IRR/N12
Carrying IRR/N12 over STREAM
6E NIOBRARA, Knox, Nebraska
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
IRR/N12 in Knox, Nebraska sits above 23% of rated Nebraska bridges on inventory load rating (22 t), while its 1952 build year is earlier than 85% of Knox's recorded-year cohort (329 bridges).
IRR/N12 in Knox, Nebraska is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1952, it carries 1 rated component on the inspecting agency's 0-9 scale, and its weakest reported component scores 6. The lowest applicable rating sets the federal condition category, so this Fair 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 NE:S012 16723
INTERSTATE-ERA · CONCRETE · MULTI-SPAN · CULVERT-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-FAIR
- INTERSTATE-ERA 1950–1979
- CONCRETE Concrete
- MULTI-SPAN 3 spans
- CULVERT-LED Culvert-led
- ARTERIAL-ADT Arterial ADT
- STANDARD-LOAD Standard load
- CAT-FAIR Fair
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: IRR/N12
The IRR/N12 bridge in Knox, Nebraska carries IRR/N12 over STREAM. It was built in 1952, making it 74 years old today. The structure is built primarily of concrete and spans 3 sections, stretching 12.2 meters (40 feet) end to end. Daily traffic averages 1,235 vehicles, placing it in the moderately-trafficked tier of Nebraska bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show culvert at 6/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How IRR/N12 compares
Age against the county: built in 1952, earlier than 281 of Knox's 329 bridges with a recorded construction year (85%), against a county median build year of 1984. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Nebraska bridges with a recorded inventory load rating (15,392 of 15,398 rated).
IRR/N12 vs every rated Nebraska bridge
Inventory load rating (metric tons), FHWA NBI, this state
22 Top 77% higher than 23% of 15,392 bridges
rated Nebraska 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.
Knox inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 329 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
- 1952
- Material
- Concrete
- Number of Spans
- 3
- Structure Length
- 12.2 m (40 ft) 0
- Owner
- State Highway Agency
- Avg Daily Traffic
- 1,235 vehicles/day
- Structure Number
- S012 16723
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 IRR/N12 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 IRR/N12 against other structures in Knox and across Nebraska. Nebraska 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 IRR/N12?
IRR/N12 in Knox, Nebraska on the FHWA's 0–9 scale.
How often is IRR/N12 inspected?
IRR/N12'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 1,235 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IRR/N12 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 IRR/N12?
IRR/N12 has an NBI inventory load rating of 22.0 metric tons.
Who is responsible for maintaining IRR/N12?
IRR/N12 is owned and maintained by State Highway Agency.
How old is IRR/N12 and does age affect safety?
IRR/N12 was built in 1952, making it 74 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.