IRR ROUTE 46
Carrying IRR ROUTE 46 over BIG SANDY CREEK
11 KM NNW OF BOX ELDER, Hill, Montana
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: IRR ROUTE 46
The IRR ROUTE 46 bridge in Hill, Montana carries IRR ROUTE 46 over BIG SANDY CREEK. It was built in 1963, making it 63 years old today. The structure is built primarily of concrete and spans 1 section, stretching 7.7 meters (25 feet) end to end. Daily traffic averages 100 vehicles, placing it in the lower-traffic tier of Montana bridges. It is owned and maintained by Bureau of Indian Affairs.
The latest FHWA inspection records show a deck rating of 5/9, superstructure at 4/9, substructure at 2/9. The weakest component sits in critical condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 24.4 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How IRR ROUTE 46 compares
Live comparison across Montana.
Historical Sufficiency Rating
PlainBridge-computedFHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Structural Details
- Year Built
- 1963
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 7.7 m (25 ft)
- Deck Width
- 7.8 m (26 ft)
- Owner
- Bureau of Indian Affairs
- Avg Daily Traffic
- 100 vehicles/day
- Structure Number
- 0000C59205B0922
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in fair condition (5/9), with minor deterioration that may require routine maintenance.
- • The superstructure (beams and supports above the deck) rates poor at 4/9, advanced deterioration that should be prioritized for repair.
- • At 2/9, the substructure (piers and abutments) is in critical shape, with severe wear requiring urgent action.
How to read this record
IRR ROUTE 46 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 ROUTE 46 against other structures in Hill and across Montana. Montana 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 ROUTE 46?
IRR ROUTE 46 in Hill, Montana has a deck rating of 5/9, superstructure rating of 4/9, and substructure rating of 2/9 on the FHWA's 0–9 scale.
How often is IRR ROUTE 46 inspected?
IRR ROUTE 46'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. IRR ROUTE 46 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 ROUTE 46?
IRR ROUTE 46 has an NBI inventory load rating of 24.4 metric tons.
Who is responsible for maintaining IRR ROUTE 46?
IRR ROUTE 46 is owned and maintained by Bureau of Indian Affairs.
How old is IRR ROUTE 46 and does age affect safety?
IRR ROUTE 46 was built in 1963, making it 63 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.
Every figure on PlainBridge is rendered directly from federal source data, no number is typed in by an editor. This page draws directly on federal source data, no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.