Construction industry plays a major role in improving the socio-economic growth of any country. However, this industry is facing a serious problem of cost overrun globally and particular in Pakistan. Rapid growth in the construction sector in Pakistan has been observed along with many challenges, especially in highway projects. The most critical issues in highway projects are the cost overrun and lack of their mitigation measures. Hence, the objective of this research is to determine the critical factors of cost overrun, its significant mitigation measures and to develop a structural model of significant mitigation measures for critical cost overrun factors. The preliminary survey helped in identifying the critical factors of cost overrun in highway projects. In total, 64 common factors for cost overrun were identified from the literature review. Based on the common factors, a questionnaire was designed and distributed among the 30 selected experts to determine the critical factors of cost overrun. Out of 64 common factors, 24 were reported critical. The pilot study was carried out by developing a semi-structured questionnaire which was distributed among the same 30 construction experts for the purpose of determining the mitigation measures, which resulted in 113 measures. These mitigation measures along with the relevant 24 factors helped in the development of the final questionnaire to further narrow down the significant measures. This finalized questionnaire was distributed among 350 construction experts of highway projects to identify the significant mitigation measures for critical factors of cost overrun. The collected data was further used to develop a structural model for mitigation measures of critical factors of cost overrun by Smart PLS. Performance of the model has moderate explaining power as the predictive relevancy value is greater than 0.13. Significant mitigation measures of these critical factors were determined from the power loading of mitigations measures. This research would be helpful for construction managers in mitigating the relative risk to the project. Thus, it will directly benefit the construction community and contribute in raising the economy of the country
