Alameda County Bridge Report Card
Alameda County scores 80 out of 100 on BridgeLookup's Bridge Condition Exposure Score, based on FHWA National Bridge Inventory records.
Alameda County, California
Alameda County has 662 bridges in the National Bridge Inventory, with 42 rated poor and 6 rated scour-critical. Its poor-condition share of 6.3% is above the 4.9% statewide average. Poor-condition bridges carry about 1,986,214 daily vehicle crossings.
Quote-Ready Local Facts
Copyable Facts for Reporters
BridgeLookup.com gives Alameda County a Bridge Condition Exposure Score of 80/100 (B). The county has 662 bridges in the National Bridge Inventory, including 42 in poor condition and 6 rated scour-critical. Poor-condition bridges carry about 1,986,214 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 | 6.3% | 12.7 |
| Poor-condition traffic exposure | 25 | 5.4% of measured traffic | 4.0 |
| Scour-critical bridge share | 20 | 0.9% | 1.8 |
| Average age vs national baseline | 10 | 52 years vs 48 nationally | 1.7 |
| Traffic-data completeness | 5 | 36,907,472 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 | 6.3% |
| State Poor-Condition Share | 4.9% |
| National Poor-Condition Share | 6.7% |
| County Scour-Critical Share | 0.9% |
| Average Bridge Age | 52 years |
| Poor-Condition Traffic Exposure | 1,986,214 vehicles/day |
Bridges to Watch
Top Bridges to Watch in Alameda County
| Bridge | Reason | Condition | Daily Traffic | Year Built |
|---|---|---|---|---|
| Vallecitos Road over Arroyo Del Valle | Poor condition + traffic exposure | Poor | 19,250 | 1940 |
| Interstate 880 over Crandall Creek | Poor condition + traffic exposure | Poor | 225,000 | 1958 |
| Interstate 880 over Patterson Slough | Poor condition + traffic exposure | Poor | 198,000 | 1957 |
| Interstate 680 over State Route 84 SB & Off | Poor condition + traffic exposure | Poor | 142,000 | 1967 |
| Interstate 680 over Bernal AVE | Poor condition + traffic exposure | Poor | 136,000 | 1967 |
| Interstate 680 over Happy Valley Road | Poor condition + traffic exposure | Poor | 124,000 | 1967 |
| Interstate 680 over Pleasanton-sunol Road | Poor condition + traffic exposure | Poor | 122,000 | 1967 |
| Interstate 580 over Cerrito Creek | Poor condition + traffic exposure | Poor | 99,000 | 1991 |
| Interstate 580 WB over Crow Creek | Poor condition + traffic exposure | Poor | 98,500 | 1988 |
| Interstate 680 NB over State Route 237 (future) | Poor condition + traffic exposure | Poor | 61,000 | 1971 |
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.