Abstract: A visual display unit for displaying variations in the quotient of applied load and safe working load for a vehicle, such as a mechanical handling or load-carrying vehicle, has a pictorial representation of the vehicle applied to a display panel and a plurality of lights positioned around the representation and arranged to be illuminated at different predetermined quotient levels so as to provide a primary visual indication of an increase in load towards an unsafe condition. In addition the lights and the representation are mutually disposed such that a secondary visual indication is provided showing the cause of an increase in applied load and how it may be reduced.