Luminous system for a lighting and, optionally, signalling device of an automotive vehicle, comprising a first luminous module and a second luminous module; at least the first luminous module being arranged so that the first beam formed by this first luminous module forms only a portion of a statutory low beam-type lighting function, the luminous modules being arranged so that the first beams, when they are activated together, form the totality of a statutory low beam-type lighting function and each luminous module (42; 77) being arranged to form a first beam (11, 21, 60), termed lower beam, participating in the production of a low beam-type lighting function and a second beam (12, 22, 61), termed upper beam, participating in the production of a high beam-type lighting function: the first and second beams formed by each luminous module being selectively activatable; at least one of the luminous modules comprising light-emitting means (34, 32; 70, 71, 76) arranged to form at least two selectively activatable luminous segments (13, 23; 62, 63) in one of the first and second beams formed by this luminous module; each luminous module (42; 77) comprising: - at least first light-emitting sources (30; 70) and second light-emitting sources (34; 71); - at least one optical system (36; 73) formed by a single projection means associated with these first and second light-emitting sources to project the beams from these light-emitting sources outside of the luminous module; said first and second light-emitting sources of each luminous module being arranged to cooperate with the associated optical system respectively to form said first beams (11, 21, 60) and second beams (12, 22, 61) formed by this luminous module, the first and second luminous modules being arranged in one and the same headlight of the automotive vehicle, and characterized in that each of the two luminous modules (42, 77) comprises light-emitting means (34, 32; 71, 76) arranged to form at least two selectively activatable luminous segments (13, 23; 63) in each of the second beams (12, 22; 61) formed by these luminous modules, said at least two selectively activatable luminous segments being disposed so that, between two consecutive segments, there is a gap not lit by said consecutive segments, and in that the light-emitting means (34, 32) of each of the luminous modules are arranged so that the luminous segments formed by the emitting means of the first luminous module are interleaved with the luminous segments formed by the emitting means of the second luminous module when they are activated simultaneously, so that at least one luminous segment formed by the emitting means of the first luminous module, termed first luminous segment, is disposed between two luminous segments formed by the emitting means of the second luminous module, termed second segments. the first and second beams formed by each luminous module being selectively activatable; at least one of the luminous modules comprising light-emitting means (34, 32; 70, 71, 76) arranged to form at least two selectively activatable luminous segments (13, 23; 62, 63) in one of the first and second beams formed by this luminous module; each luminous module (42; 77) comprising: - at least first light-emitting sources (30; 70) and second light-emitting sources (34; 71); - at least one optical system (36; 73) formed by a single projection means associated with these first and second light-emitting sources to project the beams from these light-emitting sources outside of the luminous module; - at least first light-emitting sources (30; 70) and second light-emitting sources (34; 71); - at least one optical system (36; 73) formed by a single projection means associated with these first and second light-emitting sources to project the beams from these light-emitting sources outside of the luminous module; said first and second light-emitting sources of each luminous module being arranged to cooperate with the associated optical system respectively to form said first beams (11, 21, 60) and second beams (12, 22, 61) formed by this luminous module, the first and second luminous modules being arranged in one and the same headlight of the automotive vehicle, and characterized in that each of the two luminous modules (42, 77) comprises light-emitting means (34, 32; 71, 76) arranged to form at least two selectively activatable luminous segments (13, 23; 63) in each of the second beams (12, 22; 61) formed by these luminous modules, said at least two selectively activatable luminous segments being disposed so that, between two consecutive segments, there is a gap not lit by said consecutive segments, and in that the light-emitting means (34, 32) of each of the luminous modules are arranged so that the luminous segments formed by the emitting means of the first luminous module are interleaved with the luminous segments formed by the emitting means of the second luminous module when they are activated simultaneously, so that at least one luminous segment formed by the emitting means of the first luminous module, termed first luminous segment, is disposed between two luminous segments formed by the emitting means of the second luminous module, termed second segments.