Relief Hill Rd over Humbug Creek
Nevada County, California · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Relief Hill Rd over Humbug Creek in Nevada County, California, is rated in poor condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the superstructure, rated 4 (poor condition) on the 0-9 scale.
- It was built in 1952 and reconstructed in 2021, making it 73 years old at the 2025 inventory.
- It carries about 27 vehicles a day (traffic count year 2018).
- Its listed owner is the county highway agency.
- It is one of 19 of the 137 inventoried bridges in Nevada County rated poor (13.9%); 19 (13.9%) are rated poor.
- Its traffic status in the 2025 inventory is posted for load (NBI item 41).
- Its class is unchanged from 2024 (poor), but component ratings moved: superstructure 5 to 4, deck 4 to 5, substructure 7 to 8.
- Its most recent inspection on record is dated August 2024, on a 12-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 → (39.36661, -120.89938)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 4 | 5 | Fair condition |
| Superstructure | 5 | 4 | Poor condition |
| Substructure | 7 | 8 | Very good condition |
Bridge details
| Structure | Continuous steel girder and floorbeam |
| Length | about 22 ft |
| Location | Near Graniteville Rd |
| NBI structure number | 17C0028 |
| Condition class | Poor |
| Traffic status (item 41) | Posted for load |
| Last inspection (item 90) | August 2024 |
| Inspection interval (item 91) | 12 months |
| Scour (item 113) | 5: foundations stable, scour within the limits of the footing or piles |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Nevada County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| State Route 20 over Idaho-maryland Road | 1969 | 47,000 | Fair |
| State Route 20 over Wolf Creek | 1969 | 47,000 | Good |
| State Route 20 over SR 174 (colfax) Auburn | 1970 | 43,000 | Good |
| State Route 20 over Bank Street | 1969 | 34,500 | Good |
| State Route 20 over Bennett Street | 1969 | 34,500 | Fair |
| Interstate 80 over Donner Pass Road | 1991 | 34,000 | Fair |
All bridges nearby: Nevada County, CA bridge conditions · every bridge in Nevada County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.