Specifications include, but are not limited to: Rotary mowers shall normally be utilized in the mowing of the right-of-way; however, sickle mowers, side mounts, flail, or boom mowers may be used to mow around bridges, culverts, sign posts, mailboxes, delineators, flex beam guardrails, wet areas, ditches, etc., as approved by the Engineer ; Mowable areas include, but are not limited to, areas under bridges, around guard rails, sign posts, delineators, culvert ends, trees, shrubs, plants, culvert head walls, bridge abutments, bridge or overpass columns and pilings, paved or raised gore areas, paved or raised medians, and along curbs and fences; Mowable vegetation is defined as any tree, vegetation, brush, etc. which is two inches (2”) or less in diameter, measured five inches (5”) above the ground .