A variety of vehicle-based and warehouse-based solutions are provided to increase the adaptability, utility, and efficiency of materials handling vehicles in the warehouse environment, such as a materials handling vehicle comprising a hand-held drive unit comprising a user interface and an operational command generator responsive to the user interface. 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.