The reuse of waste crumb rubber (CR) (used tyres) and Polyethylene Terephthalate (PET) (plastic beverage bottles) is of particular interest in Trinidad and Tobago since present disposal techniques presents environmental and health challenges. The results of this study investigating the influence of PET and CR on the performance characteristics of the HMA2 pavement design using Trinidad Lake Asphalt (TLA) and Trinidad Petroleum Bitumen (TPB) filled an information gap as no previous studies utilizing these indigenous asphaltic materials exist. Existing information using asphaltic materials other than TLA and TPB are irrelevant as variations in performance characteristics due to the addition of polymeric additives can vary from asphalt to asphalt due to differences in source and chemical composition of the parent binder. The results of this study show that a 6% CR and PET addition achieved the highest performance advantage demonstrated by an increase in the Marshall Quotient of between 21–22% and an insignificant decrease in the Bulk Specific Gravity (0.2%) compared to the unmodified blend. The improvement in the mechanical properties and the performance of the modified pavement materials observed is evidence of the useful effects of these waste materials in road paving design and offer a beneficial strategy for the reuse of these waste materials.