I 15 Nbl over SH 40;DOWNEY Ic
Bannock County, Idaho · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- I 15 Nbl over SH 40;DOWNEY Ic in Bannock County, Idaho, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1971 and reconstructed in 1987, making it 54 years old at the 2025 inventory.
- It carries about 6,000 vehicles a day (traffic count year 2023).
- Its listed owner is the state highway agency.
- It is one of 74 of the 128 inventoried bridges in Bannock County rated fair (57.8%); 6 (4.7%) are rated poor.
- A fair rating means the lowest-rated major component scores 5 or 6 on FHWA's 0-9 scale: some deterioration or minor section loss, but the structure is sound. It is the middle class, not a warning.
View this bridge on a map → (42.43044, -112.18219)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 5 | Fair condition |
| Superstructure | 5 | Fair condition |
| Substructure | 6 | Satisfactory condition |
Bridge details
| Structure | Prestressed concrete stringer or multi-beam girder |
| Length | about 162 ft |
| Location | 10.3 S. Arimo |
| NBI structure number | 000000000011075 |
| Condition class | Fair |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Idaho department of transportation.
Busiest bridges in Bannock County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 91 ;quinn Rd. over Uprr;quinn Road Op | 1986 | 22,500 | Good |
| I 15 Sbl over I 86 WB Ramp | 2024 | 19,250 | Good |
| I 15 Nbl over I 86 WB Ramp | 2023 | 19,250 | Good |
| I 15 Sbl over I 86 EB Ramp | 2024 | 19,250 | Good |
| I 15 Sbl over STP7041;CHUBBUCK Road | 2024 | 19,250 | Good |
| I 15 Nbl over I 15B;POCATELLO Creek Ic | 1999 | 19,000 | Fair |
All bridges nearby: Bannock County, ID bridge conditions · every bridge in Bannock County · Idaho bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.