IRR BIA RTE 31
Carrying IRR BIA RTE 31 over SOUTHERN PACIFIC RR
IN FORT YUMA SUB-AGENCY, Yuma, Arizona
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
IRR BIA RTE 31 in Yuma, Arizona sits above 1% of rated Arizona bridges on inventory load rating (10 t), while its 1965 build year is earlier than 69% of Yuma's recorded-year cohort (262 bridges).
IRR BIA RTE 31 in Yuma, Arizona is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1965, 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 AZ:00000000000H050
INTERSTATE-ERA · STEEL · MULTI-SPAN · TIED-CTRL · ARTERIAL-ADT · LIGHT-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- STEEL Steel
- MULTI-SPAN 3 spans
- TIED-CTRL Tied control
- ARTERIAL-ADT Arterial ADT
- LIGHT-LOAD Light 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: IRR BIA RTE 31
The IRR BIA RTE 31 bridge in Yuma, Arizona carries IRR BIA RTE 31 over SOUTHERN PACIFIC RR. It was built in 1965, making it 61 years old today. The structure is built primarily of steel and spans 3 sections, stretching 35.9 meters (118 feet) end to end. Daily traffic averages 3,550 vehicles, placing it in the moderately-trafficked tier of Arizona bridges. It is owned and maintained by Bureau of Indian Affairs.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 4/9, substructure at 5/9. 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 IRR BIA RTE 31 compares
Age against the county: built in 1965, earlier than 182 of Yuma's 262 bridges with a recorded construction year (69%), against a county median build year of 1968. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across Arizona bridges with a recorded inventory load rating (8,572 of 8,573 rated).
IRR BIA RTE 31 vs every rated Arizona bridge
Inventory load rating (metric tons), FHWA NBI, this state
10 Top 99% higher than 1% of 8,572 bridges
rated Arizona 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.
Yuma inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 262 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
- 1965
- Material
- Steel
- Number of Spans
- 3
- Structure Length
- 35.9 m (118 ft)
- Deck Width
- 10.2 m (33 ft)
- Owner
- Bureau of Indian Affairs
- Avg Daily Traffic
- 3,550 vehicles/day
- Structure Number
- 00000000000H050
Condition Analysis
- • The deck (driving surface) rates poor at 4/9, with advanced deterioration recorded on the latest inspection.
- • At 4/9, the superstructure (beams and supports above the deck) is in poor shape, with advanced wear on file for this vintage.
- • At 5/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
IRR BIA RTE 31 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 IRR BIA RTE 31 against other structures in Yuma and across Arizona. Arizona 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 IRR BIA RTE 31?
IRR BIA RTE 31 in Yuma, Arizona has a deck rating of 4/9, superstructure rating of 4/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is IRR BIA RTE 31 inspected?
IRR BIA RTE 31'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 3,550 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IRR BIA RTE 31 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 IRR BIA RTE 31?
IRR BIA RTE 31 has an NBI inventory load rating of 10.1 metric tons.
Who is responsible for maintaining IRR BIA RTE 31?
IRR BIA RTE 31 is owned and maintained by Bureau of Indian Affairs.
How old is IRR BIA RTE 31 and does age affect safety?
IRR BIA RTE 31 was built in 1965, making it 61 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.