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Shelby County Bridge Report Card

Shelby County scores 81 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.

B81 / 100
Local infrastructure snapshot

Shelby County, Iowa

Shelby County has 207 bridges in the National Bridge Inventory, with 18 rated poor and 0 rated scour-critical. Its poor-condition share of 8.7% is at or below the 18.6% statewide average. Poor-condition bridges carry about 1,089 daily vehicle crossings.

207Total Bridges
18Poor (8.7%)
111Fair (53.6%)
0Scour-Critical

Quote-Ready Local Facts

8.7%of county bridges are in poor condition, compared with 18.6% statewide and 6.7% nationally.
1,089daily vehicle crossings are on poor-condition bridges in the county.
0bridges are rated scour-critical, or 0.0% of the county bridge inventory.

Copyable Facts for Reporters

BridgeLookup.com gives Shelby County a Bridge Condition Exposure Score of 81/100 (B). The county has 207 bridges in the National Bridge Inventory, including 18 in poor condition and 0 rated scour-critical. Poor-condition bridges carry about 1,089 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

FactorWeightCounty ValuePenalty
Poor-condition bridge share408.7%17.4
Poor-condition traffic exposure251.5% of measured traffic1.1
Scour-critical bridge share200.0%0.0
Average age vs national baseline1046 years vs 48 nationally0.0
Traffic-data completeness571,821 measured daily crossings0.0

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 Share8.7%
State Poor-Condition Share18.6%
National Poor-Condition Share6.7%
County Scour-Critical Share0.0%
Average Bridge Age46 years
Poor-Condition Traffic Exposure1,089 vehicles/day

Bridges to Watch

Busiest Poor-Condition BridgeF24 over Small Stream — 417 vehicles/dayOldest Listed BridgeExchange ST over Drainage — built in 1900All County BridgesBrowse every bridge record in Shelby County.

Top Bridges to Watch in Shelby County

BridgeReasonConditionDaily TrafficYear Built
F24 over Small StreamPoor condition + traffic exposurePoor4171938
FM over Small StreamPoor condition + traffic exposurePoor2401960
FM over Silver CreekPoor condition + traffic exposurePoor1311960
Local over Mosquito CreekPoor condition + traffic exposurePoor351917
Local over Indian CreekPoor condition + traffic exposurePoor351926
Local over Small StreamPoor condition + traffic exposurePoor351959
Local over Small StreamPoor condition + traffic exposurePoor301960
Local over E Branch W. Nish. RiverPoor condition + traffic exposurePoor261920
Local over Mosquito CreekPoor condition + traffic exposurePoor261930
Local over W. NishnabotnaPoor condition + traffic exposurePoor211926

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.