A module for projecting a light beam comprises: a light source suitable for producing the light beam, a substantially flat support surface on which the source is arranged in a manner such as to emit the light beam from only one side of the surface, and a curved reflecting surface which extends on one side of the support surface and has its concavity facing towards the support surface, and which is capable of reflecting the light beam originating from the source in a principal direction substantially parallel to the support surface of the source, the reflecting surface being divided into a plurality of reflecting areas suitable for receiving respective portions of the light beam. The plurality of reflecting areas comprises at least one area such that the portion of the light beam reflected by that area is substantially collimated in a vertical direction and has a small horizontal divergence α less than a first predetermined angular value α1, and at least one area which is designed in a manner such that the portion of the light beam reflected by that area has a wide horizontal divergence α greater than a second predetermined angular value α2. The area with wide horizontal divergence has a substantially elliptical horizontal cross-section parallel to the flat support surface with one of its foci substantially coinciding with the source and a substantially parabolic vertical cross-section with an axis substantially parallel to the flat support surface and with its focus substantially coinciding with the source.