Understanding the 7-13 Vehicle Classification System for Traffic Studies
Accurate traffic data collection is the backbone of transportation planning, and vehicle classification plays a central role in this process. The 7 to 13-class vehicle classification system is widely used across countries for analyzing road usage by different vehicle types. This blog explores what these classifications are, why they matter, and how they’re applied in traffic studies.
What Is a Vehicle Classification System?
A vehicle classification system categorizes vehicles based on features such as size, number of axles, weight, and purpose. In traffic engineering, it helps segment traffic flow into manageable data points to support road design, capacity planning, tolling, and policy-making.
7-Class vs. 13-Class Vehicle Classification
The 7-class and 13-class systems are structured classification frameworks commonly used in manual and automated traffic counts. The choice between the two depends on the level of detail required:
7-Class Vehicle Classification:
This basic system is typically used in developing countries or for smaller-scale studies where quick segmentation is sufficient.
Motorcycles
Passenger Cars
Light Commercial Vehicles (LCVs)
Buses
Trucks (2-axle)
Heavy Trucks (3-axle and above)
Others (tractors, auto-rickshaws, etc.)
13-Class Vehicle Classification (FHWA Standard):
This more granular classification is based on the Federal Highway Administration (FHWA) standard, primarily used in the U.S. and by global consultants.
Motorcycles
Passenger Cars
Pickup Trucks
Vans
Buses
2-Axle, 6-Tire Single Unit Trucks
3-Axle Single Unit Trucks
4+ Axle Single Unit Trucks
3-Axle Tractor Trailers
4-Axle Tractor Trailers
5-Axle Tractor Trailers
6+ Axle Tractor Trailers
Special Vehicles (oversized, military, etc.)
Why Use a 13-Class System?
Using a 13-class system allows for:
More accurate road wear estimation
Detailed capacity analysis for freight movement
Precise toll pricing and infrastructure planning
Environmental impact assessments (emissions, fuel types)
Application in Traffic Studies
When traffic data analysts at Traffic Data Count conduct vehicle classification studies, they often recommend the 13-class system for highways, industrial areas, or freight corridors. For city roads or quick surveys, the 7-class may be sufficient.
Common use cases:
Traffic Impact Assessments (TIA)
Feasibility studies for new roadways
Road safety audits
Toll revenue modeling
Emission and noise pollution analysis
Manual vs. Automated Classification
Manual Video Counting: Teams classify vehicles frame-by-frame from video footage, often using tally sheets based on the selected system.
Automated Systems: Use AI and machine learning for live or recorded video classification, offering speed but sometimes lacking accuracy in mixed or low-light conditions.
Conclusion
Whether you’re working with a simple 7-class breakdown or the detailed FHWA 13-class system, proper vehicle classification is essential for meaningful traffic data analysis. It influences everything from road design to transport policy and long-term urban development.
If you need help with accurate vehicle classification for your traffic study, get in touch with our team for expert-led solutions.
