Merrill Road over Merrill Slough
Tehama County, California · rated Fair in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Merrill Road over Merrill Slough in Tehama County, California, is rated in fair condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the substructure, rated 5 (fair condition) on the 0-9 scale.
- It was built in 1962, making it 63 years old at the 2025 inventory.
- It carries about 90 vehicles a day (traffic count year 2010).
- Its listed owner is the county highway agency.
- It is one of 259 of the 447 inventoried bridges in Tehama County rated fair (57.9%); 21 (4.7%) are rated poor.
- Its traffic status in the 2025 inventory is open, no restriction (NBI item 41).
- Its condition class and component ratings are unchanged from the 2024 inventory.
- Its most recent inspection on record is dated December 2023, 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 → (39.88459, -122.10301)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 5 | 5 | Fair condition |
Bridge details
| Structure | Concrete slab |
| Length | about 25 ft |
| Location | West of Wisconsin Ave |
| NBI structure number | 08C0300 |
| Condition class | Fair |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | December 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 7: scour countermeasures installed |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Tehama County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| Interstate 5 over Biggs Creek | 1940 | 36,500 | Good |
| Interstate 5 over Taylors Wash | 1946 | 36,000 | Fair |
| Interstate 5 over Thomes Creek | 2011 | 29,500 | Fair |
| Interstate 5 over Kopta Creek | 1965 | 29,000 | Fair |
| Interstate 5 over Las Flores Creek | 1965 | 28,000 | Good |
| Interstate 5 over Branch Coyote Creek | 1965 | 28,000 | Good |
All bridges nearby: Tehama County, CA bridge conditions · every bridge in Tehama County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.