Activity-based models take traditional models of travel demand a step forward by deriving the demand for travel from the demand for participating in activities. Although the concept of activity-based modeling is not new, manipulating it for full-scale transportation planning is not a trivial step. Prof. Shiftan has been one of the pioneers both in developing the models and in attendant methods to materialize those models, by creating practical tools for engineers and planners. In brief, he has been:
- The first scholar to develop trip-chaining models in the United States (Shiftan, 1998). This work has made a breakthrough in the development and application of activity-based models and the ability to model the complex relations among trips an individual makes through the day.
- One of the main contributors to the first full activity-based model demonstration (Bowman et al., 1999).
- The first to demonstrate the advantages of such models for policy analysis and air-quality purposes (Shiftan, 2000; Shiftan & Suhrbier, 2002).
- The first to analyze the trade-off between model complexity and behavior realism to make such models both practical and policy sensitive (Shiftan & Ben-Akiva, 2011).
- The first to use the activity-based paradigm to research the relationships between travel behavior and safety and to better analyze the risk of being involved in road crashes (Elias et al., 2010).
- An initiator and leader in the design of the new activity-based model for Tel Aviv, one of the first full-scale activity-based models used by a major metropolitan transportation-planning agency. This model is now used for all transportation-planning applications in the Tel Aviv metropolitan area (e.g., the planning of the new light rail system), making Israel a world leader in innovative travel demand models. Given the success of this model, Jerusalem is currently also developing such a model.
- Developing a new method of integrating the activity-based paradigm with land use and other long-term lifestyle decisions to improve our understanding of these complex relationships (Shiftan, 2008).
- Developing and teaching a new graduate course on the topic.