Abstract
In Akita region along the northwest coast of Japan, about fifty tons of salt per kilometre of the highway is used to prevent the snow on the road surface from freezing every year. Reported in this paper is the estimate of the salt contamination in paddy fields adjacent to Akita Expressway. The speed of the travelling diffusion front of the possible saline ground water was estimated as low as 2 mm/year. In the paper, we also review the current operation of Akita Expressway in terms of snow removal and freeze prevention during the winter season.
