Significant research advancements have been made in the optimization area for minimizing construction time and cost. There has been little or no reported research focusing on multi-objective models for optimizing construction time, cost, quality, and environmental trade-off optimization in highway construction projects. Project time and cost are effective criteria which should be taken into consideration in addition to quality and environmental impact during planning phase. The problem is how to select the best construction plan based on taking the effect of time, cost, quality and environmental is considered a crucial issue. The developed model in this research is formulated to transform the traditional two dimensional time-cost trade-off analysis to an advanced four dimensional time-cost-quality-environmental trade-off analysis. To minimize the cost, time and pollutants generated with maximizing the execution quality for highway construction project, construction engineers and planners need to analyze and optimize their resource utilization decisions and selections. For each activity in the project, these decisions include: a) selecting construction methods and raw materials, and b) identifying equipment's and labors crews’ configurations and size. For example, using green materials decreases air pollution, but it often increase cost. Similarly, other resource utilization decisions have a direct impact on project time, cost, quality and pollution. Mathematical programming models were utilized to optimize the trade-offs between construction time and cost in many studies. However, the application of these models is limited as they aren't efficient in optimizing large-scale construction project. Genetic algorithm models were applied in this research to optimize time-cost- quality-environmental trade-off highway construction project.