Co. Highway
Carrying Co. Highway over Des Moines River
Red Rock Dam, Marion, Iowa
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: Co. Highway
The Co. Highway bridge in Marion, Iowa carries Co. Highway over Des Moines River. It was built in 1967, making it 59 years old today. The structure is built primarily of prestressed concrete and spans 5 sections, stretching 72.2 meters (237 feet) end to end. Daily traffic averages 3,750 vehicles, placing it in the moderately-trafficked tier of Iowa bridges. It is owned and maintained by Army Corps of Engineers.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. All reported major components score above the Poor range. Its NBI inventory load rating is 34.7 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How Co. Highway 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 How the historical reference is calculated.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
- 1967
- Material
- Prestressed Concrete
- Number of Spans
- 5
- Structure Length
- 72.2 m (237 ft)
- Deck Width
- 11.0 m (36 ft)
- Owner
- Army Corps of Engineers
- Avg Daily Traffic
- 3,750 vehicles/day
- Structure Number
- 240385
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 5/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
- • The substructure (piers and abutments) rates fair at 6/9, minor deterioration that routine maintenance should address.
How to read this record
This page shows what the last federal inspection recorded, not whether Co. Highway 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 Co. Highway against other structures in Marion 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 Co. Highway?
Co. Highway in Marion, Iowa has a deck rating of 5/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is Co. Highway inspected?
Co. Highway'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 3,750 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. Co. Highway 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 Co. Highway?
Co. Highway has an NBI inventory load rating of 34.7 metric tons.
Who is responsible for maintaining Co. Highway?
Co. Highway is owned and maintained by Army Corps of Engineers.
How old is Co. Highway and does age affect safety?
Co. Highway was built in 1967, making it 59 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.
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.