Custer County Bridge Report Card
Custer County scores 62 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Custer County, Idaho
Custer County has 126 bridges in the National Bridge Inventory, with 14 rated poor and 7 rated scour-critical. Its poor-condition share of 11.1% is above the 5.4% statewide average. Poor-condition bridges carry about 2,420 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Custer County a Bridge Condition Exposure Score of 62/100 (D). The county has 126 bridges in the National Bridge Inventory, including 14 in poor condition and 7 rated scour-critical. Poor-condition bridges carry about 2,420 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 | 11.1% | 22.2 |
| Poor-condition traffic exposure | 25 | 6.7% of measured traffic | 5.1 |
| Scour-critical bridge share | 20 | 5.6% | 11.1 |
| Average age vs national baseline | 10 | 47 years vs 48 nationally | 0.0 |
| Traffic-data completeness | 5 | 35,936 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 | 11.1% |
| State Poor-Condition Share | 5.4% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 5.6% |
| Average Bridge Age | 47 years |
| Poor-Condition Traffic Exposure | 2,420 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Custer County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| SH 75 over Yankee Fk Of Salmon Rivr | Poor condition + traffic exposure | Poor | 680 | 1934 |
| East Fork RD over Road Creek | Poor condition + traffic exposure | Poor | 90 | 2022 |
| Squaw Creek Road over Squaw Creek | Poor condition + traffic exposure | Poor | 330 | 1960 |
| Squaw Creek RD over Squaw Creek | Poor condition + traffic exposure | Poor | 330 | 1960 |
| Squaw Creek RD over Squaw Creek | Poor condition + traffic exposure | Poor | 300 | 1960 |
| Beaver-loon Road over Jordan Creek | Poor condition + traffic exposure | Poor | 100 | 1957 |
| Squaw Creek RD over Squaw Creek | Poor condition + traffic exposure | Poor | 100 | 1960 |
| Custer Motorway over Yankee Fork | Poor condition + traffic exposure | Poor | 100 | 1992 |
| Beaver-loon Road over Jordan Creek | Poor condition + traffic exposure | Poor | 100 | 1993 |
| Old Chilli Road over Thousand Springs Creek | Poor condition + traffic exposure | Poor | 80 | 1926 |
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.