This research presents an investigation on the incorporation of atactic polypropylene (APP) as a modifier in bitumen at weight concentrations from 0 to 30 wt%. An APP-modified bitumen (APPMB) was prepared by conventional, hot, and in situ blending and characterized for mechanical, morphological, thermal, structural, and physical properties. APPMB specimens using maleic anhydride (MA) functionalized polymer at its optimized concentration of 20 weight percentage (wt%), along at several other concentrations, were pre-