RD 231
Carrying RD 231 over W FISHER CR
THUNDER MTN RANCH, Lincoln, Montana
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: RD 231
The RD 231 bridge in Lincoln, Montana carries RD 231 over W FISHER CR. It was built in 1954, making it 72 years old today. The structure is built primarily of steel and spans 1 section, stretching 18.4 meters (60 feet) end to end. Daily traffic averages 50 vehicles, placing it in the lower-traffic tier of Montana bridges. It is owned and maintained by U.S. Forest Service.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 7/9, substructure at 5/9. The weakest component sits in fair condition. None of this bridge's reported major components fall into the Poor condition range. Its NBI inventory load rating is 20.4 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How RD 231 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 How the historical reference is calculated.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
- 1954
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 18.4 m (60 ft)
- Deck Width
- 4.7 m (15 ft)
- Owner
- U.S. Forest Service
- Avg Daily Traffic
- 50 vehicles/day
- Structure Number
- 011405000000219
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates fair at 6/9, minor deterioration that routine maintenance should address.
- • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • At 5/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.
How to read this record
This page shows what the last federal inspection recorded, not whether RD 231 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 RD 231 against other structures in Lincoln 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 RD 231?
RD 231 in Lincoln, Montana has a deck rating of 6/9, superstructure rating of 7/9, and substructure rating of 5/9 on the FHWA's 0–9 scale.
How often is RD 231 inspected?
RD 231'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 50 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. RD 231 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 RD 231?
RD 231 has an NBI inventory load rating of 20.4 metric tons.
Who is responsible for maintaining RD 231?
RD 231 is owned and maintained by U.S. Forest Service.
How old is RD 231 and does age affect safety?
RD 231 was built in 1954, making it 72 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.