Abstract: A post construction is disclosed wherein an upper post section has its lower portion disposed in overlapped relation with the upper end portion of a lower post section and is connected thereto through a pair of breakaway elements which facilitate breakaway movement of the upper post section relative to the lower post section when the upper section is subjected to a predetermined impact force such as from a motor vehicle. A retainer bar is connected to the upper and lower post sections in a manner to prevent complete release of the post sections from each other upon impact, the retainer bar having lost motion connection with at least one of the post sections in a manner to substantially dissipate the impact force. In a preferred embodiment, the retainer bar is formed with offset web contact portions adapted to engage the opposed webs of the superimposed post sections and establish solid interconnection therebetween.