Bridge conditions in San Luis Obispo County, California
402 inventoried bridges · 22 rated poor · 2025 National Bridge Inventory
United States Bridge Conditions2025 National Bridge Inventory, FHWACompiled
San Luis Obispo County tracks close to typical: 22 of its 402 inventoried bridges (5.5%) are rated poor, against a national rate of about 7%.
- 22 of the 402 bridges in San Luis Obispo County, California, are rated in poor condition (5.5%) in the 2025 National Bridge Inventory, as of .
- 210 bridges (52.2%) are rated good and 170 (42.3%) fair.
- The median San Luis Obispo County bridge was built in 1964.
- The busiest poor-rated bridge is Niblick Road over US Highway 101 (built 1987), carrying about 30,055 vehicles a day.
Good 52.2% · Fair 42.3% · Poor 5.5% of 402 bridges
Bridges rated poor
Every bridge in the county with a poor rating, busiest first. Poor means a major component is rated 4 or lower on FHWA's 0-9 scale; it is a repair flag, not a closure notice.
Busiest bridges in the county
| Bridge | Built | Vehicles/day | Condition |
|---|---|---|---|
| U.S. Highway 101 over Stenner Creek | 1978 | 62,000 | Good |
| U.S. Highway 101 over Perfuma Creek | 1948 | 56,000 | Good |
| US Highway 101 NB over Santa Maria River | 1962 | 56,000 | Fair |
| U.S. Highway 101 over Brisco Rd | 1956 | 56,000 | Good |
| U.S. Highway 101 over Whitehorse Draw | 1952 | 54,000 | Good |
| US Highway 101 over St Rte 41 (@PM15.96) | 2010 | 53,000 | Good |
| U.S. Highway 101 over Santa Margarita Creek | 1916 | 43,000 | Good |
| US Highway 101 SB over Paso Robles Creek | 1951 | 31,000 | Fair |
| US Highway 101 NB over Paso Robles Creek | 1939 | 31,000 | Good |
| US Highway 101 SB over Graves Creek | 1951 | 31,000 | Good |
Source: FHWA National Bridge Inventory, 2025. Counts cover inventoried highway bridges over 20 feet; ratings are reported by the state DOT.
Every bridge in San Luis Obispo County → - all 402, busiest first, each with its own condition record.
All of California: California bridge conditions by county · every download on the data page.
Background: how bridge ratings work · what "poor" and "structurally deficient" actually mean · how often bridges are inspected.