FM - 335TH ST
Carrying FM - 335TH ST over MOSQUITO CREEK
078413203, Harrison, Iowa
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: FM - 335TH ST
The FM - 335TH ST bridge in Harrison, Iowa carries FM - 335TH ST over MOSQUITO CREEK. It was built in 1920, making it 106 years old today. It was last reconstructed in 1945, extending its service life. The structure is built primarily of steel and spans 1 section, stretching 73.5 meters (241 feet) end to end. Daily traffic averages 120 vehicles, placing it in the lower-traffic 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 6/9, substructure at 5/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 12.0 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How FM - 335TH ST compares
Live comparison across Iowa.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1920
- Last Reconstructed
- 1945
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 73.5 m (241 ft)
- Deck Width
- 6.1 m (20 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 120 vehicles/day
- Structure Number
- 000000000177110
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • At 5/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
This page shows what the last federal inspection recorded, not whether FM - 335TH ST 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 FM - 335TH ST against other structures in Harrison 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 FM - 335TH ST?
FM - 335TH ST in Harrison, Iowa has a deck rating of 5/9, superstructure rating of 6/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is FM - 335TH ST inspected?
FM - 335TH ST'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 120 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. FM - 335TH ST 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 FM - 335TH ST?
FM - 335TH ST has an NBI inventory load rating of 12.0 metric tons.
Who is responsible for maintaining FM - 335TH ST?
FM - 335TH ST is owned and maintained by County Highway Agency.
How old is FM - 335TH ST and does age affect safety?
FM - 335TH ST was built in 1920, making it 106 years old and last reconstructed in 1945.
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.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.