FHWA NBI 2024 Inspection record Public-domain dataset

TROY MILLS RD

Carrying TROY MILLS RD over TRIB.TO WAPSIPINICON R

086071704, Linn, Iowa

Inventory: FHWA NBI 2024 · last ETL August 2026

FHWA NBI record, refreshed with each annual release.

Fair
36 t Inventory load rating Higher than 73% of rated Iowa bridges

TROY MILLS RD in Linn, Iowa sits above 73% of rated Iowa bridges on inventory load rating (36 t), while its 1925 build year is earlier than 97% of Linn's recorded-year cohort (506 bridges).

TROY MILLS RD in Linn, Iowa is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1925, 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:000000000223240

PRE-1950 · CONCRETE · MULTI-SPAN · CULVERT-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-FAIR

  • PRE-1950 Pre-1950
  • CONCRETE Concrete
  • MULTI-SPAN 2 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: TROY MILLS RD

The TROY MILLS RD bridge in Linn, Iowa carries TROY MILLS RD over TRIB.TO WAPSIPINICON R. It was built in 1925, making it 101 years old today. It was last reconstructed in 1977, extending its service life. The structure is built primarily of concrete continuous and spans 2 sections, stretching 7.6 meters (25 feet) end to end. Daily traffic averages 1,424 vehicles, placing it in the moderately-trafficked tier of Iowa bridges. It is owned and maintained by County 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 TROY MILLS RD compares

▲ 5.6
Load rating vs Iowa average (30.4 t; 23,718 of 23,719 rated)
506
Bridges in Linn · 32 in Poor condition

Age against the county: built in 1925, earlier than 492 of Linn's 506 bridges with a recorded construction year (97%), against a county median build year of 1989. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.

TROY MILLS RD 36.0 t
Iowa average (23,718 of 23,719 rated) 30.4 t

Live comparison across Iowa bridges with a recorded inventory load rating (23,718 of 23,719 rated).

TROY MILLS RD vs every rated Iowa bridge

Inventory load rating (metric tons), FHWA NBI, this state

36 Top 27% higher than 73% 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

Culvert
6/9
Fair (5–6)
Inventory Load Rating
36.0 t
NBI inventory level (metric tons)
Overall Condition
Fair

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Linn inventory by recorded NBI category

Exclusive Good/Fair/Poor bands across all 506 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
1925
Last Reconstructed
1977
Material
Concrete Continuous
Number of Spans
2
Structure Length
7.6 m (25 ft)
0
Owner
County Highway Agency
Avg Daily Traffic
1,424 vehicles/day
Structure Number
000000000223240

How to read this record

This page shows what the last federal inspection recorded, not whether TROY MILLS RD 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 TROY MILLS RD against other structures in Linn 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 TROY MILLS RD?

TROY MILLS RD in Linn, Iowa on the FHWA's 0–9 scale.

How often is TROY MILLS RD inspected?

TROY MILLS RD'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 1,424 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. TROY MILLS RD 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 TROY MILLS RD?

TROY MILLS RD has an NBI inventory load rating of 36.0 metric tons.

Who is responsible for maintaining TROY MILLS RD?

TROY MILLS RD is owned and maintained by County Highway Agency.

How old is TROY MILLS RD and does age affect safety?

TROY MILLS RD was built in 1925, making it 101 years old and last reconstructed in 1977.

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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.

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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.