from the FHWA National Bridge Inventory and are not a real-time safety judgment. Only the owning agency, a state DOT, county, or other owner, can post, restrict, or close a bridge.
Frequently Asked Questions
What do the condition ratings mean for US421 SBL?
US421 SBL in Forsyth, North Carolina has a deck rating of 6/9, superstructure rating of 5/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is US421 SBL inspected?
US421 SBL's responsible agency sets its routine interval under FHWA's risk-based inspection rules; this page does not expose the scheduled interval. It carries about 12,000 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. US421 SBL is currently shown as Fair condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for US421 SBL?
US421 SBL has an NBI inventory load rating of 25.4 metric tons.
Who is responsible for maintaining US421 SBL?
US421 SBL is owned and maintained by State Highway Agency.
How old is US421 SBL and does age affect safety?
US421 SBL was built in 1973, making it 53 years old.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A Poor condition rating is not a live declaration that a bridge is closed or unsafe for travel. For current closure, posting, or safety information, contact the responsible transportation agency.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.