A driving assistance device including means for determining a target speed, means for comparing an instantaneous speed of the railway vehicle with the target speed or with an interval around the target speed, and means for displaying driving instructions intended for a conductor of the railway vehicle, the driving instructions including instructions for modifying the instantaneous speed in order to bring it closer to the target speed, the display means being configured to: display a speed increase instruction icon when the instantaneous speed is below a first predetermined value, and to display a speed decrease instruction icon when the instantaneous speed is above a second predefined value.