Life-cycle Assessment-based Environmental Impact Estimation Model for Earthwork-type Road Projects in the Design Phase

To encourage environmentally friendly construction, reasonable data (such as Life-Cycle Assessment (LCA) performance results) that determines the potential environmental impact of construction works should be provided during the decision-making process in the early design phase. However, it is difficult to acquire the data necessary to carry out an LCA prior to completing the design, so LCA is not typically used in the design phase. In order to overcome this limitation, this study developed an LCA-based environmental impact estimation model that uses the information available during the design phase to provide an estimate of the environmental impact of an earthwork-type road project. Earth, drainage, and pavement were defined as major work categories that have a significant effect on environmental impact and were accordingly made the focus of the developed model. The impact of the earthwork category was determined by case-based reasoning methodology, and the work quantity methodology using standardized cross sections was used to determine the impact of the drainage and pavement categories. Test results indicate that the proposed model provides a mean absolute error rate of 8.20%, demonstrating that it is valid and offers significant benefits for the early project estimation of environmental impact.