DUNN LN
Carrying DUNN LN over BOULDER RIVER 028
20M SE BOULDER, Jefferson, Montana
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: DUNN LN
The DUNN LN bridge in Jefferson, Montana carries DUNN LN over BOULDER RIVER 028. It was built in 2015, making it 11 years old today. The structure is built primarily of concrete and spans 1 section, stretching 26.1 meters (86 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 County Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 7/9, substructure at 7/9. The weakest component sits in good condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 37.2 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How DUNN LN 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 How the historical reference is calculated.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
- 2015
- Material
- Concrete
- Number of Spans
- 1
- Structure Length
- 26.1 m (86 ft)
- Deck Width
- 8.0 m (26 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 100 vehicles/day
- Structure Number
- L22313000+06001
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) rates good at 7/9, with no significant deterioration on file.
- • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
- • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.
How to read this record
This page shows what the last federal inspection recorded, not whether DUNN LN 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 DUNN LN against other structures in Jefferson 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 DUNN LN?
DUNN LN in Jefferson, Montana has a deck rating of 7/9, superstructure rating of 7/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is DUNN LN inspected?
DUNN LN'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. DUNN LN is currently shown as Good condition from its component ratings; that category is not a live closure or safety decision.
What is the inventory load rating for DUNN LN?
DUNN LN has an NBI inventory load rating of 37.2 metric tons.
Who is responsible for maintaining DUNN LN?
DUNN LN is owned and maintained by County Highway Agency.
How old is DUNN LN and does age affect safety?
DUNN LN was built in 2015, making it 11 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.