St. Louis, with its central location and major highway connections, is a key hub for the trucking industry in the Midwest. The trucking world has its own language, and for those new to the business or even locals curious about the terminology they hear on the road or radio, understanding the lingo can be helpful. Whether you’re a new driver, a logistics manager, or someone simply intrigued by the transport world, knowing trucking terms can clear up confusion. One question that often comes up is, “why is it called a semi truck?”—a phrase that itself is tied to common trucking vocabulary and concepts.
Here’s a breakdown of common trucking terms heard around St. Louis and what they mean.
1. Semi Truck
Let’s start with the most frequently asked term—semi truck. A semi truck refers to a combination of a tractor (the engine-powered cab) and a trailer (the cargo container). The term “semi” comes from the trailer itself, which doesn’t have front wheels and needs to be supported by the tractor. It’s semi-independent, meaning it can’t function on its own. That’s the answer to why is it called a semi-truck—it’s all about the trailer’s dependency on the cab.
2. Bobtail
In St. Louis, you might hear someone say they’re driving a “bobtail.” This term refers to a semi truck without a trailer attached. It’s often used when a driver is on their way to pick up a load or returning form a delivery. Driving a bobtail truck handles differently than when it’s loaded, especially in bad weather.
3. Deadhead
Deadheading means driving a truck with an empty trailer. Unlike bobtailing, the trailer is still attached, but there’s no cargo inside. While it may sound inefficient, deadheading is sometimes necessary to reach a pickup location. Fuel usage and wear-and-tear are still factors during deadhead runs.
4. Reefer
“Reefer” is shorthand for refrigerated trailer. These trailers are essential for hauling perishable items like food, pharmaceuticals, and flowers. In a city like St. Louis with major food distribution centers, reefer trucks are a common sight. They require more maintenance due to temperature control systems.
5. Dry Van
A dry van is the most common type of trailer used in general freight hauling. It’s fully enclosed and not temperature-controlled. Dry vans are ideal for items that don’t need special handling and are often used for electronics, clothing, or household goods.
6. Flatbed
A flatbed is an open trailer with no sides or roof. These are ideal for oversized or irregularly shaped loads like machinery, lumber, or steel coils—products frequently moved in and out of industrial zones around St. Louis. Because of their design, loads must be properly secured with straps or chains
7. Logbook / E-Log
Drivers are required to record their hours of service. Traditionally this was done with a physical logbook, but today most drivers use electronic logging devices (E-Logs). These help ensure drivers follow federal regulations regarding rest periods and driving limits.
8.GVWR (Gross Vehicle Weight Rating)
GVWR refers to the maximum operating weight of a truck including the vehicle itself, fuel, cargo, and passengers. Weight limits are particularly important in Missouri, where overloaded trucks can be fined or turned away at weigh stations.
9. LTL and FTL
LTL stands for Less Than Truckload and refers to freight shipments that don’t require a full trailer. FTL is Full Truckload. In LTL shipping, multiple customers share trailer space, which is a cost-effective method commonly used in logistics warehouses across St. Louis.
10. Tandem Axles
Tandem axles are two axles placed closely together at the rear of the truck or trailer. These help distribute weight more evenly and are often adjusted depending on the load. Adjusting the position of tandem axles can also help meet legal weight distribution requirements.
11. Fifth Wheel
Despite the name, the fifth wheel isn’t an actual wheel. It’s the circular coupling device that connects the tractor to the trailer. It allows for pivoting during turns and supports a significant portion of the trailer’s weight.
12. Drop and Hook
This term refers to a shipping strategy where a driver drops off one trailer and hooks up to another. This reduces waiting time and increases efficiency. Many distribution centers around St. Louis use drop and hook to keep operations moving quickly.
Final Thoughts
Understanding these trucking terms isn’t just helpful for drivers—it’s beneficial for anyone working in logistics, supply chain, or even city planning in transportation-heavy regions like St. Louis. From answering basic questions like why is it called a semi truck to grasping the difference between a reefer and a dry van, this knowledge helps demystify the complex world of freight transport.
Next time you hear a trucker on the CB talking about bobtailing or a dispatcher discussing a deadhead run, you’ll know exactly what they mean.
