A light signalling system for automobile and motorcycling competitions, and similar, comprising at least one light graphic panel (2,2a), which can be installed on a respective strut provided at the edge of the track wherein the competition takes place, designed to show encoded images to communicate certain information to the racers on the track, corresponding to the traditional signal flags, at least one control panel to which said light panel (2,2a) is operatively connected, at least one portable control unit operatively connected to said control panel via a Wi-Fi type communication system, said portable control unit including a touch screen type display and displaying on said touch screen type display at least one operating screen, suitable for selecting from time to time encoded images suited to the specific race situation, said portable control unit being further suitable for sending to said control panel at least one signal corresponding to the encoded image to be shown on said panel (2,2a), characterised in that said operating screen comprises at least one enabling button and a plurality of selection buttons, which correspond to all the encoded images that can be displayed on said panel (2,2a), from which a track marshal can select each time, each encoded image being selectable only by applying simultaneous pressure on said enabling button and on the corresponding selection button, said enabling button being held down by the track marshal with one hand, while the other hand presses the selection button corresponding to the encoded image to be displayed, to avoid the selection of an unwanted encoded image by mistake. at least one light graphic panel (2,2a), which can be installed on a respective strut provided at the edge of the track wherein the competition takes place, designed to show encoded images to communicate certain information to the racers on the track, corresponding to the traditional signal flags, at least one control panel to which said light panel (2,2a) is operatively connected, at least one portable control unit operatively connected to said control panel via a Wi-Fi type communication system, said portable control unit including a touch screen type display and displaying on said touch screen type display at least one operating screen, suitable for selecting from time to time encoded images suited to the specific race situation, said portable control unit being further suitable for sending to said control panel at least one signal corresponding to the encoded image to be shown on said panel (2,2a), characterised in that said operating screen comprises at least one enabling button and a plurality of selection buttons, which correspond to all the encoded images that can be displayed on said panel (2,2a), from which a track marshal can select each time, each encoded image being selectable only by applying simultaneous pressure on said enabling button and on the corresponding selection button, said enabling button being held down by the track marshal with one hand, while the other hand presses the selection button corresponding to the encoded image to be displayed, to avoid the selection of an unwanted encoded image by mistake.