Mackinac County Bridge Report Card
Mackinac County scores 46 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Mackinac County, Michigan
Mackinac County has 63 bridges in the National Bridge Inventory, with 10 rated poor and 1 rated scour-critical. Its poor-condition share of 15.9% is above the 11.0% statewide average. Poor-condition bridges carry about 17,739 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Mackinac County a Bridge Condition Exposure Score of 46/100 (F). The county has 63 bridges in the National Bridge Inventory, including 10 in poor condition and 1 rated scour-critical. Poor-condition bridges carry about 17,739 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 | 15.9% | 31.7 |
| Poor-condition traffic exposure | 25 | 19.8% of measured traffic | 14.8 |
| Scour-critical bridge share | 20 | 1.6% | 3.2 |
| Average age vs national baseline | 10 | 58 years vs 48 nationally | 4.1 |
| Traffic-data completeness | 5 | 89,615 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 | 15.9% |
| State Poor-Condition Share | 11.0% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 1.6% |
| Average Bridge Age | 58 years |
| Poor-Condition Traffic Exposure | 17,739 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Mackinac County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| Us-2 over Canadian National Rr | Poor condition + traffic exposure | Poor | 4,114 | 1938 |
| Us-2 over Black River | Poor condition + traffic exposure | Poor | 3,586 | 1939 |
| I-75 over Elmhirst Creek | Poor condition + traffic exposure | Poor | 3,016 | 1963 |
| I-75 NB over Cheeseman RD | Poor condition + traffic exposure | Poor | 2,555 | 1960 |
| I-75 SB over Cheeseman RD | Poor condition + traffic exposure | Poor | 2,555 | 1960 |
| M-123 over I-75 NB | Poor condition + traffic exposure | Poor | 1,808 | 1963 |
| Usfs RTE 3458 over Carp River | Poor condition + traffic exposure | Poor | 50 | 1955 |
| Sherman Road over Shoe-pac River | Poor condition + traffic exposure | Poor | 30 | 1980 |
| Usfs RTE 3445 over Carp River | Poor condition + traffic exposure | Poor | 15 | 1962 |
| Orchard Hill Road over Hog Island Creek | Poor condition + traffic exposure | Poor | 10 | 1997 |
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.