FHWA NBI 2024 Inspection record Public-domain dataset

IRON LIGHTENING RD

Carrying IRON LIGHTENING RD over BEAR CK

0.2 S& 1.5 W RED ELM, Ziebach, South Dakota

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Fair
22 t Inventory load rating

Bridge Snapshot: IRON LIGHTENING RD

The IRON LIGHTENING RD bridge in Ziebach, South Dakota carries IRON LIGHTENING RD over BEAR CK. It was built in 1954, making it 72 years old today. The structure is built primarily of concrete continuous and spans 3 sections, stretching 22.6 meters (74 feet) end to end. Daily traffic averages 35 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 5/9, superstructure at 7/9, 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 21.9 metric tons.

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

How IRON LIGHTENING RD compares

▼ 10.6
Load rating vs South Dakota average (32.5 t)
Bottom 27%
Lower load rating than 73% of South Dakota bridges
30
Bridges in Ziebach · 3 in Poor condition
IRON LIGHTENING RD 21.9 t
South Dakota average 32.5 t

Live comparison across South Dakota.

Historical Sufficiency Rating

PlainBridge-computed
81.8 / 100 - historical 80–100 band
Structural adequacy /55
43.9
Serviceability /30
26.0
Essentiality /15
14.9
Special reductions
−3.0

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 How the historical reference is calculated.

Condition Ratings

Deck
5/9
Fair (5–6)
Superstructure
7/9
Good (7–9)
Substructure
6/9
Fair (5–6)
Inventory Load Rating
21.9 t
NBI inventory level (metric tons)
Overall Condition
Fair

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

Structural Details

Year Built
1954
Material
Concrete Continuous
Number of Spans
3
Structure Length
22.6 m (74 ft)
Deck Width
8.6 m (28 ft)
Owner
County Highway Agency
Avg Daily Traffic
35 vehicles/day
Structure Number
000000069100288

Condition Analysis

  • At 5/9, the deck (driving surface) shows fair condition, with minor wear flagged for upkeep.
  • At 7/9, the superstructure (beams and supports above the deck) is in good shape and shows no significant wear.
  • 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 IRON LIGHTENING RD 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 IRON LIGHTENING RD 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 IRON LIGHTENING RD?

IRON LIGHTENING RD in Ziebach, South Dakota has a deck rating of 5/9, superstructure rating of 7/9, and substructure rating of 6/9 on the FHWA's 0–9 scale.

How often is IRON LIGHTENING RD inspected?

IRON LIGHTENING RD'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 35 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. IRON LIGHTENING RD 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 IRON LIGHTENING RD?

IRON LIGHTENING RD has an NBI inventory load rating of 21.9 metric tons.

Who is responsible for maintaining IRON LIGHTENING RD?

IRON LIGHTENING RD is owned and maintained by County Highway Agency.

How old is IRON LIGHTENING RD and does age affect safety?

IRON LIGHTENING RD was built in 1954, making it 72 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.