A durable, single walled plastic traffic or work area delineator barrel. The single walled barrel is molded in a blow molding operation and handle and base rim flange regions of the barrel in one construction include compressed wall surfaces that define hollow, open-cavity pillars or struts that span between the walls. The pillars are constructed by depressing portions of the walls into contact and thermally bonding the materials together. In another construction corners of the base rim flange include recessed indentations and surface corrugations that are aligned to strengthen the rim flange.