Westside Rd over Porter Creek
Sonoma County, California · rated Good in the 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
- Westside Rd over Porter Creek in Sonoma County, California, is rated in good condition in the 2025 National Bridge Inventory (as of ).
- Its lowest-rated component is the deck, rated 7 (good condition) on the 0-9 scale.
- It was built in 1921, making it 104 years old at the 2025 inventory.
- It carries about 1,738 vehicles a day (traffic count year 2016).
- Its listed owner is the county highway agency.
- It is one of 138 of the 611 inventoried bridges in Sonoma County rated good (22.6%); 32 (5.2%) are rated poor.
- A good rating means every major component - deck, superstructure, substructure, or culvert - is rated 7 or higher on FHWA's 0-9 scale: no more than minor problems.
View this bridge on a map → (38.51788, -122.89019)
Component ratings
| Component | Rating (2025) | FHWA scale meaning |
|---|---|---|
| Deck | 7 | Good condition |
| Superstructure | 7 | Good condition |
| Substructure | 7 | Good condition |
Bridge details
| Structure | Concrete tee beam |
| Length | about 32 ft |
| Location | 1.0 Mi N Wohler Br |
| NBI structure number | 20C0138 |
| Condition class | Good |
Source: FHWA National Bridge Inventory, 2025 data as reported by the California department of transportation.
Busiest bridges in Sonoma County
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| US Highway 101 over College Avenue | 2009 | 136,500 | Fair |
| U.S. Route 101 over Future Rainier Avenue | 2022 | 103,000 | Fair |
| US Highway 101 over 3RD St 4TH St & 5TH St | 1968 | 96,000 | Fair |
| US Highway 101 over Ninth Street | 1968 | 96,000 | Fair |
| U.S. Highway 101 over Santa Rosa Creek | 2009 | 96,000 | Fair |
| U.S. Highway 101 over Sixth Street | 2009 | 96,000 | Fair |
All bridges nearby: Sonoma County, CA bridge conditions · every bridge in Sonoma County · California bridges.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.