Abstract: The present invention is directed to a vehicle seat assembly comprising a seat assembly frame, a seat and backrest subassembly having a seat pivotally mounted to the frame and a backrest pivotally connected at its lower end to the seat, and a link pivotally connected to the backrest and the frame. The seat and backrest subassembly is movable between a first position to facilitate operation of the vehicle while the driver is sitting and a second position to facilitate operation of the vehicle with the driver standing. When the seat and backrest subassembly is moved from the first position to the second position, the seat moves from a generally horizontal orientation to a generally vertical orientation and the backrest moves upward and forward.