A bobtail truck is a semi truck that travels from one point to another without a trailer. Sometimes a trucker has to drop off an entire trailer at his destination and travel elsewhere to pick up another trailer. Truckers are often paid round-trip for these bobtail truck jobs.
Since semi trucks are designed to pull trailers, the performance of a bobtail truck suffers on the road, especially in poor road conditions. Semi trucks carry different types of trailers, such as flatbeds, takers, vans and dump trailers. "Bobtail truck" is part of a trucker's lingo; other common terminology includes "gravity checks," "gators," "chicken coop" and "Smokey."