FM 120TH ST
Carrying FM 120TH ST over BR PLUM CR
081081201, Johnson, Iowa
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
FM 120TH ST in Johnson, Iowa sits above 73% of rated Iowa bridges on inventory load rating (36 t), while its 1989 build year is earlier than 38% of Johnson's recorded-year cohort (372 bridges).
FM 120TH ST in Johnson, Iowa is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1989, 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:000000000205791
LATE-CENTURY · CONCRETE · MULTI-SPAN · CULVERT-LED · ARTERIAL-ADT · STANDARD-LOAD · CAT-FAIR
- LATE-CENTURY 1980–1999
- 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: FM 120TH ST
The FM 120TH ST bridge in Johnson, Iowa carries FM 120TH ST over BR PLUM CR. It was built in 1989, making it 37 years old today. The structure is built primarily of concrete continuous and spans 2 sections, stretching 6.4 meters (21 feet) end to end. Daily traffic averages 1,630 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. No reported major component scores in the Poor range under the current federal condition thresholds.
How FM 120TH ST compares
Age against the county: built in 1989, earlier than 143 of Johnson's 372 bridges with a recorded construction year (38%), against a county median build year of 1979. This is one of the newer structures in its county.
Live comparison across Iowa bridges with a recorded inventory load rating (23,718 of 23,719 rated).
FM 120TH ST 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
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Johnson inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 372 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
- 1989
- Material
- Concrete Continuous
- Number of Spans
- 2
- Structure Length
- 6.4 m (21 ft) 0
- Owner
- County Highway Agency
- Avg Daily Traffic
- 1,630 vehicles/day
- Structure Number
- 000000000205791
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 FM 120TH 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 120TH ST against other structures in Johnson 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 120TH ST?
FM 120TH ST in Johnson, Iowa on the FHWA's 0–9 scale.
How often is FM 120TH ST inspected?
FM 120TH 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 1,630 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. FM 120TH 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 120TH ST?
FM 120TH ST has an NBI inventory load rating of 36.0 metric tons.
Who is responsible for maintaining FM 120TH ST?
FM 120TH ST is owned and maintained by County Highway Agency.
How old is FM 120TH ST and does age affect safety?
FM 120TH ST was built in 1989, making it 37 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.
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.