The findings are summarized as follows: (1) studded tyres are virtually not in use today; (2) environmental problems (vehicle-induced dust pollution) such as suspended particulate matter and dust fall were remedied; (3) abrasion of pavement caused by studded tyres was ameliorated and the repair cost for pavement overlay was lowered; (4) studless tyres facilitate the formation of slippery road surfaces, and very slippery road surfaces occurred when the studded tyres equipping rate approached 0 per cent; (5) slipping accidents increased during winter; (6) winter traffic conditions deteriorated; (7) the survey on traffic awareness revealed that most citizens recognized positive effects on the environment, but pointed out that they faced aggravated situations in terms of traffic congestion and safety issues in winter; (8) the results of cost-benefit analysis indicated that the regulation of studded tyres impose burdens on not only road administrations but also road users in the aspects of losses from increase in travelling time, travelling cost and traffic accidents; and (9) however, according to the general evaluation in the awareness survey, nearly half the respondents answered that the situations were improved from before, while unchanged and worsened combined to account for nearly half the total. Based on these results, it was difficult to conduct an accurate evaluation of the effects of studded tyres regulation. In the light of its highly evaluated effects on the environment, studded tyre regulation might be considered generally successful, and it is unlikely that studded tyres will come back into common use. Rather, it remains for certain issues to be addressed. The primary solution to these problems would be to develop a tyre that works effectively on frozen road surfaces without damaging the pavement. At this stage, however, it is impossible to produce such a tyre. On the other hand, lightweight studded tyres were recently developed in Nordic countries with the aim of reducing pavement abrasion. They do not affect pavement abrasion in the same way as heavy as former studded tyres. Effective use of such lightweight studded tyres may reduce occurrence of extremely slippery winter road conditions and thus their introduction would attract our considerable attention. Other some provisional solutions are suggested below. Approaches from the standpoint of technological development: (1) effective and efficient distribution of existing anti-freezing agents and anti-skid materials; (2) development of cost-effective and environmentally friendly anti-freezing agents and anti-skid materials; and (3) improvements in pavement structure, including freezing-prevention pavement and a low-cost road heating system. Approaches taking into consideration the effects of studless tyres on snowy and icy road surfaces: (1) use of studded tyres or chains (including non-metal chains) during the period when most roads within the city are covered with snow and ice (January and February in the case of Sapporo); and (2) allowing studded tyres and chains (including non-metal chains) for light motor vehicles, which do less damage to pavement, and public transportation such as buses on regular routes. Other: (1) promotion of intra-city comprehensive traffic measures including the Traffic Demand Management (TDM).