Traffic congestion in big cities is a growing problem, and in the Swedish capital of Stockholm a seven-month long trial period with congestion taxes was carried out in 2006. It has since been made a permanent system. In this book, the authors scrutinise and analyse the political and administrative processes of the first Swedish congestion experiment and its aftermath. The articles point to the fact that traffic policies are implemented for varying purposes, and differing interests can be premiered when designing congestion systems. The authors' analyses are mirrored against collective, international experiences and research. The authors describe the preoccupations, hopes and impressions that came along with the trial period, and how feelings fluctuated among the inhabitants of Stockholm before, during, and after the trial. The book shows how research can and should follow the general trends in societal developments closely. Flexibility is especially important in order to explain problems, and preventing gossip and preconceived ideas from gaining a foothold. The authors hope to provide tools for avoiding the pitfalls, and that the successes of the Stockholm Trial will be repeated in other contexts.