Depletion of natural resources for construction material, abundant generation of industrial wastes, disposal problems and their environmental impact have resulted in a continuous research scope for reuse of industrial wastes for sustainable engineering practice. Among these practices, the utilization of industrial wastes from metal processing industry for pavement subgrade stabilization has gained significant global importance. Present research aims at investigating the potential of one such material zinc slag (ZS) in altering and enhancing the strength properties of black cotton soils (BCS) for possible pavement applications. Different dosages of ZS (25, 50 and 75%) and cement (3, 6 and 9%) are administered to the black cotton soil. The mechanistic performance of these stabilized soil–slag mixtures in the form of CBR and unconfined compressive strength (UCS) values has been observed and used as an indicator to investigate the suitability of these mixes as pavement subgrade and subbase roads having traffic intensity up to 5 msa. The proposed layer thicknesses due to the increased CBR/UCS values is calculated to meet the IRC: 372018 guidelines. The IITPAVE analysis is used to quantify the fatigue and rutting strains at perilous locations in the pavement during the desired service life.