The performance of a flexible pavement under traffic is directly related to the condition of the surface on which the pavement layers are placed. For a full-depth asphalt pavement, if the condition of the subgrade soil is poor, the ultimate durability of the roadway may be reduced. For hot-mix asphalt (HMA) layers placed on top of a new, untreated granular base course, the base material should not be distorted by the trucks carrying the mix to the paver. For HMA placed as an overlay on top of an existing HMA layer, the surface should be free of major distresses, smooth and clean.