The habitual action perspective suggests that where transport users have strong travel choice habits, motivation will have no effect on behaviour. This has commonly been demonstrated in situations where travel habits and intentions conflict, but in stable decision settings intentions and habits will correspond. This paper reports two studies which demonstrate the moderating effect of habit on the intention–behaviour relationship within established commuting contexts. Results illustrate how motivational accounts of travel behaviour may be misleading if statistical significance of correlational data is the main criterion for model acceptance. Alternative methods for theory testing are discussed, and strategies for disrupting driving habits reviewed.