NM-406
Carrying NM-406 over NORTH CANADIAN RIVER
19.2 MI N OF JCT US-56/64, Union, New Mexico
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
NM-406 in Union, New Mexico sits above 27% of rated New Mexico bridges on inventory load rating (32 t), while its 1977 build year is earlier than 41% of Union's recorded-year cohort (68 bridges).
NM-406 in Union, New Mexico is rated Fair in the FHWA's 2024 National Bridge Inventory. Built in 1977, it carries 3 rated components 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 NM:000000000007648
INTERSTATE-ERA · PRESTRESS · LONG-SPAN-RUN · SUPER-LED · LOCAL-ADT · STANDARD-LOAD · CAT-FAIR
- INTERSTATE-ERA 1950–1979
- PRESTRESS Prestressed concrete
- LONG-SPAN-RUN 4 spans
- SUPER-LED Superstructure-led
- LOCAL-ADT Local 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: NM-406
The NM-406 bridge in Union, New Mexico carries NM-406 over NORTH CANADIAN RIVER. It was built in 1977, making it 49 years old today. The structure is built primarily of prestressed concrete continuous and spans 4 sections, stretching 61.3 meters (201 feet) end to end. Daily traffic averages 159 vehicles, placing it in the lower-traffic tier of New Mexico bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 6/9, substructure at 7/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range.
How NM-406 compares
Age against the county: built in 1977, earlier than 28 of Union's 68 bridges with a recorded construction year (41%), against a county median build year of 1976. This is one of the newer structures in its county.
Live comparison across New Mexico bridges with a recorded inventory load rating (4,030 of 4,035 rated).
NM-406 vs every rated New Mexico bridge
Inventory load rating (metric tons), FHWA NBI, this state
32 Top 73% higher than 27% of 4,030 bridges
rated New Mexico 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.
Union inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 68 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
- 1977
- Material
- Prestressed Concrete Continuous
- Number of Spans
- 4
- Structure Length
- 61.3 m (201 ft)
- Deck Width
- 10.7 m (35 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 159 vehicles/day
- Structure Number
- 000000000007648
Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
- • The substructure (piers and abutments) rates good at 7/9, with no significant deterioration on file.
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 NM-406 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 NM-406 against other structures in Union and across New Mexico. New Mexico 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 NM-406?
NM-406 in Union, New Mexico has a deck rating of 7/9, superstructure rating of 6/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is NM-406 inspected?
NM-406'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 159 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. NM-406 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 NM-406?
NM-406 has an NBI inventory load rating of 32.0 metric tons.
Who is responsible for maintaining NM-406?
NM-406 is owned and maintained by State Highway Agency.
How old is NM-406 and does age affect safety?
NM-406 was built in 1977, making it 49 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.