Buffalo County Bridge Report Card
Buffalo County scores 71 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Buffalo County, South Dakota
Buffalo County has 25 bridges in the National Bridge Inventory, with 1 rated poor and 3 rated scour-critical. Its poor-condition share of 4.0% is at or below the 16.1% statewide average. Poor-condition bridges carry about 55 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Buffalo County a Bridge Condition Exposure Score of 71/100 (C). The county has 25 bridges in the National Bridge Inventory, including 1 in poor condition and 3 rated scour-critical. Poor-condition bridges carry about 55 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 | 4.0% | 8.0 |
| Poor-condition traffic exposure | 25 | 0.5% of measured traffic | 0.3 |
| Scour-critical bridge share | 20 | 12.0% | 20.0 |
| Average age vs national baseline | 10 | 50 years vs 48 nationally | 0.7 |
| Traffic-data completeness | 5 | 12,219 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 | 4.0% |
| State Poor-Condition Share | 16.1% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 12.0% |
| Average Bridge Age | 50 years |
| Poor-Condition Traffic Exposure | 55 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Buffalo County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| 355th Avenue over Crow Creek | Poor condition + traffic exposure | Poor | 55 | 1975 |
| Sd045 over Crow Ck | Scour-critical foundation rating | Fair | 949 | 1960 |
| IRR Sd047 over Soldier Ck | Scour-critical foundation rating | Fair | 917 | 1963 |
| Sd045 over Crow Ck | Scour-critical foundation rating | Fair | 755 | 1958 |
| BIA RTE 4 over Campbell Creek | High traffic | Good | 1,720 | 2013 |
| IRR Sd050 over Wolf Ck | High traffic | Fair | 928 | 1954 |
| IRR Sd050 over Crow Ck | High traffic | Good | 928 | 1999 |
| IRR Sd034 over East Fork Soldier Ck | High traffic | Fair | 918 | 1962 |
| Sd045 over Ck | High traffic | Fair | 755 | 1960 |
| State Highway 47 over Big Bend Dam Spillway | High traffic | Fair | 676 | 1963 |
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.