What’s Another Name for a Semi Truck?

Semi-trucks, or heavy-duty trucks, are a common sight on the highways of North America. These large trucks are used to transport goods and materials over long distances. They are also known by a variety of other names, including 18-wheelers, big rigs, and semi-trailers.

The term “semi-truck” is derived from the truck’s design, which features a tractor unit and a separate trailer that is connected to the tractor via a fifth wheel coupling. The tractor unit provides power for both the truck itself and the trailer it pulls. The trailer provides extra storage space for cargo that would otherwise be too big or heavy for the tractor unit alone to carry.

Semi-trucks are often referred to as 18-wheelers due to the total number of wheels they have: 10 on the tractor unit, and 8 on the trailer. The term “big rig” is another name for semi-trucks that is used in North America. This term likely originates from their size: they are much larger than traditional pickup trucks and other smaller vehicles on the road.

Finally, semi-trailer is another name used for semi-trucks in some parts of North America. This term likely comes from their design: unlike traditional trucks which have an enclosed body for cargo storage, semi-trucks feature an open frame with an attached trailer that can be detached when not in use.


In conclusion, semi trucks are also known as 18 wheelers, big rigs, or semi trailers depending on where you are located in North America. Regardless of what they’re called though, these large vehicles serve an important purpose in transporting goods across long distances.

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Karen Watkins