Sonora Road over Martells Creek
Stanislaus County, California · rated Poor in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Sonora Road over Martells Creek in Stanislaus County, California, 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 1920, making it 105 years old at the 2025 inventory.
- It carries about 182 vehicles a day (traffic count year 2016).
- Its listed owner is the county highway agency.
- It is one of 52 of the 386 inventoried bridges in Stanislaus County rated poor (13.5%); 52 (13.5%) 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 September 2023, on a 24-month routine inspection cycle.
- It is coded scour critical (NBI item 113 = 3): scour critical: foundations unstable for the assessed or calculated scour.
- 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 → (37.86251, -120.77441)
Component ratings
| Component | Rating (2024) | Rating (2025) | FHWA scale meaning |
|---|---|---|---|
| Deck | 7 | 7 | Good condition |
| Superstructure | 7 | 7 | Good condition |
| Substructure | 4 | 4 | Poor condition |
Bridge details
| Structure | Continuous concrete tee beam |
| Length | about 81 ft |
| Location | 0.1MI E Frankenheimer Rd |
| NBI structure number | 38C0272 |
| Condition class | Poor |
| Traffic status (item 41) | Open, no restriction |
| Last inspection (item 90) | September 2023 |
| Inspection interval (item 91) | 24 months |
| Scour (item 113) | 3: scour critical: foundations unstable for the assessed or calculated scour |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Stanislaus County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| State Route 99 over 9TH Street & UP RR | 1963 | 121,000 | Fair |
| State Route 99 over Second St-sb 99 on Ramp | 1965 | 101,000 | Good |
| State Route 99 over SB 99-north St Off Ramp | 1965 | 101,000 | Good |
| State Route 99 over Ceres Main Canal | 1941 | 96,000 | Fair |
| State Route 99 over Mitchell Rd | 1965 | 96,000 | Fair |
| Briggsmore Road over UP RR & Brink Avenue | 1976 | 71,797 | Poor |
All bridges nearby: Stanislaus County, CA bridge conditions · every bridge in Stanislaus County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.