大井川徒渉制を中心とする近世・東海道の渡河形態について

抄録

There were three kind of river-crossing styles-wading, ferrying, and bridges-along the Tokaido (an old trunk road) in the Edo era. the reason why the difference among three styles was occured has not been discussed very much, though many researchs was done on each style individually.It is generally accepted that the Oigawa wading system has been developed under the military purpose of defending an old capital Edo, or under the political purpose of supporting relay stations. However, it can be pointed out that both technical and socio-economic factors affected even more significantly in the process of each river-crossing style formation.
As for tecnical considerations, river bed slope, depth of water, and geological feateres, and others have come to confirm the difference of rivercrossing styles.
As for the socio-econdmic considerations, the formation of the wading styles was inferred through assessment with the number of days forbidden to wade, the fare system depending on the depth of water, and the fare system of other river-crossing styles. Nevertheless, the wading system itself is assumed to be economically irrational. From the economic point of view, it is analysed that due to a small number of passengers at that time, constructing the long spanned bridge was uneconomical.