In order to support informed decision making, transportation agencies have been increasingly developing and experimenting with activity-based travel demand models that describe how people plan and schedule their daily travel. Activity-based models more closely replicate actual traveler decisions and thus may provide better forecasts of future travel patterns. While there have been recent successes implementing practical activity-based models, these have been limited mostly to larger metropolitan planning organizations (MPOs) and a few state departments of transportation (DOTs). This guide has been developed to help directors, managers, and planners make informed decisions about forecasting model development and application. The guide is composed of two parts. Part 1 is a primer intended to provide a practical overview of activity-based model development and application. Part 2 discusses issues in linking activity-based models to dynamic network assignment models. The fi rst part comprises three chapters. The fi rst chapter is for managers or directors who make decisions about what travel demand models an agency will use and begins with a brief introduction to the motivation and practice of developing and applying travel models. Chapter 1 also provides a pragmatic assessment of activity-based model development considerations, both technical and institutional, and examines how activity-based models are integrated with other forecasting tools. The second chapter provides a technical road map for developing an activity-based model system for modeling or planning managers. Chapter 2 identifies development strategies that agencies have used and discusses each aspect of the model development process, including • designing the modeling system to address key policy considerations; • specifying temporal, spatial, and typological resolutions; • identifying activity-based model subcomponents and the relationship between the activity-based model and other forecasting tools; • developing data; • implementing the models and model system linkages; and • applying the model system. The third chapter presents and explains key activity-based model concepts. The intended audience for this section is modelers who have some familiarity with traditional trip-based concepts. The demand-and-supply model framework is examined, discrete choice models are explained, and activity-based concepts are presented. The second part is a discussion of issues in adopting integrated dynamic model systems. The purpose of this element is to examine the benefits, barriers, and practical issues that MPOs, state DOTs, and other transportation agencies face in migrating from traditional to advanced travel demand forecasting models in which activity-based models are linked with regional-scale dynamic network assignment models. This information is included in the activity-based model primer because activity-based models are a core component of integrated dynamic model systems, and developing and applying dynamic model systems is an area of significant emerging research and practice. (Author/publisher)
Samenvatting