A drive system for a work vehicle comprises a control unit adapted to: monitor output of a speed ratio setting input device for a speed ratio setting request signal and output of a drive-request input device for a FWD-only request signal, determine from the speed ratio setting request signal if a requested speed ratio setting represented thereby is one of at least one predetermined speed ratio setting among a plurality of speed ratio settings possible for the work vehicle upon receipt of the FWD-only request signal, and, if so, output at least one control signal engaging a FWD-only mode enabling FWD operation of the work vehicle but disabling RWD operation of the work vehicle. An associated method is disclosed.