Marine traffic engineering is a new field of navigation study with a history ranging over some fifteen years. The first traffic survey fully deserving of the name was carried out by Yamaguchi et al in 1963 in Japan; more than 30 surveys a year are nowadays being carried out with the cooperation of the Maritime Safety Agency, the Japanese Association for Preventing Sea Casualties and the Marine Traffic Engineering Research Group. The number of papers on the subject in the Journal of the Japanese Institute of Navigation has increased correspondingly. Table I gives a breakdown of theoretical studies of marine traffic engineering. A general account of Japanese activity in these fields has been published in different papers in the Journal of Navigation, London, and emphasis in this paper is based on activities since 1970.