Improvement Planning of Winter Road Network in the Tohoku District

SYNOPSIS In snowy areas, a lot of roads are closed due to heavy snowfall in every winter season. Some roads may be located on important routes for social and economic activities during non-snow seasons in these roads. Therefore, it is necessary to establish the rational improvement method of road networks to ensure the regional traffic in these areas. In this paper, the author proposed the practical method on priority level for the improvement planning of the winter road network taking the possibility of using roundabout into consideration. Furthermore, the author applied this method to data on road traffic closure in the Tohoku District and examined the efficiency of the system.