In Long Term Pavement Performance (LTPP) assessment process , the specific pavement studies were designed to investigate the factors affecting pavement rehabilitation such as overlay thickness (51 and 127mm), asphalt overlay materials (raw compared with adding 30% reclaimed asphalt pavement (RAP)) and surface curing type before rehabilitation (low and heavy). In this study, data from 4 sites were taken to perform analysis where each site consists of 8 sections (4 sections with raw materials and another 4 sections using 30%RAP). Each section was 152.4 m long and 3.66 m wide. These sites were selected due to their similar climate to Egypt. Four performance indicators were chosen including fatigue cracking, longitudinal cracking, rutting, and roughness. A statistical analysis using the paired t-tests, p-values and analysis of variance (ANOVA) were achieved to determine the priority in performance and the significance in variation. The results that based on practical observations have indicated that the RAP sections achieved similar/ better performance as compared with raw sections especially at higher thickness except for rutting. The climate had no obvious effect on fatigue cracking development while dry climate provided higher longitudinal cracking and roughness progress for RAP sections. Statically, the variation in pre-overlay curing (from low to heavy) had the highest statistical effect on fatigue cracking increasing, while rutting and roughness progresses weren't clearly affected by variation in climate, thickness or curing.