Total bridges
38
Public highway bridges in Brule County
County profile · official public datasets
Brule County, SD
38 public highway bridges tracked in the FHWA National Bridge Inventory: 34.2% rated Good, 63.2% Fair, 2.6% Poor.
- 38
- Public bridges
- 34.2%
- Good condition
- 2.6%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Brule County pairs a top-10% lowest Poor-condition share among rated counties in the state with an older average build year than the state inventory.
- Top 9%
- lowest Poor share in state
- 2.6%
- Poor-condition share
- 38
- public highway bridges
- 1966
- 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.
Brule County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Brule County ranks #6 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 2.6%). Brule County, South Dakota contains 38 public highway bridges. Roughly 34.2% are rated “Good,” 63.2% “Fair,” and 2.6% “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
34.2%
13 of 38 rated 7-9
Fair condition
63.2%
24 of 38 rated 5-6
Poor condition
2.6%
1 of 38 rated 4 or below
In-state Poor-share rank
#6 of 66
Among South Dakota counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 38 NBI-tracked bridges by lowest applicable component rating.
Good 34.2% (13)
Fair 63.2% (24)
Poor 2.6% (1)
Brule County's Poor-condition bridges carry 4,554 vehicle crossings a day
That is 6.3% of the county's reported daily bridge traffic on 2.6% of its bridges: Poor-condition structures carry more traffic than their share of the inventory. Each Poor bridge averages 4,554 crossings a day against 3,378 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 38 of 38 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
86.8% of Brule County's bridges have passed the 50-year mark
33 of the 38 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 34.2% 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 100% of the county's Poor-condition bridge traffic
SD050 over R&W RR, built 1952, carries 4,554 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 1-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 4,554 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Brule County's bridges were built
38 bridges with a recorded construction year, grouped by decade
- 1930s 1
1930–1939
1 bridges
- 1940s 2
1940–1949
2 bridges
- 1950s
1950–1959
10 bridges
- 1960s
1960–1969
15 bridges
- 1970s 5
1970–1979
5 bridges
- 1990s 2
1990–1999
2 bridges
- 2000s 3
2000–2009
3 bridges
What this shows Construction peaked in the 1960s, when 15 of the county's bridges still in the inventory were built, which is 39.5% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year is 1966, 9 years older than the South Dakota average of 1975.
How Brule County compares with South Dakota's closest counties by inventory size
The 5 South Dakota counties nearest Brule County in number of bridges, with their condition splits. Its 2.6% Poor share is the 1st-lowest of these 6. Its average build year of 1966 against a peer-group mean of 1969 is in line with the group.
Showing the 5 closest of 65 South Dakota counties eligible for comparison.
| County | Bridges | Good | Fair | Poor | Avg. built |
|---|---|---|---|---|---|
| Hughes County | 40 | 40% | 37.5% | 22.5% | 1978 |
| Marshall County | 39 | 15.4% | 51.3% | 33.3% | 1965 |
| Brule County (this page) | 38 | 34.2% | 63.2% | 2.6% | 1966 |
| 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 |
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 Brule 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 Brule County, both outside South Dakota so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside SD (38 bridges here).
- Peach County, GA · 38 bridges
- Chowan County, NC · 38 bridges
- Kinney County, TX · 38 bridges
- Lipscomb County, TX · 38 bridges
Similar average build year
Nearest mean year-built outside SD (1966 here).
- Butler County, KS · avg 1966 · 591 bridges
- Grafton County, NH · avg 1966 · 544 bridges
- Queens County, NY · avg 1966 · 514 bridges
- Lehigh County, PA · avg 1966 · 381 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Good-condition bridges (13)
I090
GoodOver: MAIN ST R&W RR
CHAMBERLAIN INTERCHANGE, Brule, SD
Built 1974 Load: 26.5 t ADT: 7,260
365 AVE
GoodOver: I090
2.0 W SD 45S INTERCH, Brule, SD
Built 1965 Load: 30.2 t ADT: 41
I090 W
GoodOver: 356 AVE
5.5 E SD 50 INTERCH, Brule, SD
Built 1964 Load: 31.8 t ADT: 4,965
I090 E
GoodOver: 356 AVE
5.5 E SD 50 INTERCH, Brule, SD
Built 1964 Load: 31.8 t ADT: 4,965
I090 WB OFF RAMP
GoodOver: I090
0.9 SE CHAMB INTERCHANGE, Brule, SD
Built 1974 Load: 33.5 t ADT: 4
I090 W
GoodOver: 251 ST
2.9 W SD 45 N INTERCH, Brule, SD
Built 2006 Load: 33.5 t ADT: 4,965
I090 E
GoodOver: 251 ST
2.9 W SD 45 N INTERCH, Brule, SD
Built 2007 Load: 33.5 t ADT: 4,965
SD050
GoodOver: NELSON CK
4.6 S I 90 INTERCH, Brule, SD
Built 1970 Load: 41.8 t ADT: 233
SD050
GoodOver: AMERICAN CK
0.5 N JCT I 90 LOOP, Brule, SD
Built 1999 Load: 47.1 t ADT: 3,199
SD050
GoodOver: I090
E CHAMBERLAIN INTERCHANGE, Brule, SD
Built 1964 Load: 47.2 t ADT: 3,639
I090
GoodOver: CK
0.8 W SD 45 S INTERCH, Brule, SD
Built 1964 Load: 49.3 t ADT: 7,670
SD045
GoodOver: CK
2.6 S I 90 INTERCH, Brule, SD
Built 1949 Load: 73.3 t ADT: 1,047
SD045
GoodOver: CK
1.9 S I 90 INTERCH, Brule, SD
Built 1948 Load: 79.9 t ADT: 963
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.