STH 243
Carrying STH 243 over ST CROIX RIVER 06
AT MINNESOTA STATE LINE, Polk, Wisconsin
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: STH 243
The STH 243 bridge in Polk, Wisconsin carries STH 243 over ST CROIX RIVER 06. It was built in 1953, making it 73 years old today. It was last reconstructed in 1980, extending its service life. The structure is built primarily of steel and spans 5 sections, stretching 205.4 meters (674 feet) end to end. Daily traffic averages 5,686 vehicles, placing it in the moderately-trafficked tier of Wisconsin bridges. It is owned and maintained by State Highway Agency.
The latest FHWA inspection records show a deck rating of 4/9, superstructure at 5/9, substructure at 6/9. The weakest component sits in poor condition. At least one major component here scores 4 or below, which produces a Poor condition classification under FHWA's current reporting rules. Its NBI inventory load rating is 19.4 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How STH 243 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 How the historical reference is calculated.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
- 1953
- Last Reconstructed
- 1980
- Material
- Steel
- Number of Spans
- 5
- Structure Length
- 205.4 m (674 ft)
- Deck Width
- 10.4 m (34 ft)
- Owner
- State Highway Agency
- Avg Daily Traffic
- 5,686 vehicles/day
- Structure Number
- B48022400000000
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration that may require priority repair.
- • The superstructure (beams and supports above the deck) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • The substructure (piers and abutments) rates fair at 6/9, minor deterioration that routine maintenance should address.
How to read this record
STH 243 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 STH 243 against other structures in Polk 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 STH 243?
STH 243 in Polk, Wisconsin has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.
How often is STH 243 inspected?
STH 243'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 5,686 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. STH 243 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 STH 243?
STH 243 has an NBI inventory load rating of 19.4 metric tons.
Who is responsible for maintaining STH 243?
STH 243 is owned and maintained by State Highway Agency.
How old is STH 243 and does age affect safety?
STH 243 was built in 1953, making it 73 years old and last reconstructed in 1980.
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.