Abstract
Different widely accepted principles are used to determine the transport mode in which particular commodity is to be carried at the strategic planning level. One such rule is the commodity value-weight ratio. Discrete choice model is being employed in this paper using available macroscopic commodity trade information. The selection of appropriate data aggregation level for analysis is studied and its corresponding impacts are presented. By examining international commodity flows between countries, the modal split between air and sea transport are compared. After investigating four separate international trade routes and three trade data classification levels, it was found that aggregated trade classification data yields comparable results to detailed trade classification data. With respect to the Harmonized Commodity Description and Coding System, our analyses showed that for the purpose of mode choice studies at the planning level, it may be more efficient to develop models using HS two-digit commodity trade data.