Abstract: In a break-away coupling for a highway and road side appurtenance, a controlled breaking region is provided which has at least two axial spaced necked-down portions co-axially arranged between the axial ends of the coupling which are configured to be attached both to the appurtenance, at one end, and to the support base, at the other end. Each necked-down portion essentially consists of two axially aligned conical portions inverted one in relation to the other and generally joined at their apices to form a generally hour-glass configuration having a region of minimal cross section at an inflection point having a gradually curved annular concave surface defining a radius of curvature. Each of the two necked-down portion has different radii of curvature that at respective inflection points to provide preferred failure modes as a function of the position and direction of impact of a force on the appurtenance.