Franklin County Bridge Report Card
Franklin County scores 60 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Franklin County, Idaho
Franklin County has 23 bridges in the National Bridge Inventory, with 2 rated poor and 2 rated scour-critical. Its poor-condition share of 8.7% is above the 5.4% statewide average. Poor-condition bridges carry about 1,310 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Franklin County a Bridge Condition Exposure Score of 60/100 (D). The county has 23 bridges in the National Bridge Inventory, including 2 in poor condition and 2 rated scour-critical. Poor-condition bridges carry about 1,310 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 | 8.7% | 17.4 |
| Poor-condition traffic exposure | 25 | 4.4% of measured traffic | 3.3 |
| Scour-critical bridge share | 20 | 8.7% | 17.4 |
| Average age vs national baseline | 10 | 51 years vs 48 nationally | 1.4 |
| Traffic-data completeness | 5 | 29,500 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 | 8.7% |
| State Poor-Condition Share | 5.4% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 8.7% |
| Average Bridge Age | 51 years |
| Poor-Condition Traffic Exposure | 1,310 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Franklin County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| Weston-fairview RD over Bear River;e.weston Br. | Poor condition + traffic exposure | Poor | 1,000 | 1956 |
| Parkinson Road over Cub River | Poor condition + traffic exposure | Poor | 310 | 1926 |
| SH 34 over Bear River;riverdale Br | Scour-critical foundation rating | Fair | 2,800 | 1960 |
| SH 36 over Bear River | Scour-critical foundation rating | Fair | 1,300 | 1960 |
| US 91 over Cub River | High traffic | Fair | 8,600 | 2006 |
| US 91 over Bear River | High traffic | Fair | 4,200 | 2006 |
| SH 36 over Bear River | High traffic | Good | 3,000 | 2018 |
| US 91 over West Cache Canal | High traffic | Good | 2,300 | 1993 |
| SH 34 over Twin Lakes Canal | High traffic | Fair | 1,200 | 1958 |
| SH 34 over Bear River;cleveland Br. | High traffic | Fair | 1,100 | 1953 |
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.