Coastal areas are ideal settings for both individual and commercial real estate projects, as well as the infrastructure that supports them. Coastal and offshore structures, on the other hand, are sensitive to the effects of seawater on their foundations. Seawater contains a variety of salts that can harm civil engineering structures. The majority of India’s highways are flexible pavements, which carry the majority of the country’s passenger traffic. As a result, predicting the appropriate thickness of pavement layers (bituminous and granular layer) are necessary to safeguard the pavement from rutting and cracking for weak and strong subgrades for low and high-volume roads. This paper describes the use of locally available self-cementing Class C fly ash at a concentration of 20% to stabilize saline soil in the Bhavnagar area of Gujarat and broaden the scope of pavement design and analyze them with the IITPAVE software. Unconfined Compressive Strength and durability was performed to see the efficacy of fly ash on saline soil.