Frost and snowfall prediction system

For effective road surface management during winter, the Nagano National Highway Work Office of the Ministry of Land, Infrastructure and Transport introduced the Frost and Snowfall Prediction System in March 1998.

Road surface temperatures for the following 48 hours are predicted at hourly intervals at 26 points on the roads by using data obtained from roadside frost sensors and meteorological data. In addition, the minimum and maximum temperatures, road surface conditions, and snowfall are predicted twice a day, everyday at 10:00 hours and 16:00 hours at five locations in the heavy snowfall area near the border between Niigata and Nagano Prefectures. The system offers an accuracy ratio of about 70 percent and can predict the minimum temperature and snowfall to an accuracy of Plus-or-minus 2degrees Centigrade and Plus-or-minus 2.5 cm, respectively. The system correctly predicted 87 out of 93 snow days in 2000, a success ratio of 94%.

These predicted figures are transmitted to five branch offices and several snow removal stations within the jurisdiction of the Nagano National Highway Work Office to help facilitate road management, and are used for organizing a snow removal system and for deciding on the call-out of snow removal teams.

[Nagano National Highway Work Office of the Kanto Regional Development Bureau, Ministry of Land, Infrastructure and Transport]

ITS HANDBOOK 2001-2002（Sep 2001）