FHWA NBI 2024 Inspection record Public-domain dataset

29470 381st Avenue

Carrying 29470 381st Avenue over Creek

2.7S & 1.0W of Lake Andes, Charles Mix, South Dakota

Data updated May 2026

FHWA NBI record, refreshed with each annual release.

Poor
18 t Inventory load rating

Bridge Snapshot: 29470 381st Avenue

The 29470 381st Avenue bridge in Charles Mix, South Dakota carries 29470 381st Avenue over Creek. It was built in 1979, making it 47 years old today. The structure is built primarily of prestressed concrete and spans 1 section, stretching 15.5 meters (51 feet) end to end. Daily traffic averages 48 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 6/9, substructure at 3/9. The weakest component sits in poor condition. A component scored 4 or below, placing this bridge in the federal Poor condition category rather than declaring it unsafe or closed. Its NBI inventory load rating is 18.4 metric tons.

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

How 29470 381st Avenue compares

▼ 14.1
Load rating vs South Dakota average (32.5 t)
Bottom 15%
Lower load rating than 85% of South Dakota bridges
103
Bridges in Charles Mix · 24 in Poor condition
29470 381st Avenue 18.4 t
South Dakota average 32.5 t

Live comparison across South Dakota.

Historical Sufficiency Rating

PlainBridge-computed
39.0 / 100 - historical 20–49.9 band
Structural adequacy /55
0.0
Serviceability /30
24.0
Essentiality /15
15.0
Special reductions
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 How the historical reference is calculated.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
6/9
Fair (5–6)
Superstructure
6/9
Fair (5–6)
Substructure
3/9
Poor (1–4)
Inventory Load Rating
18.4 t
NBI inventory level (metric tons)
Overall Condition
Poor

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

Structural Details

Year Built
1979
Material
Prestressed Concrete
Number of Spans
1
Structure Length
15.5 m (51 ft)
Deck Width
6.1 m (20 ft)
Owner
County Highway Agency
Avg Daily Traffic
48 vehicles/day
Structure Number
000000012370267

Condition Analysis

  • The deck (driving surface) rates fair at 6/9, minor deterioration that routine maintenance should address.
  • The superstructure (beams and supports above the deck) is in fair condition (6/9), with minor deterioration that may require routine maintenance.
  • At 3/9, the substructure (piers and abutments) is in poor shape, with advanced wear flagged for priority repair.

How to read this record

29470 381st Avenue 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 29470 381st Avenue against other structures in Charles Mix 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 29470 381st Avenue?

29470 381st Avenue in Charles Mix, South Dakota has a deck rating of 6/9, superstructure rating of 6/9, and substructure rating of 3/9 on the FHWA's 0–9 scale.

How often is 29470 381st Avenue inspected?

29470 381st Avenue'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 48 vehicles per day.

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

FHWA retired that reported status beginning with the 2018 archive. 29470 381st Avenue 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 29470 381st Avenue?

29470 381st Avenue has an NBI inventory load rating of 18.4 metric tons.

Who is responsible for maintaining 29470 381st Avenue?

29470 381st Avenue is owned and maintained by County Highway Agency.

How old is 29470 381st Avenue and does age affect safety?

29470 381st Avenue was built in 1979, making it 47 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.