How is Model Accuracy Improved by Usage of Statistics?

摘要

This paper shows how important the use of statistics in Asian transport is for the model calculation in order to evaluate impacts of the policy to improve the environment of international freight transport. How the model accuracy is improved if some statistics are available in the model calculation, and how different the impacts to the model accuracy are discussed according to the type of available data used, especially from viewpoints of “detailed zoning” and “usage of more realistic data”. As a result, it is found that “detailed zoning” enhances the model accuracy. On the other hand, the impact of “usage of more realistic data” on worldwide international cargo flow is limited, but it is as significant as that of “detailed zoning” on international cargo flow crossing national border by land. It is also found that both of them bring significant differences when evaluating policy effects such as infrastructure investment and alleviating barriers of national borders.