Abstract: An apparatus wherein a plurality of spaced tubular supports are secured together by a flexible tether line, wherein respective outer distal tubular support members include a respective outer tether line that in turn is secured to a respective spike member for projection into ground surface on opposed sides of a highway structure. Plural pairs of spaced parallel spikes defining an acute angle therebetween, wherein intermediately spaced pairs of piercing spikes is a third spike bisecting an obtuse included angle defined by the first and second spike members of each spike pair, wherein the first, second, and third spike members define an acute angle of approximately 120 degrees therebetween.