FHWA NBI 2024 Inspection record Public-domain dataset

IRR US012

Carrying IRR US012 over BR SNAKE CK

1.7 NW JCT SD 20, Corson, South Dakota

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Poor
25 t Inventory load rating

Bridge Snapshot: IRR US012

The IRR US012 bridge in Corson, South Dakota carries IRR US012 over BR SNAKE CK. It was built in 1965, making it 61 years old today. The structure is built primarily of concrete continuous and spans 2 sections, stretching 6.5 meters (21 feet) end to end. Daily traffic averages 1,102 vehicles, placing it in the moderately-trafficked tier of South Dakota bridges. It is owned and maintained by State Highway Agency.

The latest FHWA inspection records show culvert at 4/9. 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 24.9 metric tons.

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

How IRR US012 compares

▼ 7.6
Load rating vs South Dakota average (32.5 t)
Bottom 48%
Lower load rating than 52% of South Dakota bridges
49
Bridges in Corson · 5 in Poor condition
IRR US012 24.9 t
South Dakota average 32.5 t

Live comparison across South Dakota.

Historical Sufficiency Rating

PlainBridge-computed
61.6 / 100 - historical 50–79.9 band
Structural adequacy /55
23.3
Serviceability /30
27.0
Essentiality /15
12.3
Special reductions
−1.0

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 How the historical reference is calculated.

Condition Ratings

Culvert
4/9
Poor (1–4)
Inventory Load Rating
24.9 t
NBI inventory level (metric tons)
Overall Condition
Poor

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

Structural Details

Year Built
1965
Material
Concrete Continuous
Number of Spans
2
Structure Length
6.5 m (21 ft)
Owner
State Highway Agency
Avg Daily Traffic
1,102 vehicles/day
Structure Number
000000016687258

How to read this record

IRR US012 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 US012 against other structures in Corson 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 US012?

IRR US012 in Corson, South Dakota on the FHWA's 0–9 scale.

How often is IRR US012 inspected?

IRR US012'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 1,102 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. IRR US012 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 US012?

IRR US012 has an NBI inventory load rating of 24.9 metric tons.

Who is responsible for maintaining IRR US012?

IRR US012 is owned and maintained by State Highway Agency.

How old is IRR US012 and does age affect safety?

IRR US012 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.