I77 SBL
Carrying I77 SBL over I-L CREEK
1.0 MI. S. JCT. SR2342, Iredell, North Carolina
FHWA NBI inspection record for this structure. Condition ratings, inventory load rating, span, deck width, and average daily traffic refresh annually with each NBI release.
Bridge Snapshot: I77 SBL
The I77 SBL bridge in Iredell, North Carolina carries I77 SBL over I-L CREEK. It was built in 1968, making it 58 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 12.4 meters (41 feet) end to end. Daily traffic averages 29,250 vehicles, placing it in the heavily-trafficked tier of North Carolina bridges. It is owned and maintained by State Highway Agency, the entity responsible for routine inspections and any needed repairs.
The latest FHWA inspection records show culvert at 5/9 on the 0–9 NBI scale, where 9 is excellent and 0 is failed. The weakest component sits in fair condition, which drives the overall status of this bridge. No major component scores in the poor range, so the bridge is not classified as structurally deficient under federal criteria. Its NBI inventory load rating is 32.6 metric tons — the load level the structure is rated to carry at inventory (long-term) level.
In a county that maintains hundreds of NBI-tracked bridges, I77 SBL is one data point in a North Carolina inventory that FHWA inspects on a two-year cycle (more often when ratings fall). Bridge age alone is not a reliable safety signal — a 58-era structure can outperform a newer one when maintenance is consistent, materials are sound, and traffic loads stay within design limits. Use the condition ratings above, the inventory load rating, and the structurally-deficient flag together to read the bridge's real status, and check the linked county and state pages to see how this bridge ranks against its peers.
Every figure on this page comes directly from the Federal Highway Administration National Bridge Inventory (NBI), the public dataset that catalogs more than 575,000 highway bridges across the United States and is updated annually from the records that each state Department of Transportation submits to the FHWA. The condition codes use the standardized FHWA Recording and Coding Guide, the same scale that determines federal eligibility for the Highway Bridge Program and the Surface Transportation Block Grant set-aside for off-system bridges. A "structurally deficient" classification under those federal criteria is a maintenance and funding flag, never a closure order; states keep deficient bridges open with load posting, weight limits, or accelerated inspection cycles until rehabilitation or replacement is funded. See our methodology for refresh cadence and the exact NBI release vintage powering each record.
How I77 SBL compares
NBI inventory load rating (metric tons) and structural-deficiency status compared across North Carolina, computed live from the FHWA NBI.
Sufficiency Rating
PlainBridge-computedComputed by PlainBridge from the published FHWA NBI items using the agency's historical sufficiency-rating formula (Recording & Coding Guide, Appendix B). The FHWA itself no longer publishes this composite — see how it is calculated.
Condition Ratings
Ratings are on a 0–9 scale: 9 = Excellent, 7–8 = Good, 5–6 = Fair, 3–4 = Poor, 0–2 = Critical/Failed. Sufficiency rating (0–100) combines structural adequacy, functional obsolescence, and essentiality.
Structural Details
- Year Built
- 1968
- Material
- Concrete Continuous
- Number of Spans
- 3
- Structure Length
- 12.4 m (41 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 29,250 vehicles/day
- Structure Number
- 000000000970122
Location
Data Source
Data from the FHWA National Bridge Inventory (NBI). Bridge inspections are required every two years by federal law. Conditions reflect the most recent inspection.
FHWA NBI Program ↗Guides
How to read this record
This page shows what the last federal inspection recorded — not whether I77 SBL is safe to cross today. Here is how to use it.
- NBI condition ratings reflect the most recent inspection, which can be up to 24 months old — treat them as a snapshot, not a live status.
- Learn how the 0–9 condition scale and the structurally-deficient flag are defined. How condition ratings work
- Compare I77 SBL against other structures in Iredell 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 I77 SBL?
Bridge condition ratings use a 0–9 scale set by the Federal Highway Administration (FHWA). Ratings 7–9 indicate good condition with no significant problems. Ratings 5–6 mean fair condition with minor issues. Ratings 3–4 indicate poor condition requiring repair. Ratings 0–2 are critical, meaning the bridge has serious structural problems. I77 SBL in Iredell, North Carolina.
How often is I77 SBL inspected?
Federal law requires most highway bridges to be inspected at least every 24 months. Bridges in poor condition or with known issues may be inspected more frequently (every 12 months or less). I77 SBL is part of the National Bridge Inventory maintained by the FHWA. With 29,250 vehicles crossing daily, regular inspection is essential.
What does "structurally deficient" mean for a bridge?
A structurally deficient bridge has at least one major component (deck, superstructure, or substructure) rated 4 or below on the FHWA 0–9 scale. This classification does NOT mean the bridge is unsafe for travel — it means the bridge needs repair, rehabilitation, or eventual replacement. Structurally deficient bridges remain open and are monitored. I77 SBL is not classified as structurally deficient.
What is the inventory load rating for I77 SBL?
The NBI inventory rating is the load level a bridge is rated to carry for an indefinite period, recorded in metric tons. A lower number means the structure is more load-restricted. I77 SBL has an inventory load rating of 32.6 metric tons. It is distinct from the FHWA sufficiency rating, a separate 0–100 funding-eligibility score that this dataset does not include.
Who is responsible for maintaining I77 SBL?
Bridge ownership and maintenance responsibility varies — bridges may be owned by state DOTs, counties, cities, railroads, or federal agencies. I77 SBL is maintained by State Highway Agency. The FHWA oversees the National Bridge Inventory program and sets inspection standards, but day-to-day maintenance falls to the owning agency. If you notice damage or safety concerns, contact your state DOT or call 911 for emergencies.
How old is I77 SBL and does age affect safety?
I77 SBL was built in 1968, making it 58 years old. Bridge age alone does not determine safety — condition depends on materials, design, traffic load, maintenance history, and environmental exposure. Many older bridges remain in good condition due to regular maintenance and reconstruction.
Disclaimer: Bridge condition data is from the FHWA NBI and reflects the last reported inspection. A structurally deficient rating does not mean a bridge is closed or unsafe for travel — it indicates the bridge requires repair or replacement. For current closure or safety information, contact your state DOT.
Read our methodology — how this data is sourced, computed, and verified.