Humboldt County Bridge Report Card
Humboldt County scores 80 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Humboldt County, Iowa
Humboldt County has 87 bridges in the National Bridge Inventory, with 7 rated poor and 0 rated scour-critical. Its poor-condition share of 8.0% is at or below the 18.6% statewide average. Poor-condition bridges carry about 192 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Humboldt County a Bridge Condition Exposure Score of 80/100 (B). The county has 87 bridges in the National Bridge Inventory, including 7 in poor condition and 0 rated scour-critical. Poor-condition bridges carry about 192 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 | 8.0% | 16.1 |
| Poor-condition traffic exposure | 25 | 0.3% of measured traffic | 0.2 |
| Scour-critical bridge share | 20 | 0.0% | 0.0 |
| Average age vs national baseline | 10 | 57 years vs 48 nationally | 3.9 |
| Traffic-data completeness | 5 | 60,979 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 | 8.0% |
| State Poor-Condition Share | 18.6% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 0.0% |
| Average Bridge Age | 57 years |
| Poor-Condition Traffic Exposure | 192 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Humboldt County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| Local over Dm River | Poor condition + traffic exposure | Poor | 60 | 1911 |
| 215th ST over Des Moines River | Poor condition + traffic exposure | Poor | 50 | 1899 |
| FM over Dm River | Poor condition + traffic exposure | Poor | 30 | 1905 |
| Local over Prairie Creek | Poor condition + traffic exposure | Poor | 15 | 1900 |
| Local over Drainage Ditch | Poor condition + traffic exposure | Poor | 15 | 1948 |
| Local over Dd | Poor condition + traffic exposure | Poor | 11 | 1900 |
| Local over Dm River | Poor condition + traffic exposure | Poor | 11 | 1924 |
| US 169 over W Fork Des Moines River | High traffic | Fair | 7,100 | 1997 |
| US 169 over Indian Creek | High traffic | Good | 5,400 | 2011 |
| Ia 3 over Stream | High traffic | Good | 4,590 | 1939 |
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.