San Luis Obispo County Bridge Report Card
San Luis Obispo County scores 77 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
San Luis Obispo County, California
San Luis Obispo County has 402 bridges in the National Bridge Inventory, with 22 rated poor and 10 rated scour-critical. Its poor-condition share of 5.5% is above the 4.9% statewide average. Poor-condition bridges carry about 201,471 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives San Luis Obispo County a Bridge Condition Exposure Score of 77/100 (C). The county has 402 bridges in the National Bridge Inventory, including 22 in poor condition and 10 rated scour-critical. Poor-condition bridges carry about 201,471 daily vehicle crossings. Poor condition does not mean unsafe; bridges judged unsafe are closed or restricted by transportation agencies.
How the Score Breaks Down
| Factor | Weight | County Value | Penalty |
|---|---|---|---|
| Poor-condition bridge share | 40 | 5.5% | 10.9 |
| Poor-condition traffic exposure | 25 | 5.6% of measured traffic | 4.2 |
| Scour-critical bridge share | 20 | 2.5% | 5.0 |
| Average age vs national baseline | 10 | 55 years vs 48 nationally | 2.9 |
| Traffic-data completeness | 5 | 3,578,107 measured daily crossings | 0.0 |
Score = 100 minus weighted penalties. The score is a comparative research signal, not an official safety rating. Read the full methodology.
County Comparisons
| County Poor-Condition Share | 5.5% |
| State Poor-Condition Share | 4.9% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 2.5% |
| Average Bridge Age | 55 years |
| Poor-Condition Traffic Exposure | 201,471 vehicles/day |
Bridges to Watch
Top Bridges to Watch in San Luis Obispo County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| State Route 1 over Santa Maria River | Poor condition + traffic exposure | Poor | 5,000 | 1955 |
| Huasna RD over Arroyo Grande Creek | Poor condition + traffic exposure | Poor | 966 | 1923 |
| Asuncion Road over Trout Creek | Poor condition + traffic exposure | Poor | 371 | 1969 |
| Huasna Townsite RD over Huasna River | Poor condition + traffic exposure | Poor | 288 | 1965 |
| Niblick Road over US Highway 101 | Poor condition + traffic exposure | Poor | 30,055 | 1987 |
| US Highway 101 SB over Atascadero Creek | Poor condition + traffic exposure | Poor | 30,000 | 1956 |
| US Highway 101 NB over Atascadero Creek | Poor condition + traffic exposure | Poor | 30,000 | 1956 |
| US Highway 101 SB over Traffic Way | Poor condition + traffic exposure | Poor | 30,000 | 1956 |
| US Highway 101 NB over Traffic Way | Poor condition + traffic exposure | Poor | 30,000 | 1956 |
| US Highway 101 SB over Santa Margarita Creek | Poor condition + traffic exposure | Poor | 21,000 | 1956 |
Important safety note
Poor condition does not mean a bridge is unsafe. It means at least one major component has significant deterioration and the bridge is a priority for maintenance, repair, or replacement. Bridges judged unsafe are closed or restricted by transportation agencies.