Isabella County Bridge Report Card

Isabella County scores 43 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

F43 / 100

Local infrastructure snapshot

Isabella County, Michigan

Isabella County has 183 bridges in the National Bridge Inventory, with 26 rated poor and 17 rated scour-critical. Its poor-condition share of 14.2% is above the 11.0% statewide average. Poor-condition bridges carry about 44,179 daily vehicle crossings.

183Total Bridges

26Poor (14.2%)

72Fair (39.3%)

17Scour-Critical

Quote-Ready Local Facts

14.2%of county bridges are in poor condition, compared with 11.0% statewide and 6.7% nationally.

44,179daily vehicle crossings are on poor-condition bridges in the county.

17bridges are rated scour-critical, or 9.3% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Isabella County a Bridge Condition Exposure Score of 43/100 (F). The county has 183 bridges in the National Bridge Inventory, including 26 in poor condition and 17 rated scour-critical. Poor-condition bridges carry about 44,179 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	14.2%	28.4
Poor-condition traffic exposure	25	12.9% of measured traffic	9.7
Scour-critical bridge share	20	9.3%	18.6
Average age vs national baseline	10	43 years vs 48 nationally	0.0
Traffic-data completeness	5	342,062 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	14.2%
State Poor-Condition Share	11.0%
National Poor-Condition Share	6.7%
County Scour-Critical Share	9.3%
Average Bridge Age	43 years
Poor-Condition Traffic Exposure	44,179 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeUs-127 NB over Chippewa River — 8,658 vehicles/day Oldest Listed BridgeBaseline Road over Coldwater River — built in 1903 All County BridgesBrowse every bridge record in Isabella County.

Top Bridges to Watch in Isabella County

Bridge	Reason	Condition	Daily Traffic	Year Built
Us-127 NB over Chippewa River	Poor condition + traffic exposure	Poor	8,658	1961
Meridian Road over North Br Chippewa River	Poor condition + traffic exposure	Poor	1,420	1934
Denver Road over North Br Salt River	Poor condition + traffic exposure	Poor	185	1937
Summerton Road over Contrib S Br Salt River	Poor condition + traffic exposure	Poor	185	1937
Denver Road over North Br Chippewa River	Poor condition + traffic exposure	Poor	123	1937
Millbrook Road over Pony Creek	Poor condition + traffic exposure	Poor	56	1939
Us-127 SB over East River RD	Poor condition + traffic exposure	Poor	8,625	1961
Mission Road over Lewis Drain	Poor condition + traffic exposure	Poor	6,140	1930
Mission Road over Spring Creek	Poor condition + traffic exposure	Poor	5,200	1935
Weidman Road over Coldwater River	Poor condition + traffic exposure	Poor	3,604	1966

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.