 Sealing of safety zones along the side of the road (also known as a hard-shoulder) can also reduce the risk of head-on collisions caused by steering over-correction.Where a hard shoulder cannot be provided, a "safety edge" can reduce the chances of steering overcorrection.An attachment is added to the paving machine to provide a beveled edge at 30 to 35-degree angle to horizontal, rather than the usual near-vertical edge.