The multiple benefits of active transportation, from non-communicable disease prevention to climate change mitigation, have led to increasing interests in developing multi-disciplinary health impact assessments (HIA) of walking and cycling strategies. However a fundamental uncertainty regarding the effectiveness of policies to change travel and physical activity behaviour remains. Our study aimed to assess the ability of bike sharing programs to facilitate contemplation and change in individuals to begin cycling for travel purposes. Methods: Participants living and working or attending school...