Abstract
Urban communities face various problems in relation to traffic movement. In particular, the City of Sapporo must deal with the critical issue of urban traffic congestion caused by snowfall. During winter, travel speeds are remarkably reduced, which causes traffic congestion. To determine the priority of snow and ice control operations, it is necessary to understand changes in traffic patterns over a long period throughout the city. This study examined variations in travel speeds using taxies as ITS probe vehicle. The results enable determination of time loss caused by traffic congestion and the priority of snow and ice control operations.