F24
Carrying F24 over SMALL STREAM
081383501, Shelby, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
F24 in Shelby, Iowa sits above 56% of rated Iowa bridges on inventory load rating (33 t), while its 1937 build year is earlier than 95% of Shelby's recorded-year cohort (207 bridges).
F24 in Shelby, Iowa is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1937, 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 IA:000000000047920
PRE-1950 · CONCRETE · SINGLE-SPAN · CULVERT-LED · LOCAL-ADT · STANDARD-LOAD · CAT-FAIR
- PRE-1950 Pre-1950
- CONCRETE Concrete
- SINGLE-SPAN Single span
- CULVERT-LED Culvert-led
- LOCAL-ADT Local 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.
Structural health score
A composite of the deck, superstructure, and substructure NBI condition ratings plus the inventory load rating, benchmarked against the full national bridge corpus, distinct from the Good/Fair/Poor category above.
Bridge Snapshot: F24
The F24 bridge in Shelby, Iowa carries F24 over SMALL STREAM. It was built in 1937, making it 89 years old today. The structure is built primarily of concrete and spans 1 section, stretching 9.8 meters (32 feet) end to end. Daily traffic averages 417 vehicles, placing it in the lower-traffic tier of Iowa bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection places the weakest component in fair condition (see the full component ratings below). No reported major component scores in the Poor range under the current federal condition thresholds.
How F24 compares
Age against the county: built in 1937, earlier than 196 of Shelby's 207 bridges with a recorded construction year (95%), against a county median build year of 1978. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Iowa bridges with a recorded inventory load rating (23,718 of 23,719 rated).
F24 vs every rated Iowa bridge
Inventory load rating (metric tons), FHWA NBI, this state
33 Top 44% higher than 56% of 23,718 bridges
rated Iowa 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.
Shelby inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 207 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
- 1937
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 9.8 m (32 ft) 0
- Owner
- County Highway Agency
- Avg Daily Traffic
- 417 vehicles/day
- Structure Number
- 000000000047920
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 F24 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 F24 against other structures in Shelby and across Iowa. Iowa 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 F24?
F24 in Shelby, Iowa on the FHWA's 0–9 scale.
How often is F24 inspected?
F24'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 417 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. F24 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 F24?
F24 has an NBI inventory load rating of 32.7 metric tons.
Who is responsible for maintaining F24?
F24 is owned and maintained by County Highway Agency.
How old is F24 and does age affect safety?
F24 was built in 1937, making it 89 years old.
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.