Response functions of linear viscoelastic (LVE) materials, dynamic modulus (|E*|) and creep compliance (D(t)) are considered primary mechanical property inputs for flexible pavement in the Mechanistic-Empirical Pavement Design Guide (MEPDG). The contents of this thesis investigate the impact of these mechanical properties on the performance of hot-mix asphalt (HMA) pavement layers in Georgia. Tree-based methods are used to predict |E*| using an existing library of HMA mixtures of differing material properties. Subsequently, an LVE interconversion model is developed to determine D(t) estimates using |E*| in favor of laboratory testing. A performance analysis is provided to determine the most sensitive distress outputs associated with these inputs and to identify the potential necessity for a Level 1 creep compliance library. Ultimately, it is found that such design considerations will significantly impact the international roughness index (IRI), rutting, and thermal cracking performance on long-term flexible pavement sections.