Tractor-truck cab with workstation and mobile seat

This invention relates to cab units for use with tractor-trailer rigs and the like. Provided herein is a cab for a tractor-truck. The cab includes a work station, suitable for use as a desk or the like, which can be provided with common office machines. Also provided in the cab is a seat, which is slidably fixed to a seat-supporting track that extends across the floor of the cab, so that the seat can be selectively positioned between a driving position and a workstation position. The tractor-truck can be equipped with an interlock system that keeps the vehicle from moving if the seat is not in the driving position. Also, when the seat is not in the workstation position, a second seat can be detachably fixed in the workstation position.