MO 143 S
Carrying MO 143 S over BIG CR
S 8 T 30 N R 4 E, Iron, Missouri
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: MO 143 S
The MO 143 S bridge in Iron, Missouri carries MO 143 S over BIG CR. It was built in 1933, making it 93 years old today. The structure is built primarily of concrete and spans 5 sections, stretching 72.5 meters (238 feet) end to end. Daily traffic averages 590 vehicles, placing it in the lower-traffic tier of Missouri bridges. It is owned and maintained by State 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. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 20.7 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How MO 143 S compares
Live comparison across Missouri.
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 How the historical reference is calculated.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
- 1933
- Material
- Concrete
- Number of Spans
- 5
- Structure Length
- 72.5 m (238 ft)
- Deck Width
- 7.0 m (23 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 590 vehicles/day
- Structure Number
- 8996
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 5/9, 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 MO 143 S 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 MO 143 S against other structures in Iron and across Missouri. Missouri 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 MO 143 S?
MO 143 S in Iron, Missouri 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 MO 143 S inspected?
MO 143 S'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 590 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. MO 143 S 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 MO 143 S?
MO 143 S has an NBI inventory load rating of 20.7 metric tons.
Who is responsible for maintaining MO 143 S?
MO 143 S is owned and maintained by State Highway Agency.
How old is MO 143 S and does age affect safety?
MO 143 S was built in 1933, making it 93 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.