In the Sapporo metropolitan area, it is extremely important that the reliability and punctuality of winter road traffic be ensured, toward maintaining normal civic, social and economic activities. The Hokkaido Development Bureau and the Civil Engineering Research Institute carried out an ITS experiment in the Sapporo metropolitan area, with cooperation from the area's road administrators and other organizations and citizens. The experiment used advanced information and telecommunications technology including the Internet, and mobile terminals. The experimental Project consisted of the Road Information Sharing Experiment and the Car Commuter Monitoring Experiment. The Road Information Sharing Experiment aimed at developing systems for enhanced measures against snow and ice problems through coordination between organizations responsible for winter road surface management. In the experiment, attempts were made to share winter road information among road administrators, using an experimental model involving an extranet and an electronic mailing list. A post-experiment questionnaire survey of participants in the experiment revealed a strong recognition among them that the Internet-based technology used in the experiment could be extremely useful for realizing efficient information sharing among different organizations. In the Car Commuter Monitoring Experiment, weather and road surface information was distributed to car-commuting monitors who were advised, where appropriate, to use public transportation. The monitoring experiment was carried out as part of a larger review on appropriate ways to control winter traffic demand in line with current weather conditions toward alleviating traffic congestion. In the experiment in the winter of 2000/2001, road weather information was delivered to monitors via their Internet-accessible mobile phones. These monitors subsequently filled out a questionnaire to indicate whether the information provided affected their commuting behaviour in any way. The questionnaire indicated that accurate and timely provision of weather and road information could prompt road users to change from cars to public transportation and to exercise staggered commuting, all of which could be effective toward alleviating winter traffic congestion.