Lassen Lane over Interstate 5
Siskiyou County, California · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Lassen Lane over Interstate 5 in Siskiyou County, California, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 6 (satisfactory condition) on the 0-9 scale.
- It was built in 1964, making it 61 years old at the 2025 inventory.
- It carries about 2,650 vehicles a day (traffic count year 2024).
- Its listed owner is the state highway agency.
- It is one of 230 of the 425 inventoried bridges in Siskiyou County rated fair (54.1%); 25 (5.9%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- It was rated good in the 2024 inventory and is now fair (substructure 7 to 6).
- Its most recent inspection on record is dated July 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 → (41.31926, -122.32555)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 7 | 6 | Satisfactory condition |
Bridge details
| Structure | Continuous concrete tee beam |
| Length | about 206 ft |
| Location | 02-sis-005-r11.17-msha |
| NBI structure number | 02 0067 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | July 2024 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | N: not over a waterway |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Siskiyou County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Interstate 5 SB over UP RR & Amtrak | 1964 | 20,000 | Fair |
| Interstate 5 NB over UP RR & Amtrak | 1964 | 20,000 | Fair |
| Interstate 5 over Mott Road | 1976 | 20,000 | Good |
| Interstate 5 over Mott Road | 1976 | 20,000 | Fair |
| Interstate 5 over Dunsmuir Ave | 1976 | 19,200 | Good |
| Interstate 5 over Sacramento UP RR Amtrak | 1955 | 18,000 | Good |
All bridges nearby: Siskiyou County, CA bridge conditions · every bridge in Siskiyou County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.