Modified bitumen polymer dispersion (PDF) is applied in asphalt or bitumen modification processes by blending it with the base bitumen to enhance its properties. The PDF is typically mixed at elevated temperatures, allowing for a uniform dispersion of polymers throughout the bitumen matrix. This modification improves the elasticity, temperature resistance, and overall durability of the asphalt, making it suitable for high-stress applications. The resulting modified bitumen exhibits superior performance in various environmental conditions.