Abstract: An improved concrete block intended to serve as a roadway defining member. The block is in the shape of an elongate concrete body having an essentially triangular cross-sectional configuration with one bottom face and two preferably symmetrical side faces. Each side face is formed closest to the bottom face with a straight threshold portion sloping at a gradient of 1:5, which portion is connected to a second straight portion sloping at a gradient of 1:7 via an essentially circularly arcuate concave portion.

Abstract: An arrangement in concrete blocks which are intended to be positioned end-to-end to form barriers for e.g. roadways and parking lots. The concrete blocks have an elongate shape with an essentially triangular cross-sectional configuration with rounded side walls, and are interconnected by means of T-shaped metal pieces, the latter being secured in the end faces of the blocks during the casting thereof and formed with cross-bars, the interconnection of the blocks being effected in that two such cross-bars at adjoining end faces of two concrete blocks positioned end-to-end are enclosed by a tubular member, whereby the blocks are locked together. The blocks may be provided with a device widening their upper part and increasing the ability of the block to guide vehicles safely back to the roadway.