Semi’s and Semi-trailers are usually 18-wheeled vehicles that consist of the engine, cab, and trailer. The big rigs usually come with three axles, the front axle to steer, and the two rear axles that are used to propel the vehicle. The added wheel on each side of the truck (double wheels or “dualies”) and on each axle provide support and traction for such a big vehicle. This is the most common type of Semi-truck. Semis and semi-trailers go by many different names such as tractor-trailers, big rigs, semi-trailer trucks, just to name a few. These vehicles transport roughly 70% of all goods in the United States. We provide many different makes and models of this type of vehicle to fit any need you may have.