Road 30n03 over Susan River
Lassen County, California · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Road 30n03 over Susan River in Lassen County, California, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1972 and reconstructed in 1999, making it 53 years old at the 2025 inventory.
- It carries about 20 vehicles a day.
- It is one of 72 of the 108 inventoried bridges in Lassen County rated fair (66.7%); 8 (7.4%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its class is unchanged from 2024 (fair), but component ratings moved: substructure 7 to 6.
- Its most recent inspection on record is dated May 2024, on a 24-month routine inspection cycle.
- 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 → (40.41354, -120.86116)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 6 | 6 | Satisfactory condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 6 | Satisfactory condition |
Bridge details
| Structure | Timber stringer or multi-beam girder |
| Length | about 49 ft |
| Location | 14 Mi W Susanville |
| NBI structure number | 050658000001002 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | May 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 California department of transportation.
Busiest bridges in Lassen County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| State Route 36 over Susan River | 1964 | 15,300 | Fair |
| State Route 36 over Jensen Slough | 1964 | 15,300 | Good |
| State Route 36 over Gold Run Creek | 1964 | 10,300 | Good |
| U.S. Highway 395 over Long Valley Creek | 1956 | 5,500 | Fair |
| U.S. Highway 395 over UP RR & BNSF Ry | 1969 | 5,500 | Fair |
| U.S. Highway 395 over Long Valley Creek Ovfl | 1969 | 5,500 | Fair |
All bridges nearby: Lassen County, CA bridge conditions · every bridge in Lassen County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.