Tripmaker choice behavior for shopping trips under real-time information: Model formulation and results of stated-preference internet-based interactive experiments

This paper examines behavioral responses of non-commuters under real-time information during shopping trips. Utilizing results from an interactive stated-preference internet-based survey, discrete choice models are developed to investigate factors that influence en-route switching to alternate destinations and alternate routes. The fundamental difficulty in modeling this phenomenon is due to the manner in which information is provided to assist trip-making. The information provided and user choices are interdependent. That is, the choice set presented to a tripmaker at a decision state is predicated on his/her previous decision. Conversely, a tripmaker's decision in turn alters his/her information and choice sets. A model structure is formulated to overcome this difficulty. It explicitly captures the conditional nature of the decision process. The developed model provides insight on en-route diversions during the shopping trip together with the factors affecting these decisions, especially with regard to the role of real-time information.