Fs Route No. 312 over Upper W. Branch
Bonner County, Idaho · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Fs Route No. 312 over Upper W. Branch in Bonner County, Idaho, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1954, making it 71 years old at the 2025 inventory.
- It carries about 50 vehicles a day.
- It is one of 11 of the 104 inventoried bridges in Bonner County rated poor (10.6%); 11 (10.6%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated fair in the 2024 inventory and is now poor (substructure 5 to 4).
- Its most recent inspection on record is dated July 2024, on a 24-month routine inspection cycle.
- A poor rating means at least one major component - deck, superstructure, or substructure - is rated 4 or lower on FHWA's 0-9 scale. It does not by itself mean the bridge is unsafe; bridges judged unsafe are closed or load-restricted by their owners.
View this bridge on a map → (48.45702, -116.99272)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 5 | 4 | Poor condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 32 ft |
| Location | Upper West Branch |
| NBI structure number | 010408000000185 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 4: foundations stable, field review says exposed foundations need protection |
Source: FHWA National Bridge Inventory, 2025 data as reported by the Idaho department of transportation.
Busiest bridges in Bonner County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US 95 over Pend Oreille R;sandpoint | 1981 | 18,500 | Fair |
| US 2 over Sand Creek | 1973 | 18,500 | Good |
| US 95 over US 95NB Off R;sand Creek | 2012 | 12,500 | Fair |
| US 95 over Bridge Street | 2012 | 12,500 | Fair |
| US 2 over Pend Oreille R;oldtown B | 1988 | 11,500 | Fair |
| US 95 over Cocolalla Creek | 2017 | 11,500 | Good |
All bridges nearby: Bonner County, ID bridge conditions · every bridge in Bonner County · Idaho bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.