Marshall County Bridge Report Card
Marshall County scores 50 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Marshall County, South Dakota
Marshall County has 38 bridges in the National Bridge Inventory, with 13 rated poor and 0 rated scour-critical. Its poor-condition share of 34.2% is above the 16.1% statewide average. Poor-condition bridges carry about 782 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Marshall County a Bridge Condition Exposure Score of 50/100 (F). The county has 38 bridges in the National Bridge Inventory, including 13 in poor condition and 0 rated scour-critical. Poor-condition bridges carry about 782 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 | 34.2% | 40.0 |
| Poor-condition traffic exposure | 25 | 6.7% of measured traffic | 5.0 |
| Scour-critical bridge share | 20 | 0.0% | 0.0 |
| Average age vs national baseline | 10 | 59 years vs 48 nationally | 4.5 |
| Traffic-data completeness | 5 | 11,645 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 | 34.2% |
| State Poor-Condition Share | 16.1% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 0.0% |
| Average Bridge Age | 59 years |
| Poor-Condition Traffic Exposure | 782 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Marshall County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| 415th Avenue over Crow Creek Ditch | Poor condition + traffic exposure | Poor | 322 | 1974 |
| 100th Street over Wild Rice Creek | Poor condition + traffic exposure | Poor | 80 | 1935 |
| 425th Avenue over Crow Creek | Poor condition + traffic exposure | Poor | 51 | 1940 |
| 418th Avenue over Spain & Langford Ditch | Poor condition + traffic exposure | Poor | 50 | 1979 |
| 422nd Avenue over Spain Ditch | Poor condition + traffic exposure | Poor | 35 | 1930 |
| 416th Avenue over Crow Creek Ditch | Poor condition + traffic exposure | Poor | 35 | 1935 |
| 113th Street over Spain Ditch | Poor condition + traffic exposure | Poor | 35 | 1935 |
| 113th Street over Crow Creek | Poor condition + traffic exposure | Poor | 35 | 1935 |
| 427th Avenue over Wild Rice Creek | Poor condition + traffic exposure | Poor | 35 | 1960 |
| 112th Street over Crow Creek | Poor condition + traffic exposure | Poor | 35 | 1968 |
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.