California Bridges
25,848 highway bridges across 58 counties · NBI 2024 data
About California's Bridge Infrastructure
California maintains 25,848 highway bridges across 58 counties, forming critical links in the state's transportation network. With an average construction year of 1970, the typical bridge in California is approximately 56 years old—7 years older than the national average of 49 years. The state's oldest bridge dates back to 1860, representing over a century of service and offering a window into historic bridge engineering practices.
Currently, 5.9% of California's bridges are rated in poor condition, better than the national average of 6.8%. This indicates relatively strong investment in bridge maintenance and replacement programs. A "poor" condition rating indicates significant deterioration requiring attention, though these bridges remain safe for travel at their posted limits. Federal regulations require bridge inspections at least every 24 months to ensure public safety.
Bridge conditions in California reflect decades of infrastructure investment decisions shaped by geography, climate, traffic demands, and available funding. Bridges here carry 26,315 vehicles daily on average—231% higher than the national average—placing greater demands on structural maintenance. The state's 680,064,833 total daily bridge crossings underscore how essential this infrastructure is to daily commerce and commuting.
The material composition of California's bridge inventory reflects regional construction practices and evolving engineering standards. The predominant construction material is concrete, accounting for 61.0% of all structures. Material choice affects maintenance requirements, expected lifespan, and vulnerability to environmental factors specific to the region. Understanding these patterns helps transportation planners allocate resources effectively and prioritize infrastructure investments.
Worst-Rated Bridges
View all 1527 poor-condition bridges →1527 of 25,848 California bridges have a rating of 4 or below. Rating 4 = advanced deterioration.
| # | Bridge | Rating | Location | Built | Daily Traffic |
|---|---|---|---|---|---|
| 1 | OLD COTTONWOOD CR over COTTONWOOD CREEK Critical condition requiring immediate attention. Built 69 years ago, approaching the end of typical service life. Low-traffic rural crossing. | 0 | Siskiyou County Co. · 0.2 MI E/O COTTONWOOD CK | 1957 | 10 |
| 2 | FLOURNOY AVE over BURCH CREEK Critical condition requiring immediate attention. At 89 years old, this is among California's oldest structures. | 0 | Tehama County Co. · 0.2 MI E KIRKWOOD RD | 1937 | 123 |
| 3 | LOW GAP ROAD over MASONITE INDUSTRIAL ROAD Critical condition requiring immediate attention. Built 66 years ago, approaching the end of typical service life. Low-traffic rural crossing. | 0 | Mendocino County Co. · 6.7 MI S ORR SPRINGS ROAD | 1960 | 25 |
| 4 | LAMBERT LANE over ROBINSON CREEK Critical condition requiring immediate attention. Built 72 years ago, approaching the end of typical service life. | 0 | Mendocino County Co. · 0.1 MI W OF SR 128 | 1954 | 379 |
| 5 | STATE PARK ROAD over LITTLE RIVER Critical condition requiring immediate attention. Built 75 years ago, approaching the end of typical service life. | 0 | Mendocino County Co. · VAN DAMME STATE PARK | 1951 | 150 |
| 6 | CONSUMNES MINE RD over NORTH FK COSUMNES RIVER Critical condition requiring immediate attention. Built 68 years ago, approaching the end of typical service life. | 0 | El Dorado County Co. · 4.0 MI N/O GRIZZILY FT RD | 1958 | 950 |
| 7 | WASHINGTON ROAD over EASTSIDE BYPASS Critical condition requiring immediate attention. Built 58 years ago, approaching the end of typical service life. | 0 | Merced County Co. · 0.1 MI E HARMON RD | 1968 | 120 |
| 8 | HOUSTON AVE over CROSS CREEK Critical condition requiring immediate attention. Built 58 years ago, approaching the end of typical service life. | 0 | Kings County Co. · 0.1 MI W OF 6TH AVE | 1968 | 3,190 |
| 9 | AVENUE 404 over COTTONWOOD CREEK Critical condition requiring immediate attention. At 90 years old, this is among California's oldest structures. Low-traffic rural crossing. | 0 | Tulare County Co. · 0.1 MI WEST OF SR 245 | 1936 | 25 |
| 10 | M 112 over DEER CREEK Critical condition requiring immediate attention. Built 70 years ago, approaching the end of typical service life. Low-traffic rural crossing. | 0 | Tulare County Co. · 2.23 MI SE OF M120 | 1956 | 25 |
Bridges by County
Los Angeles County holds 14% of California's bridges. Contra Costa County has the highest deficiency rate.
| County | Bridges ↓ | Condition | Poor | Poor % | Avg ADT |
|---|---|---|---|---|---|
| Los Angeles County Largest bridge inventory in California. High-traffic area averaging 66,160 vehicles per bridge daily. | 3,547 | 1,617 1,717 | 120 | 3.4% | 66,160 |
| San Diego County One of California's largest bridge inventories. High-traffic area averaging 34,376 vehicles per bridge daily. | 1,632 | 744 790 | 50 | 3.1% | 34,376 |
| San Bernardino County One of California's largest bridge inventories. High-traffic area averaging 27,809 vehicles per bridge daily. | 1,422 | 648 688 85 | 85 | 6.0% | 27,809 |
| Orange County High-traffic area averaging 54,658 vehicles per bridge daily. | 1,164 | 531 563 | 35 | 3.0% | 54,658 |
| Riverside County Below-average deficiency rate. High-traffic area averaging 34,360 vehicles per bridge daily. | 1,117 | 509 541 | 27 | 2.4% | 34,360 |
| Santa Clara County High-traffic area averaging 32,499 vehicles per bridge daily. | 964 | 440 467 54 | 54 | 5.6% | 32,499 |
| Fresno County | 916 | 418 443 | 35 | 3.8% | 10,939 |
| Sacramento County High-traffic area averaging 27,726 vehicles per bridge daily. | 740 | 337 358 | 25 | 3.4% | 27,726 |
| Kern County | 668 | 305 323 44 | 44 | 6.6% | 13,260 |
| Alameda County Poor condition rate significantly above state average. High-traffic area averaging 56,133 vehicles per bridge daily. | 658 | 300 318 63 | 63 | 9.6% | 56,133 |
Infrastructure Profile
| Average bridge age | 56 years |
| Average year built | 1970 |
| Oldest bridge | 1860 |
| Newest bridge | 2023 |
| Avg daily traffic/bridge | 26,315 |
| Total daily crossings | 680.1M |
California vs. National Average
Inspections typically occur every 24 months. Structurally deficient does not mean unsafe.