Breaking commuter mode-use habits: An exploration of deliberative decision-making windows and their implications for travel demand management

Abstract

It is widely accepted that travel behaviour can be habitual. It is also widely accepted that voluntary Travel Demand Management (TDM) seldom records city-wide mode-switching impacts. If travel choices are habitual, this is unsurprising, as much of the population are not making deliberative choices, and new information is not considered. Shifts to deliberative choice-making are posited to occur when a ‘stressor’ (e.g., changing job location) is experienced, which renders the travel habit no longer satisfactory. A common conceptualisation of these moments is that the stressor triggers deliberation, manifested in information-seeking and experimentation, to find a new satisfactory behaviour. If found and implemented, a new habit may be formed. This conceptualisation has implications for improving TDM impacts. It is tempting to assume that voluntary TDM measures should target those who have just experienced such stressors, as they are likely to be most receptive to deliberative change. This paper reports the findings of a retrospective survey of a purposive non-probability sample of (n = 250) Cape Town commuters who had experienced a habit-breaking stressor. A recall aid in the form of an ‘event history calendar’ was used to help create multiple memory recollection pathways of past commuting behaviour, and a ‘deliberation calendar’ was used to guide respondents in reporting the process of habit breaking. The study found that the trigger for deliberation and information-seeking was not the manifestation of a new residence or job location (together accounting for the majority of observed stressors), but around two months earlier when the decision-maker consolidated a plan of action. This finding contributes to a growing literature on the temporal dimensions of behaviour dynamics, and has implications for how TDM should be targeted. Targeting new homeowners or employees misses the ‘window of opportunity’ to influence deliberative decisions and new habits. These decision-makers need to be targeted sooner, while still house- or job-seekers.