Propulsion system for self-propelled construction machine

The drive system has an internal combustion engine (38) that can be operated to engage elements via a gearbox (66) with at least two freely selectable gear stages for driving the machine, whereby a controller (40) is connected to a gear selection actuator (112,118) and can be operated to automatically select a gear ratio. The controller can be operated to detect the operating mode of the working machine using a mode selector (126) operated by an operator.