Abstract
Travel demand forecasting is generally performed using a zoning and network system. These two elements are closely connected with each other, and the aggregation levels of them should be determined appropriately depending on the purpose and subject of research. The purposes of this paper are to analyze interactions of aggregated zoning and network systems and to propose a method minimizing spatial aggregation errors stemming from aggregated zoning and network systems. Statistical reliability tests are performed to assess the fitness of the proposed aggregation levels. The results show that the two proposed aggregation levels can make traffic assignment results within a reasonable error range and also reduce required time and costs significantly. The results of this study are expected to contribute to a methodology for proposal and preliminary feasibility studies and then to provide an objective and rational basis for the project promotions.
