Load associated fatigue cracking is one of the major distress types occurring in flexible pavement systems.Flexural bending beam fatigue laboratory test has been used for several decades and is considered to be anintegral part of the new superpave advanced characterization procedure. One of the most significant solutionsto prolong the fatigue life for an asphaltic mixture is to utilize flexible materials as rubber or polymer fibers.A laboratory testing program was performed at Arizona State University (ASU) on a reference, AsphaltRubber (AR) and polymer modified gap graded mixtures. Strain controlled fatigue tests were conductedaccording to American Association of State Highway and Transportation Officials (AASHTO) procedures.Using COANOVA statistical analysis approach, the results from the beam fatigue tests indicated that the ARand polymer modified gap graded mixtures would have much longer fatigue life compared with the reference(conventional) mixtures.