IRR COUNTY ROAD
Carrying IRR COUNTY ROAD over BEAR CK
0.2 N. DUPREE, Ziebach, South Dakota
Data updated May 2026
FHWA NBI record, refreshed with each annual release.
Bridge Snapshot: IRR COUNTY ROAD
The IRR COUNTY ROAD bridge in Ziebach, South Dakota carries IRR COUNTY ROAD over BEAR CK. It was built in 1935, making it 91 years old today. The structure is built primarily of steel and spans 1 section, stretching 12.2 meters (40 feet) end to end. Daily traffic averages 10 vehicles, placing it in the lower-traffic tier of South Dakota bridges. It is owned and maintained by County Highway Agency.
The latest FHWA inspection records show a deck rating of 6/9, superstructure at 3/9, substructure at 3/9. The weakest component sits in poor condition. Because at least one major component scores 4 or lower, this bridge falls in FHWA's Poor condition category. That category is not a closure order. Its NBI inventory load rating is 2.7 metric tons.
Sourced from the FHWA National Bridge Inventory. See our methodology for refresh cadence and NBI release vintage.
How IRR COUNTY ROAD compares
Live comparison across South Dakota.
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 How the historical reference is calculated.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
- 1935
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 12.2 m (40 ft)
- Deck Width
- 4.9 m (16 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 10 vehicles/day
- Structure Number
- 000000069203288
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗Condition Analysis
- • At 6/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
- • The superstructure (beams and supports above the deck) is in poor condition (3/9), showing advanced deterioration that may require priority repair.
- • At 3/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.
How to read this record
IRR COUNTY ROAD 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 IRR COUNTY ROAD against other structures in Ziebach and across South Dakota. South Dakota 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 IRR COUNTY ROAD?
IRR COUNTY ROAD in Ziebach, South Dakota has a deck rating of 6/9, superstructure rating of 3/9, and substructure rating of 3/9 on the FHWA's 0–9 scale.
How often is IRR COUNTY ROAD inspected?
IRR COUNTY ROAD'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 10 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. IRR COUNTY ROAD 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 IRR COUNTY ROAD?
IRR COUNTY ROAD has an NBI inventory load rating of 2.7 metric tons.
Who is responsible for maintaining IRR COUNTY ROAD?
IRR COUNTY ROAD is owned and maintained by County Highway Agency.
How old is IRR COUNTY ROAD and does age affect safety?
IRR COUNTY ROAD was built in 1935, making it 91 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.