A reliability-based mix design and analysis system has been developedfor mitigating fatigue distress in asphalt pavements. Design decisionsconsider not only fundamental mix properties but also the levelof design traffic, the temperature environment at the site, thepavement structural section, laboratory testing and constructionvariabilities, and the acceptable level of risk. This paper describesthe mix design and analysis system, discusses its calibration,illustrates its use, and assesses the consistency of current Californiadesign practice vis- a-vis the control of fatigue distress. Itreveals possible inconsistencies in current California designpractice, discusses effects of construction variability, highlightsadvantages of rich-bottom pavement structures, and illustratesthe integration of mix and structural components into a reliability-basedmix design process.