Total bridges
123
Public highway bridges in Davison County
County profile · official public datasets
Davison County, SD
123 public highway bridges tracked in the FHWA National Bridge Inventory: 34.1% rated Good, 48.8% Fair, 17.1% Poor.
- 123
- Public bridges
- 34.1%
- Good condition
- 17.1%
- Poor condition
The verdict
According to the Federal Highway Administration's 2024 National Bridge Inventory.
Davison County posts a higher-than-median Poor-condition share among rated counties in the state across mid-size county bridge inventory.
- 42nd
- of 66 on Poor share
- 17.1%
- Poor-condition share
- 123
- public highway bridges
- 1973
- 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.
Davison County Bridge Snapshot
According to the Federal Highway Administration's 2024 National Bridge Inventory, Davison County ranks #42 of 66 South Dakota counties with at least 5 public highway bridges on Poor-condition share (lower share ranks better; currently 17.1%). Davison County, South Dakota contains 123 public highway bridges. Roughly 34.1% are rated “Good,” 48.8% “Fair,” and 17.1% “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
34.1%
42 of 123 rated 7-9
Fair condition
48.8%
60 of 123 rated 5-6
Poor condition
17.1%
21 of 123 rated 4 or below
In-state Poor-share rank
#42 of 66
Among South Dakota counties with 5+ bridges, lower share ranks better
Condition distribution
Share of 123 NBI-tracked bridges by lowest applicable component rating.
Good 34.1% (42)
Fair 48.8% (60)
Poor 17.1% (21)
Davison County's Poor-condition bridges carry 1,728 vehicle crossings a day
That is 1.1% of the county's reported daily bridge traffic on 17.1% of its bridges: Poor-condition structures carry less traffic than their share of the inventory. Each Poor bridge averages 82 crossings a day against 1,429 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 123 of 123 bridges in this county that report an average daily traffic count. Source: FHWA National Bridge Inventory, 2024 release.
54.5% of Davison County's bridges have passed the 50-year mark
67 of the 123 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 34.1% 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 22.6% of the county's Poor-condition bridge traffic
403RD AVENUE over FIRESTEEL CK, built 1910, carries 390 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 21-bridge count understates how much of the daily burden sits on a single crossing.
Share is of the 1,728 daily crossings on Poor-rated bridges that report a traffic count. Source: FHWA National Bridge Inventory, 2024 release.
When Davison County's bridges were built
123 bridges with a recorded construction year, grouped by decade
- 1910s 4
1910–1919
4 bridges
- 1920s 6
1920–1929
6 bridges
- 1930s 8
1930–1939
8 bridges
- 1940s 8
1940–1949
8 bridges
- 1950s 3
1950–1959
3 bridges
- 1960s
1960–1969
30 bridges
- 1970s
1970–1979
18 bridges
- 1980s 9
1980–1989
9 bridges
- 1990s 8
1990–1999
8 bridges
- 2000s
2000–2009
19 bridges
- 2010s 4
2010–2019
4 bridges
- 2020s 6
2020–2029
6 bridges
What this shows Construction peaked in the 1960s, when 30 of the county's bridges still in the inventory were built, which is 24.4% of those with a recorded year. That cohort is now 55 to 64 years old in the 2024 inventory. Its average build year (1973) matches the South Dakota average (1975).
How Davison County compares with South Dakota's closest counties by inventory size
The 5 South Dakota counties nearest Davison County in number of bridges, with their condition splits. Its 17.1% Poor share is the 4th-lowest of these 6. Its average build year of 1973 against a peer-group mean of 1971 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 |
|---|---|---|---|---|---|
| Butte County | 143 | 30.8% | 57.3% | 11.9% | 1976 |
| Lawrence County | 136 | 36% | 51.5% | 12.5% | 1980 |
| Bon Homme County | 126 | 21.4% | 50.8% | 27.8% | 1961 |
| Hand County | 126 | 24.6% | 46% | 29.4% | 1961 |
| Davison County (this page) | 123 | 34.1% | 48.8% | 17.1% | 1973 |
| Lyman County | 114 | 40.4% | 50% | 9.6% | 1975 |
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 Davison 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 Davison County, both outside South Dakota so the neighborhoods are not the same-state size table above.
Similar inventory size
Nearest county inventories outside SD (123 bridges here).
- Jackson County, GA · 123 bridges
- Crawford County, IN · 123 bridges
- Hickman County, KY · 123 bridges
- Bladen County, NC · 123 bridges
Similar average build year
Nearest mean year-built outside SD (1973 here).
- Jefferson County, AL · avg 1973 · 1,068 bridges
- Erie County, NY · avg 1973 · 906 bridges
- Davidson County, TN · avg 1973 · 832 bridges
- Lancaster County, PA · avg 1973 · 801 bridges
Source: FHWA National Bridge Inventory, 2024 release. Peers floor at 10 bridges so stub inventories cannot own the match.
Fair-condition bridges (60)
I090 W
FairOver: SOUTH ROWLEY ST
0.8 W SD 37 S INTERCH, Davison, SD
Built 1965 Load: 28.7 t ADT: 6,520
I090 E
FairOver: SOUTH ROWLEY ST
0.8 W SD 37 S INTERCH, Davison, SD
Built 1965 Load: 28.7 t ADT: 6,520
I090 W
FairOver: BNSF RR
0.2 E SD 37 S INTERCH, Davison, SD
Built 1967 Load: 28.9 t ADT: 7,065
I090 E
FairOver: BNSF RR
0.2 E SD 37 S INTERCH, Davison, SD
Built 1967 Load: 28.9 t ADT: 7,065
SD037
FairOver: CK
6.5 S I 90 INTERCH, Davison, SD
Built 1946 Load: 32.1 t ADT: 3,929
SD037
FairOver: I090
SD 37 N INTERCHANGE, Davison, SD
Built 1966 Load: 32.4 t ADT: 9,701
403 AVE (FAS 6221)
FairOver: I090
6 E MT VERNON INTERCHANGE, Davison, SD
Built 1965 Load: 34.2 t ADT: 653
SD038
FairOver: JAMES RV
DAVISON-HANSON CO LINE, Davison, SD
Built 1988 Load: 39.0 t ADT: 2,279
SD037 N
FairOver: LAKE MITCHELL SPILLWAY
2.7 N JCT I 90 LOOP, Davison, SD
Built 1960 Load: 54.4 t ADT: 2,460
SD037
FairOver: ENEMY CK
3.6 S I 90 INTERCH, Davison, SD
Built 1946 Load: 66.4 t ADT: 3,929
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.