N4120
Carrying N4120 over N. FORK OF ASH CREEK
3.2N;2W OF SH16 & 72, Muskogee, Oklahoma
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
N4120 in Muskogee, Oklahoma sits above 81% of rated Oklahoma bridges on inventory load rating (41 t), while its 1982 build year is earlier than 32% of Muskogee's recorded-year cohort (398 bridges).
N4120 in Muskogee, Oklahoma is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1982, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor 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 OK:202000000000000
LATE-CENTURY · PRESTRESS · SINGLE-SPAN · SUB-LED · LOCAL-ADT · HEAVY-LOAD · CAT-POOR
- LATE-CENTURY 1980–1999
- PRESTRESS Prestressed concrete
- SINGLE-SPAN Single span
- SUB-LED Substructure-led
- LOCAL-ADT Local ADT
- HEAVY-LOAD Heavy load
- CAT-POOR Poor
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: N4120
The N4120 bridge in Muskogee, Oklahoma carries N4120 over N. FORK OF ASH CREEK. It was built in 1982, making it 44 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 20.7 meters (68 feet) end to end. Daily traffic averages 100 vehicles, placing it in the lower-traffic tier of Oklahoma 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 4/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order.
How N4120 compares
Age against the county: built in 1982, earlier than 129 of Muskogee's 398 bridges with a recorded construction year (32%), against a county median build year of 1969. This is one of the newer structures in its county.
Live comparison across Oklahoma bridges with a recorded inventory load rating (22,909 of 22,917 rated).
N4120 vs every rated Oklahoma bridge
Inventory load rating (metric tons), FHWA NBI, this state
41 Top 19% higher than 81% of 22,909 bridges
rated Oklahoma 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.
Muskogee inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 398 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
- 1982
- Material
- Prestressed Concrete
- Number of Spans
- 1
- Structure Length
- 20.7 m (68 ft)
- Deck Width
- 8.7 m (29 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 100 vehicles/day
- Structure Number
- 202000000000000
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 4/9, the substructure (piers and abutments) is in poor shape, with advanced wear on file for this vintage.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
N4120 is in the federal Poor condition category. That is a component-based result, not a closure order.
- NBI condition ratings reflect the latest record in this annual dataset, not a live status. Current routine inspection intervals are risk-based.
- Understand what Poor condition does and does not mean before drawing conclusions. Poor condition explained
- Compare N4120 against other structures in Muskogee and across Oklahoma. Oklahoma 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 N4120?
N4120 in Muskogee, Oklahoma has a deck rating of 5/9, superstructure rating of 5/9, and substructure rating of 4/9 on the FHWA's 0–9 scale.
How often is N4120 inspected?
N4120'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 100 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. N4120 is currently shown as Poor condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for N4120?
N4120 has an NBI inventory load rating of 40.8 metric tons.
Who is responsible for maintaining N4120?
N4120 is owned and maintained by County Highway Agency.
How old is N4120 and does age affect safety?
N4120 was built in 1982, making it 44 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.