According to neo-classical economics, people make rational decisions based on costs and benefits, and a monetary value can be ascribed to each aspect of the decision-making process. These social cost-benefit analyses and the models associated with them have long influenced projects and policy appraisal in transport. But are they really accurate in their assessments?

Youth_on_train_tracksThe problem is that people are not always perfectly rational and their decisions are not always based on straightforward cost-benefit trade-offs. For instance, people have been shown to react to seemingly irrelevant information, and to be sensitive to social pressures. Yet four-step models based on neo-classical thinking continue to be the models predominantly used to understand the decision-making process. There do exist other models that better reflect the complexity of people’s thinking, such as hybrid choice models and activity-based models. Hybrid choice models include non-rational elements in the decision-making process, such as habit, ignorance, beliefs, attitudes and social norms. Activity-based models are based on the activities for which trips are made and can therefore reflect, to give one example, the constraints of family life on the mobility decisions of individual household members. Yet, as explained in A survey of transport planners, four-step models remain the models of choice for transport decision-making.

Behavioural economics tries to give a more holistic picture by looking at how people are affected by contextual elements in their decision making and how peer pressure affects their behaviour. It is also remarkably difficult to change habits and so the best time to nudge people towards behavioural change is when they are already going through some kind of transition such as a job change, getting married or having children. That said, this reluctance to change could be mitigated somewhat by dependable, multi-modal travel information, which would give travellers an array of options that they otherwise might not be aware of. This and other changes to today’s mobility will require new theories and new models that are capable of analysing mobility decisions in all their complexity. The MIND-SETS approach, guidelines and Knowledge Centre, will offer insights that could potentially pave the way towards these new theories and models.

For more information, contact Laurent Franckx of VITO