The purpose of the study reported in this paper was to relate the elastomeric nature of a polymer modified asphalt (PAC) to enhanced mix properties. As traditional methods of testing the binder cannot show the specific properties contributed by polymer modification, several new procedures have been developed. To document a correlation between PAC and pavement durability, the results of these tests are examined in conjunction with results of tests on mixes made with these binders. The study included a comparison of the temperature susceptibility and creep response of the binder to the repeated load tests of fatigue, dynamic modulus and rutting resistance. The adhesion of the binder to aggregate was tested with and without moisture exposure. Test results showed that the elasticity, tensile strength, adhesivity and resistance to temperature susceptibility of the PAC binder impart improved stiffness moduli, rutting resistance, fatigue life, adhesion and stripping resistance to the polymer modified bituminous mix.