Devices and methods for strengthening the upper portions of the support posts for guardrails and guardrail end treatments against the forces that are imparted to the post during an impact. The upper portions of support posts, particularly the areas proximate the bolt connection, are reinforced. Preferably, a compressive force is applied to those areas as well by the reinforcements. In one embodiment, reinforcement for the upper portion of the post is provided by metal banding that is disposed around the periphery of the post. Alternative exemplary embodiments are also described in which reinforcement to the upper portion of the post is provided by plates that are secured into place on a location proximate the connection bolt and by a metal ...