Significant changes have occurred affecting the complexity, scope, and context of transportation planning. Transportation planning tools have evolved and proliferated, enabling improved and more flexible analyses to support decisions. The default data and parameters used in travel demand models needed to be updated to reflect the planning requirements of today and the future, and updated guidance on travel demand forecasting procedures and their application for solving common transportation problems is necessary. The guidebook addresses the application of simple, straightforward techniques, optional use of default parameters, and appropriate references to other more sophisticated techniques. There are two primary ways in which planners can make use of this information: Using transferable parameters in the development of travel model components when local data suitable for model development are insufficient or unavailable, and checking the reasonableness of model outputs.