<p>The invention relates to a support structure for use in supporting a road sign or the like. A longitudinal tubular support member has a uniform cross-section that includes a plurality of circular or part-circular port sections for receiving an end anchorage. Enclosing wall sections extend between the port sections and are shaped to include a concave form so as to promote inward collapsing of the support member in the event of an impact to the support structure.</p>