I73 US421N
Carrying I73 US421N over SR1546
0.3 MI. W. JCT. SR1541, Guilford, North Carolina
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
I73 US421N in Guilford, North Carolina sits above 34% of rated North Carolina bridges on inventory load rating (34 t), while its 2008 build year is earlier than 23% of Guilford's recorded-year cohort (736 bridges).
I73 US421N in Guilford, North Carolina is rated Good in the FHWA's 2024 National Bridge Inventory. Built in 2008, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 7. The lowest applicable rating sets the federal condition category, so this Good result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure NC:000000000810867
POST-2000 · PRESTRESS · MULTI-SPAN · TIED-CTRL · HEAVY-ADT · STANDARD-LOAD · CAT-GOOD
- POST-2000 2000+
- PRESTRESS Prestressed concrete
- MULTI-SPAN 3 spans
- TIED-CTRL Tied control
- HEAVY-ADT Heavy ADT
- STANDARD-LOAD Standard load
- CAT-GOOD Good
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: I73 US421N
The I73 US421N bridge in Guilford, North Carolina carries I73 US421N over SR1546. It was built in 2008, making it 18 years old today. The structure is built primarily of prestressed concrete continuous and spans 3 sections, stretching 54.2 meters (178 feet) end to end. Daily traffic averages 32,250 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 7/9, superstructure at 8/9, substructure at 7/9. The weakest component sits in good condition. All reported major components score above the Poor range.
How I73 US421N compares
Age against the county: built in 2008, earlier than 172 of Guilford's 736 bridges with a recorded construction year (23%), against a county median build year of 1996. This is one of the newer structures in its county.
Live comparison across North Carolina bridges with a recorded inventory load rating (19,160 of 19,210 rated).
I73 US421N vs every rated North Carolina bridge
Inventory load rating (metric tons), FHWA NBI, this state
34 Top 66% higher than 34% of 19,160 bridges
rated North Carolina bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Guilford inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 736 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 2008
- Material
- Prestressed Concrete Continuous
- Number of Spans
- 3
- Structure Length
- 54.2 m (178 ft)
- Deck Width
- 25.1 m (82 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 32,250 vehicles/day
- Structure Number
- 000000000810867
Condition Analysis
- • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
- • The superstructure (beams and supports above the deck) rates good at 8/9, with no significant deterioration on file.
- • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
This page shows what the last federal inspection recorded, not whether I73 US421N 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 I73 US421N against other structures in Guilford 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 I73 US421N?
I73 US421N in Guilford, North Carolina has a deck rating of 7/9, superstructure rating of 8/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is I73 US421N inspected?
I73 US421N'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 32,250 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. I73 US421N is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for I73 US421N?
I73 US421N has an NBI inventory load rating of 34.4 metric tons.
Who is responsible for maintaining I73 US421N?
I73 US421N is owned and maintained by State Highway Agency.
How old is I73 US421N and does age affect safety?
I73 US421N was built in 2008, making it 18 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.