Total bridges
35
Public highway bridges in Kingsbury County
County profile · official public datasets
Kingsbury County, SD
35 public highway bridges tracked in the FHWA National Bridge Inventory: 17.1% rated Good, 54.3% Fair, 28.6% Poor.
- 35
- Public bridges
- 17.1%
- Good condition
- 28.6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Kingsbury County pairs a higher-than-median Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- 60th
- of 66 on Poor share
- 28.6%
- Poor-condition share
- 35
- public highway bridges
- 1964
- avg year built
Poor is an FHWA condition category from the lowest applicable component rating (4 or below), not a live crossing-safety or closure decision. Rankings cover counties with at least five public highway bridges.
Kingsbury County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Kingsbury County ranks #60 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 28.6%). Kingsbury County, South Dakota contains 35 public highway bridges. Roughly 17.1% are rated “Good,” 54.3% “Fair,” and 28.6% “Poor.” Poor means the lowest applicable deck, superstructure, substructure, or culvert rating is 4 or below on the 0–9 NBI scale. It is a condition category, not a live safety or closure decision.
Responsible agencies inspect covered bridges on risk-based intervals under current NBIS rules and submit inventory data to FHWA annually. The list below shows every NBI-tracked bridge in the county. Use the “Sort by” controls to change the ordering, and click any row for its reported inspection date, traffic count, and condition fields.
Source: FHWA National Bridge Inventory. See methodology for full definitions.
Good condition
17.1%
6 of 35 rated 7-9
Fair condition
54.3%
19 of 35 rated 5-6
Poor condition
28.6%
10 of 35 rated 4 or below
In-state Poor-share rank
#60 of 66
Among South Dakota counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 35 NBI-tracked bridges by lowest applicable component rating.
Good 17.1% (6)
Fair 54.3% (19)
Poor 28.6% (10)
Kingsbury County's Poor-condition bridges carry 1,449 vehicle crossings a day
That is 10.6% of the county's reported daily bridge traffic on 28.6% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 145 crossings a day against 308 for a Good-condition one. A Poor rating is a condition category, not a closure or a live safety judgement; it means the lowest applicable component rating is 4 or below.
Computed over the 35 of 35 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
57.1% of Kingsbury County's bridges have passed the 50-year mark
20 of the 35 bridges with a recorded construction year were built in 1974 or earlier. Age alone is not a defect: a well-maintained older bridge can rate Good, and 17.1% of this county's inventory does. Even so, this older cohort is the population from which future Poor ratings are drawn, which is why the age profile below matters alongside the condition split above.
Cutoff derives from the 2024 release year minus a 50-year design life. Source: FHWA National Bridge Inventory, 2024 release.
One structure carries 63% of the county's Poor-condition bridge traffic
208TH ST over SOUTH FORK PEARL CK, built 1933, carries 913 vehicles a day, the most of any Poor-rated structure here. The county's Poor-condition exposure is concentrated rather than evenly spread, so the 10-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 1,449 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Kingsbury County's bridges were built
35 bridges with a recorded construction year, grouped by decade
- 1920s 2
1920–1929
2 bridges
- 1930s
1930–1939
8 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s 2
1950–1959
2 bridges
- 1960s
1960–1969
6 bridges
- 1970s 3
1970–1979
3 bridges
- 1980s
1980–1989
9 bridges
- 1990s 1
1990–1999
1 bridges
- 2020s 2
2020–2029
2 bridges
What this shows Construction peaked in the 1980s, when 9 of the county's bridges still in the inventory were built, which is 25.7% of those with a recorded year. That cohort is now 35 to 44 years old in the 2024 inventory. Its average build year is 1964, 11 years older than the South Dakota average of 1975.
How Kingsbury County compares with South Dakota's closest counties by inventory size
The 5 South Dakota counties nearest Kingsbury County in number of bridges, with their condition splits. Its 28.6% Poor share is the 5th-lowest of these 6. Its average build year of 1964 against a peer-group mean of 1971 is 7 years older.
Showing the 5 closest of 65 South Dakota counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Jones County | 37 | 13.5% | 81.1% | 5.4% | 1965 |
| Stanley County | 37 | 37.8% | 48.6% | 13.5% | 1969 |
| Jerauld County | 35 | 20% | 54.3% | 25.7% | 1967 |
| Kingsbury County (this page) | 35 | 17.1% | 54.3% | 28.6% | 1964 |
| Day County | 34 | 35.3% | 29.4% | 35.3% | 1963 |
| Oglala Lakota County | 34 | 55.9% | 38.2% | 5.9% | 1992 |
Each share is of that county's own total tracked bridges; peers are the counties with 5 or more bridges whose inventory size is closest to Kingsbury County's. Source: FHWA National Bridge Inventory, 2024 release.
Nationwide counties with similar inventory size or average build year
Two NBI-derived peer sets for Kingsbury County, both outside South Dakota so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside SD (35 bridges here).
- Seminole County, GA · 35 bridges
- Manistee County, MI · 35 bridges
- Toole County, MT · 35 bridges
- Ransom County, ND · 35 bridges
Similar average build year
Nearest mean year-built outside SD (1964 here).
- Bergen County, NJ · avg 1964 · 577 bridges
- Morris County, NJ · avg 1964 · 508 bridges
- Baltimore city County, MD · avg 1964 · 374 bridges
- Ross County, OH · avg 1964 · 356 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (6)
204 ST
GoodOver: SOUTH FORK PEARL CK
4 N & 0.5 E IROQUOIS, Kingsbury, SD
Built 1987 Load: 19.6 t ADT: 75
441ST AVENUE
GoodOver: CK
1W 2.5S LK PRESTON, Kingsbury, SD
Built 1986 Load: 24.5 t ADT: 200
425TH AVE
GoodOver: REDSTONE CK
0.9 S MANCHESTER, Kingsbury, SD
Built 1989 Load: 28.8 t ADT: 150
198TH STREET
GoodOver: CK
2 N & 3.4 E BADGER, Kingsbury, SD
Built 2023 Load: 37.8 t ADT: 7
197TH ST
GoodOver: MARSH CK
3 N & 0.2 E BANCROFT, Kingsbury, SD
Built 1992 Load: 46.3 t ADT: 75
SD025
GoodOver: CK
2.1 N JCT US 14, Kingsbury, SD
Built 2023 Load: 48.4 t ADT: 1,339
Read our methodology - how this data is sourced, computed, and verified.
Related
Data sourced from official public datasets. See our methodology for details. Retrieved and formatted by PlainBridges
Every figure on PlainBridges 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. NBI condition categories reflect the latest reported inventory record, not a live safety, closure, or travel decision.