An Economic Loss due to Bottlenecks for Domestic Automobile Transportation of International Maritime Container Cargos in Japan

Abstract

In Japan, vehicular transportation by semi-trailers and similar means accounts for more than 95% of total domestic transportation of international maritime containers. Restrictions are being eased for heavy containers with gross weights exceeding the general limit values specified in the Road Structure Ordinances and high-cube containers with a height of 9'6. However, Japan still faces many traffic-related problems originating in the poor road environment of the country. To realize efficient transportation of international maritime cargos, it is necessary to implement effectively infrastructure construction projects which consider the linkage between ports and roads. Therefore, it is necessary to clarify actual conditions in the domestic flow of international maritime cargos and port selection behavior and construct a transportation route/shipping (or landing) port selection model for international maritime cargos which also considers road bottlenecks, such as narrow roads, outdated bridge and tunnel specifications, tight curves, etc. impassible to large vehicles. Including the models developed previously by the authors (Ieda, et al., 2000 and Watanabe, et al., 2000), none of the shipping/landing port selection models or transportation route selection models developed thus far, or analyses of the current condition of hinterland transportation (for example, Watanabe, et al., 1989) and road traffic features in coastal areas has considered bottleneck problems affecting large vehicles such as semi-trailers. As one exception, a Japanese Ministry of Construction (2000) study attempted to quantify the effect of eliminating bottlenecks, but this work must be considered inadequate, such as the study included only high-cube containers and the method of establishing transportation routes was arbitrary. Moreover, because virtually no other country has as many physical restrictions on land transportation of international maritime containers as Japan, little research of this type can be found outside Japan. This paper therefore investigates the effect of bottlenecks in the Japanese road transportation network, considering international maritime containers as a representative international maritime cargo. First, the current condition and system of traffic restrictions on vehicular transportation using semi-trailers, which accounts for the majority of domestic transportation of such containers, is summarized. Bottlenecks in the actual transportation network are then extracted, and the economic loss due to detours around these locations are calculated.