Gravity models, which estimate traffic flows between transport zones (determined by the Korea Transport Institute and similar to administrative TL4 areas), while accounting for local characteristics, should be used to estimate traffic volumes between the areas affected by the new infrastructure, including adjacent zones that are not directly affected. To account for expected changes from other projects, the constructor should review current national or regional plans for land use, transport, and industrial complexes. Based on these plans, the constructor should estimate the basic traffic volumes that are expected to result from the plans’ projects.