<p>Subgrade soil permeability is essential for effective pavement drainage, directly influencing the durability of flexible pavements. The current research investigates how industrial wastes viz. brick kiln dust and pond ash can be utilized, for enhancing the permeability of the clay and sand subgrades. Various proportions (10%, 20%, 30%, and 40%) of these stabilizers were tested both individually and in combination. Results show that the permeability of clay increases consistently with higher stabilizer content, improving drainage. While in the sand, permeability initially decreases at 30% stabilizer content but increases with further additions. Despite the initial reduction, the stabilized sand maintains a drainage performance equivalent to well-drained soils. These findings demonstrate that both these wastes are capable of being utilized to increase subgrade permeability, which will improve drainage and cause flexible pavements to last longer. The current investigation highlights the effectiveness of these industrial by-products for more sustainable and eco-friendlier pavement construction.</p>