Logan County Bridge Report Card
Logan County scores 79 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Logan County, Illinois
Logan County has 292 bridges in the National Bridge Inventory, with 27 rated poor and 0 rated scour-critical. Its poor-condition share of 9.2% is at or below the 9.5% statewide average. Poor-condition bridges carry about 9,405 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Logan County a Bridge Condition Exposure Score of 79/100 (C). The county has 292 bridges in the National Bridge Inventory, including 27 in poor condition and 0 rated scour-critical. Poor-condition bridges carry about 9,405 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 | 9.2% | 18.5 |
| Poor-condition traffic exposure | 25 | 1.5% of measured traffic | 1.2 |
| Scour-critical bridge share | 20 | 0.0% | 0.0 |
| Average age vs national baseline | 10 | 50 years vs 48 nationally | 1.0 |
| Traffic-data completeness | 5 | 606,935 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 | 9.2% |
| State Poor-Condition Share | 9.5% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 0.0% |
| Average Bridge Age | 50 years |
| Poor-Condition Traffic Exposure | 9,405 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Logan County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| I-155 & Ramps A & over S Fk Prairie Creek | Poor condition + traffic exposure | Poor | 5,825 | 1990 |
| South Beason RD over Deer Ck Br | Poor condition + traffic exposure | Poor | 800 | 1965 |
| Palmer AVE over Brainards Branch | Poor condition + traffic exposure | Poor | 500 | 1966 |
| Bl 55 (old US 66) over I-55 | Poor condition + traffic exposure | Poor | 500 | 1973 |
| Waynesville Road over Kickapoo Creek | Poor condition + traffic exposure | Poor | 325 | 1980 |
| Tr 199a over Lake Fork | Poor condition + traffic exposure | Poor | 225 | 1978 |
| New Holland-san Jo over Prairie Ck | Poor condition + traffic exposure | Poor | 150 | 1961 |
| Tr-56 over Lake Fork Creek Trib | Poor condition + traffic exposure | Poor | 100 | 1958 |
| Tr 176 over Lake Fork Ck Fld Pln | Poor condition + traffic exposure | Poor | 100 | 1965 |
| Tr 9 over Prairie Ck | Poor condition + traffic exposure | Poor | 75 | 1964 |
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.