Abstract: A single lever control unit for operating a vehicle that is driven by first and second variable displacement, reversible hydraulic motors is disclosed herein. The single handle control lever is capable of simultaneously moving a pair of control arms the same amount in either direction to control the forward and reverse speed of movement of the vehicle and also to vary the amount of movement of the control arms by moving the lever about a second pivot axis to control the direction of movement of the vehicle. The control unit also incorporates a releasable lock member that is capable of holding the control arms in an adjusted position so that the vehicle may be driven at a given forward or reverse speed without any forces being applied to the control lever.