IH 39SB
Carrying IH 39SB over BULL JUNIOR CREEK
7.3M S JCT STH 29 TO E, Marathon, Wisconsin
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: IH 39SB
The IH 39SB bridge in Marathon, Wisconsin carries IH 39SB over BULL JUNIOR CREEK. It was built in 2009, making it 17 years old today. The structure is built primarily of prestressed concrete continuous and spans 3 sections, stretching 27.8 meters (91 feet) end to end. Daily traffic averages 29,800 vehicles, placing it in the heavily-trafficked tier of Wisconsin bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 7/9, superstructure at 8/9, substructure at 8/9. The weakest component sits in good condition. All reported major components score above the Poor range. Its NBI inventory load rating is 50.2 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How IH 39SB compares
Live comparison across Wisconsin.
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 How the historical reference is calculated.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
- 2009
- Material
- Prestressed Concrete Continuous
- Number of Spans
- 3
- Structure Length
- 27.8 m (91 ft)
- Deck Width
- 22.9 m (75 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 29,800 vehicles/day
- Structure Number
- B37041800000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 7/9, the deck (driving surface) is in good shape and shows no significant wear.
- • The superstructure (beams and supports above the deck) rates good at 8/9, with no significant deterioration on file.
- • The substructure (piers and abutments) rates good at 8/9, with no significant deterioration on file.
How to read this record
This page shows what the last federal inspection recorded, not whether IH 39SB 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 IH 39SB against other structures in Marathon and across Wisconsin. Wisconsin 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 IH 39SB?
IH 39SB in Marathon, Wisconsin has a deck rating of 7/9, superstructure rating of 8/9, and substructure rating of 8/9 on the FHWA's 0–9 scale.
How often is IH 39SB inspected?
IH 39SB'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 29,800 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IH 39SB 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 IH 39SB?
IH 39SB has an NBI inventory load rating of 50.2 metric tons.
Who is responsible for maintaining IH 39SB?
IH 39SB is owned and maintained by State Highway Agency.
How old is IH 39SB and does age affect safety?
IH 39SB was built in 2009, making it 17 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.