FHWA NBI 2024 Inspection record Public-domain dataset

S 41

Carrying S 41 over BEAVERHEAD RIVER

12M SW TWIN BRIDGES, Madison, Montana

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
25 t Inventory load rating

Bridge Snapshot: S 41

The S 41 bridge in Madison, Montana carries S 41 over BEAVERHEAD RIVER. It was built in 1949, making it 77 years old today. The structure is built primarily of steel and spans 2 sections, stretching 46.6 meters (153 feet) end to end. Daily traffic averages 2,326 vehicles, placing it in the moderately-trafficked tier of Montana bridges. It is owned and maintained by State Highway Agency.

The latest FHWA inspection records show a deck rating of 5/9, superstructure at 6/9, substructure at 6/9. The weakest component sits in fair condition. No reported major component scores in the Poor range under the current federal condition thresholds. Its NBI inventory load rating is 24.5 metric tons.

Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.

How S 41 compares

▼ 6.2
Load rating vs Montana average (30.7 t)
Bottom 28%
Lower load rating than 72% of Montana bridges
84
Bridges in Madison · 11 in Poor condition
S 41 24.5 t
Montana average 30.7 t

Live comparison across Montana.

Historical Sufficiency Rating

PlainBridge-computed
59.6 / 100 - historical 50–79.9 band
Structural adequacy /55
47.8
Serviceability /30
18.9
Essentiality /15
0.0
Special reductions
−7.0

FHWA discontinued this calculated item; it does not determine current condition, funding eligibility, posting, or closure. How the historical reference is calculated.

Condition Ratings

Deck
5/9
Fair (5–6)
Superstructure
6/9
Fair (5–6)
Substructure
6/9
Fair (5–6)
Inventory Load Rating
24.5 t
NBI inventory level (metric tons)
Overall Condition
Fair

Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.

Structural Details

Year Built
1949
Material
Steel
Number of Spans
2
Structure Length
46.6 m (153 ft)
Deck Width
9.7 m (32 ft)
Owner
State Highway Agency
Avg Daily Traffic
2,326 vehicles/day
Structure Number
P00049014+06711

Condition Analysis

  • At 5/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
  • At 6/9, the superstructure (beams and supports above the deck) shows fair condition, with minor wear flagged for upkeep.
  • The substructure (piers and abutments) is in fair condition (6/9), with minor deterioration that may require routine maintenance.

How to read this record

This page shows what the last federal inspection recorded, not whether S 41 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 S 41 against other structures in Madison 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 S 41?

S 41 in Madison, Montana has a deck rating of 5/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.

How often is S 41 inspected?

S 41'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 2,326 vehicles per day.

What does “structurally deficient” mean in older bridge reports?

FHWA retired that reported status beginning with the 2018 archive. S 41 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 S 41?

S 41 has an NBI inventory load rating of 24.5 metric tons.

Who is responsible for maintaining S 41?

S 41 is owned and maintained by State Highway Agency.

How old is S 41 and does age affect safety?

S 41 was built in 1949, making it 77 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.

Data sourced from the Federal Highway Administration National Bridge Inventory. See our methodology for details. Retrieved and formatted by PlainBridges

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.