The bicycle has achieved a new, central role in promoting environmental sustainability. The bicycle is conceived as a viable alternative to the car on short trips in particular, and the more the population shifts their journeys from car to bicycle the better, not least from a health and environmental point of view.This is the political background for announcing a national cycle city of Denmark. For the period 1999-2003 Odense has been established as a laboratory for demonstrating the potential of the bicycle in urban areas. Through campaigns, precautions for bicycle traffic, tax adjustments, more and better bicycle tracks, etc. the aim is to implement the bicycle at the expense of the car. The present Ph.D. study is focused on cyclists and their perceptions of health and nature. Within transport science several studies in everyday cycling have shown a correlation between transport habits, age, gender and mobility but in broader perspective it still remains unclarified what interdependencies exist between cyclist and perceptions of health and nature. It is an assumption that knowledge of these interdependencies is important in understanding why some people choose to bicycle and some do not. Therefore the project will combine theoretical and empirical material used in transport science with a sociological-humanistic approach.The empirical framework of the present project consists of a longitudinal questionnaire with 700 respondents together with qualitative research interviews.