RECENT EXPERIENCE WITH ACTIVITY AND TOUR-BASED REGIONAL FORECASTING MODELS FOR MPO PLANNING

This paper provides an overview of recent experience in developing new activity and tour-based models for regional travel demand forecasting by Metropolitan Planning Organizations (MPO's) in the United States. It highlights both the advances / benefits of tour-based models, with a focus on the most recently implemented model of this type developed for the Mid-Ohio Regional Planning Council (MORPC), as well as provides a discussion of some of the development challenges and issues that MPO's should consider when upgrading their modeling capabilities. These more behaviorally realistic models are contrasted with the conventional aggregate modeling systems in terms of model structures and properties, advantages for planning forecasts, and their data and other implementation requirements for development by MPOs. The new generation of regional travel demand models is characterized by three base features: 1) an activity-based platform, that implies that modeled travel be derived within a general framework of the daily activities undertaken by households and persons, 2) a tour-based structure of travel where the tour is used as the base unit of modeling travel instead of the elemental trip, and 3) micro-simulation modeling techniques that are applied at the fully-disaggregate level of persons and households, which convert activity and travel related choices from fractional probability model outcomes into a series of crisp decisions. The experience to date with the development and implementation of activity/tour-based modeling in the United States described in this paper points to a broader acceptance and implementation of the new models by MPOs over the next several years.