To reduce car usage, several strategies are needed, one of which focuses on social psychological factors. The aim of this study was to predict and explain bus usage using the theory of planned behaviour and the transtheoretical model of change in a sample of 983 residents. The study also evaluated the effect of providing a group of regular car users (n = 34) with a free travel pass, to be used on busses and trains in the region. A regression analysis showed that the theory of planned behaviour (TPB) explained 26% of the variance in intention to use the bus, increasing to 59% when past behaviour was added. The use of the free travel pass resulted in a more positive attitude towards bus usage, with a large number having either changed or having started to change their behaviour. When the same people were contacted three months later, 50% still used public transport. The conclusion is that negative attitudes and travel habits can be altered by experience. Although, a reduction of car use can only be achieved if several measures are implemented that make car driving less attractive and sustainable modes of transport more attractive.