Bituminous concrete (BC) courses are crucial for flexible pavements, providing durability, stability, and a smooth riding surface. The performance of these courses is significantly influenced by aggregate characteristics. This study critically reviews the impact of aggregate gradation on BC mix properties. By examining existing pavement structures and mix designs, the study identifies how different aggregate sizes and distributions affect overall performance and longevity, proposing new gradations to enhance mix properties. Despite extensive research, gaps remain in understanding optimal aggregate gradation for various traffic and environmental conditions. Current specifications may not adequately address the needs of high-traffic and extreme weather conditions, leading to premature failures like rutting and cracking. Tests including Marshall stability, indirect tensile strength, and fatigue testing are used to evaluate mix properties. Results indicated that the proposed gradations improved Marshall stability values by 15–20% and increased indirect tensile strength by 10–12%. In terms of fatigue resistance, BC Proposed Grade I exhibited a 12.03% increase in cycle count, and BC Proposed Grade II showed a 10.29% increase compared to the MORTH grades. In conclusion, the proposed BC grades exhibit superior performance in tensile strength, moisture resistance, particle packing, and fatigue resistance, offering increased durability and reliability for road construction.