Terminal tractor

A terminal tractor, known in the United States as a shag truck, shunt truck, spotter truck, spotting tractor, yard truck, yard shifter, yard dog, yard goat, yard horse, yard mule, yard jockey, yard spotter, hostler, or mule, is a kind of semi-tractor intended to move semi-trailers within a cargo yard, warehouse facility, or intermodal facility, much like a switcher locomotive is used to position railcars. In the United Kingdom they are known as terminal lorries or terminal trucks.In the United States the term is most often called a yard driver or switcher, often given the nickname yard dog, affectionately not derogatively. Yard dogs are generally thought well of by other drivers because they will often back trailers into docks that are narrow or difficult to pull off by large OTR tractors with sleeper berths.

Some manufacturers include Terberg from The Netherlands and Kalmar Ottawa from the U.S.