Bridge conditions in Canyon County, Idaho
291 inventoried bridges · 6 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
6 of the 291 bridges the federal inventory lists in Canyon County are rated poor; the rest split 86 good and 199 fair.
- 6 of the 291 bridges in Canyon County, Idaho, are rated in poor condition (2.1%) in the 2025 National Bridge Inventory, as of .
- 86 bridges (29.6%) are rated good and 199 (68.4%) fair.
- The median Canyon County bridge was built in 1984.
- The busiest poor-rated bridge is Nhs 7773;10TH Ave over City St;uprr;caldwell Op (built 1956), carrying about 19,500 vehicles a day.
Good 29.6% · Fair 68.4% · Poor 2.1% of 291 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Nhs 7773;10TH Ave over City St;uprr;caldwell Op | 1956 | 19,500 | Poor |
| Blaine St over Old Indian Creek Channel | 1966 | 5,400 | Poor |
| Stc 7787;PLYMOUTH over Boise River & Canal | 1922 | 2,100 | Poor |
| Sma 7733;KIMBALL A over Indian Creek | 1933 | 2,000 | Poor |
| Stc 8317;DUFF Lane over Willow Creek | 1983 | 750 | Poor |
| Stc 3851;HEXON Rd over Boise River | 1954 | 560 | Poor |
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 84 Wbl & Ebl over I 84B ;garrity Blvd Ic | 2011 | 111,000 | Good |
| I 84 Ebl & Wbl over Uprr;east Lateral Canal | 2021 | 104,000 | Good |
| I 84 Ebl Wbl over Northside Blvd Ic | 2021 | 84,500 | Good |
| I 84 Ebl Wbl over Sma 7923; Linden Road Gs | 2022 | 68,000 | Good |
| I84 Ebl Wbl over Notus Canal | 2022 | 68,000 | Good |
| I 84 ;US 20-26 over Stp 7773;10TH Ave Ic | 1983 | 58,000 | Fair |
| I 84 Ebl over Phyllis Canal | 2012 | 55,500 | Good |
| I 84 Wbl over Phyllis Canal | 2012 | 55,500 | Good |
| I 84 Ebl over UPRR | 2011 | 55,500 | Good |
| I 84 Wbl over UPRR | 2011 | 55,500 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
All of Idaho: Idaho bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.