Abstract: Guardrail installation designs are described that incorporate a box beam rail as the structural rail member. The box beam rail member may have an open cross-section or a closed cross-section. An impact head is provided to bend and deflect the rail member during an end-on collision, allowing the rail member to be deflected away from the roadway and out of the path of an end-on impacting vehicle. The impact head includes a striking face and a chute portion that receives the box beam rail member therewithin. In addition to bending and deflecting the rail member, the impact head may also include a flattening section for flattening the rail member.