Why are thy called Semi-Trucks?

Question

Why are thy called Semi-Trucks?

Answer 1

I am a truck mechanic. UCANTCME is exactly right. A semi trailer supports part of it' s weight on its own wheels and part is supported by the tractor. "Semi-Truck" is just slang.

Answer 2

because when going down the road, its 1\2 truck and 1/2 trailer

Answer 3

A "semi tractor" is just a truck designed to pull a semi trailer.

A "semi trailer" is so called because it only has wheels in the rear, not in the front; therefore half the load is supported by the trailer's wheels and the other half is supported by the truck that the trailer is hitched to.