Introduction
Have you ever wondered how traffic monitoring systems classify vehicles on the road? In this guide, we will explore the different types of vehicles and their classifications according to the Federal Highway Administration (FHWA). Whether you’re a car enthusiast or simply curious about the inner workings of traffic monitoring, this article will provide you with valuable insights.
Vehicle Types
To accurately classify vehicles, traffic monitoring systems follow specific criteria established by the FHWA. Let’s take a closer look at the various categories:
Motorcycles
Motorcycles encompass all two or three-wheeled motorized vehicles. This category includes motorcycles, motor scooters, mopeds, motor-powered bicycles, and three-wheel motorcycles. With saddle-type seats and handlebar steering, motorcycles offer a thrilling riding experience.
Passenger Cars
Passenger cars, including sedans, coupes, and station wagons, are designed primarily for carrying passengers. This category also includes passenger cars pulling recreational or light trailers. Passenger cars offer comfort, convenience, and a smooth driving experience.
Other Two-Axle, Four-Tire Single Unit Vehicles
This classification encompasses two-axle, four-tire vehicles that are not passenger cars. It includes pickups, panels, vans, and other vehicles such as campers, motor homes, ambulances, hearses, carryalls, and minibuses. Additionally, vehicles within this category pulling recreational or light trailers are included.
Buses
Buses are traditional passenger-carrying vehicles with two axles and six tires or three or more axles. This category includes school buses and other buses designed for carrying passengers. Modified buses, however, are considered trucks and classified accordingly.
Trucks
When reporting information about trucks, certain criteria should be considered:
- Truck tractor units traveling without a trailer are considered single-unit trucks.
- A truck tractor unit pulling other units in a saddle mount configuration is also classified as a single-unit truck, defined by the axles on the pulling unit.
- Vehicles are defined by the number of axles in contact with the road, with floating axles counted only when in the down position.
- The term “trailer” includes both semi- and full trailers.
The classifications for trucks are as follows:
- Two-Axle, Six-Tire, Single-Unit Trucks: These vehicles include trucks, camping and recreational vehicles, motor homes, etc., with two axles and dual rear wheels.
- Three-Axle Single-Unit Trucks: This category includes vehicles with three axles on a single frame, including trucks, camping and recreational vehicles, motor homes, etc.
- Four or More Axle Single-Unit Trucks: These trucks have four or more axles on a single frame.
- Four or Fewer Axle Single-Trailer Trucks: This classification comprises vehicles with four or fewer axles, consisting of a tractor or straight truck power unit and a trailer.
- Five-Axle Single-Trailer Trucks: These vehicles have five axles, consisting of a tractor or straight truck power unit and a trailer.
- Six or More Axle Single-Trailer Trucks: This category includes vehicles with six or more axles, consisting of a tractor or straight truck power unit and a trailer.
- Five or Fewer Axle Multi-Trailer Trucks: These vehicles have five or fewer axles, consisting of three or more units, including a tractor or straight truck power unit.
- Six-Axle Multi-Trailer Trucks: This classification comprises vehicles with six axles, consisting of three or more units, including a tractor or straight truck power unit.
- Seven or More Axle Multi-Trailer Trucks: These vehicles have seven or more axles, consisting of three or more units, including a tractor or straight truck power unit.
Refer to Figure C-1 for a visual representation of the 13 vehicle category classifications used by the FHWA.
Source: Federal Highway Administration
Lift Axles and Classification Consistency
Certain truck configurations utilize axles that can be lifted when the vehicle is empty or lightly loaded. These axles, commonly known as lift axles, drop axles, or tag axles, can affect the classification category of the vehicle. To maintain consistency, the Traffic Monitoring Guide (TMG) recommends considering only the axles in the dropped position when classifying the vehicle. While this promotes consistency, it may present challenges when interpreting classification statistics at specific locations where directional differences exist due to lifted and dropped axles.
FAQs
Q: Are motorcycles considered vehicles?
A: Yes, motorcycles are classified as vehicles. They fall into the category of two or three-wheeled motorized vehicles.
Q: How are trucks classified?
A: Trucks are classified based on their axle configuration and purpose. The FHWA provides various classifications, ranging from two-axle single-unit trucks to multi-trailer trucks with multiple axles.
Q: What is the purpose of classifying vehicles in traffic monitoring systems?
A: Vehicle classification provides valuable data for traffic analysis, infrastructure planning, and decision-making related to road safety and efficiency.
Conclusion
Understanding the classification of vehicles in traffic monitoring systems is essential for accurate data collection and analysis. Whether you’re a car enthusiast, a transportation professional, or simply curious about the inner workings of traffic monitoring, this guide has provided you with comprehensive insights into the various vehicle types and their classifications. Remember, the next time you see a motorcycle or truck on the road, you’ll have a deeper understanding of how they fit into the broader classification system. Stay informed, stay curious, and happy driving!