OLD TOPANGA CYN RD
over TOPANGA CYN CRK
50FT W/O TOPANGA CYN RD, Los Angeles County, California
Condition
FairYear Built
1926
Daily Traffic
3,900
Length
8 ft
About This Bridge
OLD TOPANGA CYN RD carries traffic over TOPANGA CYN CRK in Los Angeles County, California. Built in 1926, this structure is 100 years old, making it a historic structure that has served the community for generations. The bridge features wood or timber construction with a truss - thru design, a combination chosen by engineers to meet the specific requirements of this crossing.
Approximately 3,900 vehicles cross this bridge daily, indicating lower traffic volumes common for local roads and rural routes. While traffic is lighter, these bridges still serve essential community transportation needs.
The bridge is currently rated in fair condition based on federal inspection criteria established by the Federal Highway Administration. The structure meets current safety standards for its designated use and load capacity. With a total length of 8 feet, this is a shorter span typical of local road crossings, often carrying traffic over small streams, drainage channels, or other roadways.
The construction materials used in this bridge were selected based on engineering requirements, cost considerations, and local conditions at the time of construction.
Federal law requires that all highway bridges be inspected at least every 24 months by qualified inspectors following the National Bridge Inspection Standards (NBIS). Some bridges with known issues or unusual characteristics may be inspected more frequently. Inspection data is reported to the National Bridge Inventory, a database maintained by the Federal Highway Administration that tracks the condition of all public highway bridges in the United States. This bridge data is sourced from that federal database and reflects the most recent available inspection results.
Condition Ratings
Deck Condition
Good
Superstructure
Fair
Substructure
Good
Channel & Protection
Poor
Lowest Rating
Determines condition category
NBI condition ratings range from 0 (failed) to 9 (excellent). Ratings of 4 or below are considered poor. The overall condition category is determined by the lowest individual component rating.
The fair condition rating of 5 indicates some deterioration that warrants monitoring but doesn't affect structural integrity.
For a structure built in 1926, this condition level is expected given the bridge's age and usage patterns. If this bridge were closed, traffic would face a detour of approximately 10 miles, underscoring the importance of maintaining this crossing.
Bridge Details
Wood or Timber is the primary structural material, which influences maintenance requirements and expected lifespan. The truss - thru design was selected based on span requirements, load capacity needs, and site conditions at the time of construction. Maintenance responsibility falls to County Highway Agency.
Construction
Dimensions
Span dimensions affect structural design choices and load distribution. The deck area of 212 sq ft determines surface maintenance scope.
Classification
Status
Traffic Data
Traffic volume data helps engineers assess bridge wear patterns and plan maintenance schedules. Average Daily Traffic (ADT) counts are updated periodically and represent typical weekday usage.
3,900
Avg Daily Traffic (2012)
Vehicles per day crossing this bridge
—
Truck Traffic
Commercial vehicle percentage
4,300
Projected Future ADT
Estimated future demand
This bridge carries approximately 3,900 vehicles per day, translating to roughly 1,423,500 crossings annually. Lower traffic volumes generally result in less structural wear over time.
Traffic projections estimate future volumes of 4,300 vehicles daily, a 10% increase from current levels. These projections inform capacity planning and potential upgrade requirements.
Load Ratings
Load ratings determine what weight this bridge can safely support. These values are critical for routing heavy vehicles and issuing overweight permits.
Operating Rating
4.2 tons
Maximum allowable load for special permits
Inventory Rating
2.5 tons
Load level for normal traffic
The operating rating of 4.2 tons represents the absolute maximum load this bridge can carry under controlled conditions with special permits. The inventory rating of 2.5 tons is the safe load limit for everyday traffic without restrictions. These relatively low ratings may result in posted weight limits or route restrictions for heavy vehicles.
5-Year Condition Trend
→StableCondition has remained relatively stable since 2020
Data: 2020-2024 FHWA National Bridge Inventory
Location
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34.728056, -119.085556
Identification
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Data Source: Federal Highway Administration (FHWA) National Bridge Inventory 2024
Bridge inspection data is typically updated every 24 months. Conditions may have changed since the last inspection.
“Structurally deficient” does not mean a bridge is unsafe or likely to collapse. It indicates that one or more key structural elements are in poor or worse condition. Bridges are inspected regularly and may have load restrictions in place.
This data is for informational purposes only and should not be used for route clearance or vehicle weight decisions.