Activity-Based Travel Demand Modeling: Progress and Possibilities

In the past three decades, activity-based travel demand models have received much consideration and seen significant progress. Activity-based models of travel demand belong to the third generation of travel demand models and are based on the concept that travel is a derived demand, originating from the need of individuals to participate in activities. Activity-based travel demand models are able to better replicate travel decisions at the individual or disaggregated level, and may therefore yield better predictions of future travel patterns. The current paper presents a comprehensive overview of recent and ongoing computational-based activity scheduling models. For comparison, a brief account of aggregated trip-generation approaches to travel demand is also presented. The advantages of activity-based travel demand modeling, and a discussion of how such modeling may be applied in practice, are provided. Finally, some of the unsolved issues and directions for further research are identified.