TROY MILLS RD
Carrying TROY MILLS RD over WAPSIPINICON RIVER
086070522, Linn, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
TROY MILLS RD in Linn, Iowa sits above 36% of rated Iowa bridges on inventory load rating (26 t), while its 1951 build year is earlier than 93% 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 1951, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 5. 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:000000000223180
INTERSTATE-ERA · STEEL · LONG-SPAN-RUN · TIED-CTRL · ARTERIAL-ADT · STANDARD-LOAD · CAT-FAIR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- LONG-SPAN-RUN 4 spans
- TIED-CTRL Tied control
- 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 WAPSIPINICON RIVER. It was built in 1951, making it 75 years old today. It was last reconstructed in 1991, extending its service life. The structure is built primarily of steel continuous and spans 4 sections, stretching 136.6 meters (448 feet) end to end. Daily traffic averages 2,033 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 a deck rating of 5/9, superstructure at 5/9, substructure at 5/9. The weakest component sits in fair condition. All reported major components score above the Poor range.
How TROY MILLS RD compares
Age against the county: built in 1951, earlier than 470 of Linn's 506 bridges with a recorded construction year (93%), 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.
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
26 Top 64% higher than 36% 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.
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.
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
- 1951
- Last Reconstructed
- 1991
- Material
- Steel Continuous
- Number of Spans
- 4
- Structure Length
- 136.6 m (448 ft)
- Deck Width
- 9.8 m (32 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 2,033 vehicles/day
- Structure Number
- 000000000223180
Condition Analysis
- • At 5/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • At 5/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
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 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 has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 5/9 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 2,033 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 26.2 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 1951, making it 75 years old and last reconstructed in 1991.
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.