FHWA NBI 2024 Inspection record Public-domain dataset

IRR SD106

Carrying IRR SD106 over LITTLE MINNESOTA RV

3.2 W JCT SD 127, Roberts, South Dakota

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
39 t Inventory load rating

Bridge Snapshot: IRR SD106

The IRR SD106 bridge in Roberts, South Dakota carries IRR SD106 over LITTLE MINNESOTA RV. It was built in 1965, making it 61 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 36.3 meters (119 feet) end to end. Daily traffic averages 530 vehicles, placing it in the lower-traffic tier of South Dakota bridges. It is owned and maintained by State Highway Agency.

The latest FHWA inspection records show a deck rating of 6/9, 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 39.2 metric tons.

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

How IRR SD106 compares

▲ 6.7
Load rating vs South Dakota average (32.5 t)
Top 24%
Higher load rating than 76% of South Dakota bridges
157
Bridges in Roberts · 38 in Poor condition
IRR SD106 39.2 t
South Dakota average 32.5 t

Live comparison across South Dakota.

Historical Sufficiency Rating

PlainBridge-computed
92.4 / 100 - historical 80–100 band
Structural adequacy /55
55.0
Serviceability /30
25.0
Essentiality /15
12.8
Special reductions
−0.4

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 How the historical reference is calculated.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
6/9
Fair (5–6)
Superstructure
6/9
Fair (5–6)
Substructure
6/9
Fair (5–6)
Inventory Load Rating
39.2 t
NBI inventory level (metric tons)
Overall Condition
Fair

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

Structural Details

Year Built
1965
Material
Concrete Continuous
Number of Spans
3
Structure Length
36.3 m (119 ft)
Deck Width
10.5 m (34 ft)
Owner
State Highway Agency
Avg Daily Traffic
530 vehicles/day
Structure Number
000000055068060

Condition Analysis

  • At 6/9, 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.
  • At 6/9, the substructure (piers and abutments) shows fair condition, with minor wear flagged for upkeep.

How to read this record

This page shows what the last federal inspection recorded, not whether IRR SD106 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 IRR SD106 against other structures in Roberts 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 SD106?

IRR SD106 in Roberts, South Dakota has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.

How often is IRR SD106 inspected?

IRR SD106'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 530 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. IRR SD106 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 IRR SD106?

IRR SD106 has an NBI inventory load rating of 39.2 metric tons.

Who is responsible for maintaining IRR SD106?

IRR SD106 is owned and maintained by State Highway Agency.

How old is IRR SD106 and does age affect safety?

IRR SD106 was built in 1965, making it 61 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.