Perkins County Bridge Report Card
Perkins County scores 85 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Perkins County, South Dakota
Perkins County has 60 bridges in the National Bridge Inventory, with 3 rated poor and 1 rated scour-critical. Its poor-condition share of 5.0% is at or below the 16.1% statewide average. Poor-condition bridges carry about 215 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Perkins County a Bridge Condition Exposure Score of 85/100 (B). The county has 60 bridges in the National Bridge Inventory, including 3 in poor condition and 1 rated scour-critical. Poor-condition bridges carry about 215 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.
How the Score Breaks Down
| Factor | Weight | County Value | Penalty |
|---|---|---|---|
| Poor-condition bridge share | 40 | 5.0% | 10.0 |
| Poor-condition traffic exposure | 25 | 2.5% of measured traffic | 1.8 |
| Scour-critical bridge share | 20 | 1.7% | 3.3 |
| Average age vs national baseline | 10 | 36 years vs 48 nationally | 0.0 |
| Traffic-data completeness | 5 | 8,724 measured daily crossings | 0.0 |
Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.
County Comparisons
| County Poor-Condition Share | 5.0% |
| State Poor-Condition Share | 16.1% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 1.7% |
| Average Bridge Age | 36 years |
| Poor-Condition Traffic Exposure | 215 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Perkins County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| White Butte Road over Lodgepole Ck | Poor condition + traffic exposure | Poor | 163 | 1965 |
| Chance Road over Rabbit Ck | Poor condition + traffic exposure | Poor | 26 | 1950 |
| Haynes Road over Lodge Pole Ck | Poor condition + traffic exposure | Poor | 26 | 1980 |
| 183 Avenue over North Fork Grand Rv | Scour-critical foundation rating | Fair | 155 | 1975 |
| Sd073 over Flat Ck | High traffic | Good | 663 | 1995 |
| Sd073 over Grand Rv | High traffic | Fair | 663 | 1995 |
| Sd073 over East Flat Ck | High traffic | Good | 663 | 2018 |
| Sd073 over Moreau Rv | High traffic | Good | 425 | 2016 |
| Sd073 over Flint Rock Ck | High traffic | Good | 425 | 2016 |
| Sd073 over Thunder Butte Ck | High traffic | Good | 423 | 2005 |
Important safety note
Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.