Changes of private car use in response to travel demand management

A conceptual framework based on self-regulation theory in social psychology is proposed with the aim of understanding changes of private car use in response to travel demand management measures. Such measures are assumed to start a process in car users of setting of car-use reduction goals followed by planning of how to implement and implementing changes in car use to reach these goals. It is hypothesized that choices among change options are made sequentially according to a satisficing principle of minimizing psychological and other costs. As implied by an operationalization of this hypothesis, results of surveys indicate that choices of mode switching correlate the strongest with the size of the car-use reduction goal, errand/trip suppression the next strongest, and efficient car use (trip chaining, car pooling, and choice of closer destinations) the weakest. Modification of the hypothesis is implied by the findings that these correlations are to some extent affected by trip purposes (work, shopping, and leisure) and socio-demographic factor