A hybrid metal-concrete lane separator module intended to be placed on a roadway, the module being a straight element of main axis longitudinally elongated between two connection ends (5, 6) intended to be connected to the connection ends (5, 6) of two other adjacent modules intended to be placed on the roadway, to form an alignment of modules attached to each other and a lane delimiting barrier, each module including toward the bottom a base portion, toward the top a summit portion, connected to each other by uprights (4, 5, 6) extending between the base portion and the summit portion, the module being substantially symmetrical with respect to a longitudinal vertical median plane, the base portion being wider than the summit portion, each connection end (5, 6) having a vertical metallic end face (50, 60) perpendicular to the main axis of the module, the end face (50, 60) being intended to be placed opposite an end face (60, 50) of another module, which is adjacent in the alignment of modules, the connection ends (5, 6) having, on their end faces (50, 60), complementary attachment means (9, 19) for attaching the modules to each other, the complementary attachment means (9, 19) including studs and elongated slots, a given stud fastened on a connection end (5, 6) being intended to be introduced and positioned into a corresponding slot of the other connection end (6, 5), in order to prevent the modules from detaching from each other at least along the main axis, each mushroom-shaped stud including a shaft terminated at its free end by a head that is wider than the shaft, each stud projecting horizontally and parallel to the main axis of the module towards the outside of the end face to which it is fastened, and each slot is vertically elongated and goes through the thickness of the end face (50, 60), at least a portion of each slot having a width permitting the passage of the stud shaft but not of the stud head so that a stud introduced into the corresponding slot can be retained in said slot portion, the stud including a screw provided with an operating head that is wider than the threaded shaft of the screw and the screw being fastened into a nut immobilized at least in rotation at the connection end (5, 6), characterized in that the screw is fastened into the nut, free to be screwed and unscrewed, so as to make adjustable the spacing between the stud head and the end face (50, 60) to which it is fastened, in order to allow adjusting the tightening or the maximum tolerated axial and angular spacing between the connection ends (5, 6) of two connected modules, and in that: * the summit portion is made of metal and includes two longitudinal lateral sides consisted of two continuous, horizontal, parallel lateral slides, separated from each other and held to each other by transverse horizontal spacers, i.e. perpendicular to the slides, the slides longitudinally extending between the two connection ends (5, 6) of the module, and * the base portion includes: - a longitudinal median concrete mass, - two longitudinal lateral sides, each consisted of at least two parallel metallic lateral rails, which are horizontal and vertically superimposed to each other, the lateral rails longitudinally extending between the two connection ends (5, 6) of the module, and - a bottom element closing the base portion downward and transversely extending between the lateral rails of the two lateral sides of the base portion, and longitudinally extending between the two connection ends (5, 6) of the module, said at least two rails on each lateral side of the base portion and the bottom element forming a formwork for the concrete mass, and in that the summit portion, the uprights (4, 5, 6), the slides and the metallic rails are welded to each other. * the summit portion is made of metal and includes two longitudinal lateral sides consisted of two continuous, horizontal, parallel lateral slides, separated from each other and held to each other by transverse horizontal spacers, i.e. perpendicular to the slides, the slides longitudinally extending between the two connection ends (5, 6) of the module, and * the base portion includes: - a longitudinal median concrete mass, - two longitudinal lateral sides, each consisted of at least two parallel metallic lateral rails, which are horizontal and vertically superimposed to each other, the lateral rails longitudinally extending between the two connection ends (5, 6) of the module, and - a bottom element closing the base portion downward and transversely extending between the lateral rails of the two lateral sides of the base portion, and longitudinally extending between the two connection ends (5, 6) of the module, - a longitudinal median concrete mass, - two longitudinal lateral sides, each consisted of at least two parallel metallic lateral rails, which are horizontal and vertically superimposed to each other, the lateral rails longitudinally extending between the two connection ends (5, 6) of the module, and - a bottom element closing the base portion downward and transversely extending between the lateral rails of the two lateral sides of the base portion, and longitudinally extending between the two connection ends (5, 6) of the module,