Interrupting habitual car use: The importance of car habit strength and moral motivation for personal car use reduction

In this study, habitual car use was interrupted by means of an intervention attempting to induce a deliberate consideration to reduce personal car use and forming implementation intentions for the planned changes in travel behavior. The importance of car habit strength and of moral motivation for reducing car use was analyzed. The study was conducted as a field experiment where 71 car users were recruited to either an experimental group or a control group. All participants reported car habit strength and moral motivation to reduce car use (i.e. personal norm) by means of a questionnaire, and recorded car use by means of weekly car diaries pre- and post-intervention. Results demonstrate that the intervention did make the choice of travel mode more deliberate since the association between car use and car habit strength were weakened while the relation between car use and personal norm were strengthened after compared to before the intervention. Moreover, as a result of the intervention car users with a strong car habit and a strong personal norm were found to be more likely to reduce car use as compared to those with a weak car habit and a weak personal norm. Hence, a reduction in car use may be facilitated by interrupting habitual car use, specifically if the car user has a strong car habit and a strong moral motivation to reduce personal car use.