IRR BIA RTE 56
Carrying IRR BIA RTE 56 over USBR DRAIN
3 KM WEST OF BIA 1, La Paz, Arizona
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
IRR BIA RTE 56 in La Paz, Arizona sits above 2% of rated Arizona bridges on inventory load rating (22 t), while its 1968 build year is earlier than 34% of La Paz's recorded-year cohort (306 bridges).
IRR BIA RTE 56 in La Paz, Arizona is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1968, 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:00000000000H033
INTERSTATE-ERA · CONCRETE · MULTI-SPAN · DECK-LED · LOCAL-ADT · STANDARD-LOAD · CAT-POOR
- INTERSTATE-ERA 1950–1979
- CONCRETE Concrete
- MULTI-SPAN 3 spans
- DECK-LED Deck-led
- LOCAL-ADT Local ADT
- STANDARD-LOAD Standard 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 56
The IRR BIA RTE 56 bridge in La Paz, Arizona carries IRR BIA RTE 56 over USBR DRAIN. It was built in 1968, making it 58 years old today. The structure is built primarily of concrete and spans 3 sections, stretching 22.6 meters (74 feet) end to end. Daily traffic averages 55 vehicles, placing it in the lower-traffic 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 7/9, substructure at 5/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed.
How IRR BIA RTE 56 compares
Age against the county: built in 1968, earlier than 103 of La Paz's 306 bridges with a recorded construction year (34%), against a county median build year of 1967. This is one of the newer structures in its county.
Live comparison across Arizona bridges with a recorded inventory load rating (8,572 of 8,573 rated).
IRR BIA RTE 56 vs every rated Arizona bridge
Inventory load rating (metric tons), FHWA NBI, this state
22 Top 98% higher than 2% 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.
La Paz inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 306 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
- 1968
- Material
- Concrete
- Number of Spans
- 3
- Structure Length
- 22.6 m (74 ft)
- Deck Width
- 8.3 m (27 ft)
- Owner
- Bureau of Indian Affairs
- Avg Daily Traffic
- 55 vehicles/day
- Structure Number
- 00000000000H033
Condition Analysis
- • At 4/9, the deck (driving surface) is in poor shape, with advanced wear on file for this vintage.
- • The superstructure (beams and supports above the deck) is in good condition (7/9), showing no significant deterioration.
- • The substructure (piers and abutments) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
IRR BIA RTE 56 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 56 against other structures in La Paz 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 56?
IRR BIA RTE 56 in La Paz, Arizona has a deck rating of 4/9, superstructure rating of 7/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is IRR BIA RTE 56 inspected?
IRR BIA RTE 56'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 55 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 56 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 56?
IRR BIA RTE 56 has an NBI inventory load rating of 21.7 metric tons.
Who is responsible for maintaining IRR BIA RTE 56?
IRR BIA RTE 56 is owned and maintained by Bureau of Indian Affairs.
How old is IRR BIA RTE 56 and does age affect safety?
IRR BIA RTE 56 was built in 1968, making it 58 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.