Conditions of success in sustainable urban transport policy - Policy change in 'relatively successful' European cities

The paper outlines some preliminary results of an ongoing study on 'conditions of success in sustainable transport policies in cities'. The study consists of a comparative analysis of five case studies dealing with relatively successful European cities in three countries: Zurich, Basle (Switzerland), Amsterdam, Groningen (The Netherlands) and Freiburg (Germany). Having in mind the ongoing deterioration of traffic-related environmental problems in cities, the paper proceeds in a three-step approach: by describing the trends of transport of persons and the environment in general and of forerunner cities in particular, the opportunities and limits of sustainable urban transport developments are detected in a first step. In a second step, the degrees and patterns of environmentally oriented policy changes in relatively successful cities are outlined. The third step focuses on the reasons and ways policy windows open up for fundamental environmentally oriented changes of transport policies. It is argued that 'macro-windows' for such changes only open up due to strong and enduring forces originally from outside the local political system. Social crises and impressive political mandates were identified as important external factors that influenced the 'greening' of urban transport in the relatively successful cities. However, an open macro-window is only conceived as a political opportunity for change, a necessary but not sufficient condition. Whether or to what extent these opportunities are utilized depends on further factors.