A materials handling vehicle comprising: a vehicle body comprising a fork side and a power unit side; a plurality of wheels supporting the vehicle body; a traction control unit, a braking system, and a steering assembly, each operatively coupled to one or more of the wheels; a mast assembly and a mast assembly control unit; a fork carriage assembly positioned at the fork side of the vehicle body and being movably coupled to the mast assembly; a picking attachment secured to the fork carriage assembly; an operator compartment movably coupled to the mast assembly and positioned between the fork carriage assembly and the power unit side of the vehicle body; one or more vehicular controllers in communication with the traction control unit, the braking system, the steering assembly, the mast assembly control unit, and the picking attachment; characterized in that the materials handling vehicle further comprises: a drive unit case secured to the vehicle body; and a hand-held drive unit held within the drive unit case and secured to the vehicle body and comprising a user interface and an operational command generator responsive to the user interface, wherein the hand-held drive unit is configured to send operational commands generated in response to user input at the user interface to the vehicular controller(s) to control operational functions of the traction control unit, the braking system, the steering assembly, the mast assembly, the picking attachment, or combinations thereof, and the hand-held drive unit is secured to the vehicle body so as to be accessible for removal from the vehicle body from the power unit side of the vehicle body by an operator sharing a vehicle transit surface with the wheels supporting the vehicle body. a vehicle body comprising a fork side and a power unit side; a plurality of wheels supporting the vehicle body; a traction control unit, a braking system, and a steering assembly, each operatively coupled to one or more of the wheels; a mast assembly and a mast assembly control unit; a fork carriage assembly positioned at the fork side of the vehicle body and being movably coupled to the mast assembly; a picking attachment secured to the fork carriage assembly; an operator compartment movably coupled to the mast assembly and positioned between the fork carriage assembly and the power unit side of the vehicle body; one or more vehicular controllers in communication with the traction control unit, the braking system, the steering assembly, the mast assembly control unit, and the picking attachment; characterized in that the materials handling vehicle further comprises: a drive unit case secured to the vehicle body; and a hand-held drive unit held within the drive unit case and secured to the vehicle body and comprising a user interface and an operational command generator responsive to the user interface, wherein the hand-held drive unit is configured to send operational commands generated in response to user input at the user interface to the vehicular controller(s) to control operational functions of the traction control unit, the braking system, the steering assembly, the mast assembly, the picking attachment, or combinations thereof, and the hand-held drive unit is secured to the vehicle body so as to be accessible for removal from the vehicle body from the power unit side of the vehicle body by an operator sharing a vehicle transit surface with the wheels supporting the vehicle body. a drive unit case secured to the vehicle body; and a hand-held drive unit held within the drive unit case and secured to the vehicle body and comprising a user interface and an operational command generator responsive to the user interface, wherein the hand-held drive unit is configured to send operational commands generated in response to user input at the user interface to the vehicular controller(s) to control operational functions of the traction control unit, the braking system, the steering assembly, the mast assembly, the picking attachment, or combinations thereof, and the hand-held drive unit is secured to the vehicle body so as to be accessible for removal from the vehicle body from the power unit side of the vehicle body by an operator sharing a vehicle transit surface with the wheels supporting the vehicle body. the hand-held drive unit is configured to send operational commands generated in response to user input at the user interface to the vehicular controller(s) to control operational functions of the traction control unit, the braking system, the steering assembly, the mast assembly, the picking attachment, or combinations thereof, and the hand-held drive unit is secured to the vehicle body so as to be accessible for removal from the vehicle body from the power unit side of the vehicle body by an operator sharing a vehicle transit surface with the wheels supporting the vehicle body.