Terminal tractor

A terminal tractor, known in the United States as a shunt truck, spotter truck, spotting tractor, yard truck, yard shifter, yard dog, yard goat, yard horse, yard bird, yard jockey, 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.
Characteristics.
Distinctions between a terminal tractor and a regular tractor unit include: 
Since off-road versions do not have to drive on roads at highway speeds, a typical top speed is just .