30830 405TH AVE
Carrying 30830 405TH AVE over Trib. to Choteau Creek
6.3 S 1 W AVON, Bon Homme, South Dakota
Inventory: FHWA NBI 2024 · last ETL August 2026
FHWA NBI record, refreshed with each annual release.
30830 405TH AVE in Bon Homme, South Dakota sits above 8% of rated South Dakota bridges on inventory load rating (13 t), while its 1935 build year is earlier than 68% of Bon Homme's recorded-year cohort (126 bridges).
30830 405TH AVE in Bon Homme, South Dakota is rated Poor in the FHWA's 2024 National Bridge Inventory. Built in 1935, it carries 3 rated components on the inspecting agency's 0-9 scale, and its weakest reported component scores 4. The lowest applicable rating sets the federal condition category, so this Poor result describes the weakest reported component rather than the structure as a whole. No NBI category is a closure decision or a live crossing-safety verdict.
NBI record plate
Structure SD:000000005040173
PRE-1950 · STEEL · SINGLE-SPAN · DECK-LED · LOCAL-ADT · LIGHT-LOAD · CAT-POOR
- PRE-1950 Pre-1950
- STEEL Steel
- SINGLE-SPAN Single span
- DECK-LED Deck-led
- LOCAL-ADT Local ADT
- LIGHT-LOAD Light load
- CAT-POOR Poor
Inspection-sheet codes from this record’s year, material family, spans, controlling component, ADT, inventory load, and NBI category, not a live closure verdict.
Bridge Snapshot: 30830 405TH AVE
The 30830 405TH AVE bridge in Bon Homme, South Dakota carries 30830 405TH AVE over Trib. to Choteau Creek. It was built in 1935, making it 91 years old today. The structure is built primarily of steel and spans 1 section, stretching 10.4 meters (34 feet) end to end. Daily traffic averages 60 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 4/9, superstructure at 5/9, substructure at 7/9. 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.
How 30830 405TH AVE compares
Age against the county: built in 1935, earlier than 86 of Bon Homme's 126 bridges with a recorded construction year (68%), against a county median build year of 1964. Age is not a defect on its own, but it is the population from which future Poor ratings are drawn.
Live comparison across South Dakota bridges with a recorded inventory load rating (5,886 of 5,887 rated).
30830 405TH AVE vs every rated South Dakota bridge
Inventory load rating (metric tons), FHWA NBI, this state
13 Top 92% higher than 8% of 5,886 bridges
rated South Dakota bridges, bucketed by value
Each bar is a band; taller bars hold more bridges. The dashed line + filled bar mark this entry. Hover or tap any bar for its full count and share, and where it sits relative to this entry.
Source FHWA National Bridge Inventory · August 2026
Condition Ratings
Full 0–9 scale + sufficiency-rating breakdown: how condition ratings work.
Reported 0–9 component ratings from the FHWA NBI. The highlighted component is the lowest reported input to this record’s current condition category; it is not a closure or live crossing-safety decision.
Bon Homme inventory by recorded NBI category
Exclusive Good/Fair/Poor bands across all 126 bridges in this county. Orthogonal to this structure's component profile above: a county catalog share, not a live crossing-safety verdict.
Structural Details
- Year Built
- 1935
- Material
- Steel
- Number of Spans
- 1
- Structure Length
- 10.4 m (34 ft)
- Deck Width
- 6.2 m (20 ft)
- Owner
- County Highway Agency
- Avg Daily Traffic
- 60 vehicles/day
- Structure Number
- 000000005040173
Condition Analysis
- • The deck (driving surface) is in poor condition (4/9), showing advanced deterioration on the inspecting agency's 0-9 scale.
- • The superstructure (beams and supports above the deck) rates fair at 5/9, minor deterioration that routine maintenance should address.
- • At 7/9, the substructure (piers and abutments) is in good shape and shows no significant wear.
Location
Data Source
FHWA National Bridge Inventory (NBI).
FHWA NBI Program ↗How to read this record
30830 405TH AVE 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 30830 405TH AVE against other structures in Bon Homme 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 30830 405TH AVE?
30830 405TH AVE in Bon Homme, South Dakota has a deck rating of 4/9, superstructure rating of 5/9, and substructure rating of 7/9 on the FHWA's 0–9 scale.
How often is 30830 405TH AVE inspected?
30830 405TH AVE'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 60 vehicles per day.
What does “structurally deficient” mean in older bridge reports?
FHWA retired that reported status beginning with the 2018 archive. 30830 405TH AVE 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 30830 405TH AVE?
30830 405TH AVE has an NBI inventory load rating of 12.5 metric tons.
Who is responsible for maintaining 30830 405TH AVE?
30830 405TH AVE is owned and maintained by County Highway Agency.
How old is 30830 405TH AVE and does age affect safety?
30830 405TH AVE 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.
Share this inspection record
Send this source-bounded record or download its data card. An NBI condition category is not a closure or live crossing-safety verdict.
Every figure on PlainBridges is rendered directly from federal source data, no number is typed in by an editor. Component ratings, ADT, and condition category on this page are copied from the NBI record for this structure; no figure is typed in by an editor. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 2024 NBI release. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.