A modified wheel tracker testing method is used to understand better the rutting failure of flexible pavements made of Hot Mix Asphalt (HMA). Flexible pavement rutting is one of the most noticeable pavement distresses worldwide when subjected to traffic load and is a significant safety concern to transportation agencies because it affects the handling of vehicles. Asphalt slabs or cylindrical cores are typically inserted into a steel container and tested in this manner. As a result of this research, a new wheel tracker test rig was developed and constructed to measure the material's response to the load applied accurately. This study aims to analyze the influence of various aggregate gradient percentages and test the rutting resistance of asphalt mixtures using modified wheel track equipment. The experiment included hot mix asphalt samples with aggregate gradations up to 19 mm and three different aggregate sizes.