SH 81 over G Canal
Cassia County, Idaho · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- SH 81 over G Canal in Cassia County, Idaho, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 2013, making it 12 years old at the 2025 inventory.
- It carries about 3,400 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 24 of the 117 inventoried bridges in Cassia County rated good (20.5%); 0 (0.0%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated March 2023, on a 48-month routine inspection cycle.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (42.52017, -113.62969)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 7 | Good condition |
Bridge details
| Structure | Concrete frame |
| Length | about 22 ft |
| Location | In Declo |
| NBI structure number | 000000000016621 |
| Condition class | Good |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | March 2023 |
| Inspection interval (item 91) | 48 months |
| Scour (item 113) | 8: foundations stable, scour above the top of the footing |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Idaho department of transportation.
Busiest bridges in Cassia County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| I 84B over Snake River;overland Br | 2001 | 26,000 | Fair |
| I 86 Ebl over I 84 Wbl | 2020 | 19,000 | Good |
| I 84B Sbl over Snake River;heyburn Br. | 1977 | 17,000 | Fair |
| I 84B Nbl over Snake River;heyburn Br. | 1955 | 15,000 | Fair |
| SH 77 over Canal | 1985 | 13,000 | Fair |
| I 84 over Co.rd.;horse Butte Gs | 1963 | 11,500 | Fair |
All bridges nearby: Cassia County, ID bridge conditions · every bridge in Cassia County · Idaho bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.