Abstract: A portable highway barrier constructed of light weight material has an interior cavity which can be filled with a fluid ballast once it has been transported to a utilization site. The barrier has a box-like configuration defined by vertically-oriented side and end walls, the bottom portion of which is constructed to provide vertically-oriented slots each of which may function to support the lower edge of a vertically-oriented highway sign. The upwardly extending walls of a shallow well formed in the top of the barrier have apertures therein for facilitating attachment to the barrier of highway signs and/or other signalling or control devices such as warning lights. The barrier construction provides for attachment of connecting elements to its end walls so as to enable interconstruction of a plurality of barriers in end to end relationship for traffic channelization.