Using Taxi GPS to Gather High-Quality Traffic Data for Winter Road Management Evaluation in Sapporo, Japan

How can we increase the quality of traffic data to provide effective and efficient winter road management in the City of Sapporo? In Sapporo, not only residents ’ daily activities but also business and industrial activities depend heavily on automobile mobility. The not-enough winter road management is, however, the critical problem: it leads to worsen traffic movement through the City. The problem is not simply that travel speed is remarkably reduced as a result of icy roads and street width narrowed by snow pile. The problem is that slowing traffic speed down leads ever-worsened traffic congestion as shown in Figure 1; consequently, it results in economic losses and air pollution. A primary goal of our study is to identify the effective and efficient traffic data gathering technique in order to develop winter road management measurement that might be implemented in the context of Sapporo. Throughout the course of this study, we have attempted to demonstrate how the cutting-edge technology has the potential to help solve the problems with existing traffic analysis methods and increase the quality of data to determine the unique traffic feature in winter. The cutting-edge technology we are interested in is “floating-car data ” collected through putting Global Positioning System (GPS) on “taxis ” running through the City. Because of its advantage covering the great Sapporo area and running throughout the day, this would enable up-to-date traffic data to be supplied over a wide area. Besides, “partnership ” with taxi-companies provides cost-effective data collection solutions. BACKGROUND The City of Sapporo is the prefectural capital of Hokkaido, the northernmost island of Japan, and is Japan’s fifth largest city with a population of approximately 1.8 million in 2003. The City is located on latitude 43 north and longitude 141 east, and cities at roughly the sam