Transferability: How to Make it Work Best for Your Model (February 19, 2015)


Date: February 19, 2015

Description:  The mathematical relationships in travel models depend on parameters that reflect the sensitivity of travelers' choices to the model's input variables. The process of model transfer from one region to another has become commonplace as a way to obtain model parameter estimated when sufficient local data for model estimation are not available. This webinar will provide guidance to transportation planners on alternative approaches to model transfer based on the amount of available resources. The guidance is based on research that has been conducted on model transferability, which indicates mixed results for model transferability.

The focus of the webinar will be on specific ways in which modelers can choose the best methods and practices for transferring model parameters given the types of models and data available. Planners in many cases may have superior alternatives to the use of national average parameters, especially when some local data are available. Transferability results may be improved through use of small amounts of local data in an updating process when transferring models. This webinar seeks to present that knowledge to provide planners along with practical guidance in determining the best transfer methods for their unique situations. The guidance includes variable specification, model updating procedures using some local data, procedures to use when local data are unavailable, and use of data from national sources. Simple examples of the various model transfer methods will be presented.


Tom Rossi is a Principal at Cambridge Systematics, Inc. with over 30 years of experience developing, validating, and applying travel demand models. He has served as an expert advisor to Federal agencies and MPOs for the development of travel models and survey data collection efforts. For over 20 years, Mr. Rossi has worked with the U.S. DOT to conduct research, to prepare reference documents, and to develop and teach training courses in travel demand modeling. He has served as the Principal Investigator for several transportation research projects, including SHRP Project C10 to develop an integrated, advanced travel demand model and the development of NCHRP Report 716, Travel Demand Forecasting: Parameters and Techniques. Mr. Rossi is the past chairman of the Transportation Research Board's Transportation Demand Forecasting Committee. A very long time ago, when it was easier to gain admission, Mr. Rossi went to a university and earned some degrees.

Dr. Chandra R. Bhat is the Director of the Center for Transportation Research (CTR) and the Adnan Abou-Ayyash Centennial Professor in Transportation Engineering at The University of Texas at Austin, where he teaches courses in transportation systems analysis and transportation planning. Substantively, Bhat has contributed to the area of transportation and urban policy design, with far reaching implications for public health, energy dependence, greenhouse gas emissions, and societal quality of life. Methodologically, he has been a pioneer in the formulation and use of statistical, econometric, and mathematical modeling methods.