Trip generation modeling using data collected in single and repeated cross-sectional surveys.

SUMMARY The majority of US metropolitan regions still use the four-step urban transportation modeling system to develop their travel forecasts. Trip generation, the first step of this system, has as objective of predicting the expected total travel demand in a region. The commonly used methods in planning practice for predicting this expected total travel demand typically use only the most recent cross-sectional data available from a study region for model development, which ties the resulting travel-forecast model to the economic environment prevailing at the time of data collection. Applying such models to generate forecasts of travel in economic environments significantly different from those embodied in the estimated model parameters could result in greater errors than would otherwise be the case. To address the aforementioned problem, this paper proposes the development of trip generation models estimated on multiple independent cross-sectional datasets collected in the same urban region but at different times representing different economic environments. Data used in the research were collected in cross-sectional household travel behavior surveys undertaken in the Greater Toronto Area, Canada in 1986, 1996, 2001, and 2006. The results lead to the conclusion that well-specified models, estimated on pooled multiple cross-sectional datasets, yield travel predictions in the base and horizon years, respectively, that have smaller error compared with corresponding travel predictions generated with single cross-sectional models. Copyright © 2012 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]