Sanilac County Bridge Report Card

Sanilac County scores 41 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

F41 / 100

Local infrastructure snapshot

Sanilac County, Michigan

Sanilac County has 170 bridges in the National Bridge Inventory, with 25 rated poor and 22 rated scour-critical. Its poor-condition share of 14.7% is above the 11.0% statewide average. Poor-condition bridges carry about 21,944 daily vehicle crossings.

170Total Bridges

25Poor (14.7%)

95Fair (55.9%)

22Scour-Critical

Quote-Ready Local Facts

14.7%of county bridges are in poor condition, compared with 11.0% statewide and 6.7% nationally.

21,944daily vehicle crossings are on poor-condition bridges in the county.

22bridges are rated scour-critical, or 12.9% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Sanilac County a Bridge Condition Exposure Score of 41/100 (F). The county has 170 bridges in the National Bridge Inventory, including 25 in poor condition and 22 rated scour-critical. Poor-condition bridges carry about 21,944 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.

Download all county report-card scores as CSV.

How the Score Breaks Down

Factor	Weight	County Value	Penalty
Poor-condition bridge share	40	14.7%	29.4
Poor-condition traffic exposure	25	12.6% of measured traffic	9.4
Scour-critical bridge share	20	12.9%	20.0
Average age vs national baseline	10	47 years vs 48 nationally	0.0
Traffic-data completeness	5	174,206 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	14.7%
State Poor-Condition Share	11.0%
National Poor-Condition Share	6.7%
County Scour-Critical Share	12.9%
Average Bridge Age	47 years
Poor-Condition Traffic Exposure	21,944 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeM-46 over Black River — 5,462 vehicles/day Oldest Listed BridgeLeslie Road over Middle Br Cass River — built in 1905 All County BridgesBrowse every bridge record in Sanilac County.

Top Bridges to Watch in Sanilac County

Bridge	Reason	Condition	Daily Traffic	Year Built
M-46 over Black River	Poor condition + traffic exposure	Poor	5,462	1947
Marlette Road over S Br Cass River I/c Drn	Poor condition + traffic exposure	Poor	2,754	1930
Snover Road over Middle Br Drain	Poor condition + traffic exposure	Poor	742	1930
Freiberger Road over Middle Br Drain	Poor condition + traffic exposure	Poor	200	1970
Huron Line Road over Tyre I/c Drain Ext	Poor condition + traffic exposure	Poor	40	1974
M-53 over Greenman Creek	Poor condition + traffic exposure	Poor	3,600	1927
Galbraith Line RD over Black River	Poor condition + traffic exposure	Poor	1,761	1985
M-19 over S Fork Cass River	Poor condition + traffic exposure	Poor	1,600	1957
Snover Road over S Br Cass River I/c Drn	Poor condition + traffic exposure	Poor	967	1983
Bay City-forestvil over Tyre I/c Drain Extn	Poor condition + traffic exposure	Poor	948	1985

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.