The San Francisco Model in Practice: Validation, Testing, and Application

Abstract

The San Francisco County Chained Activity Modeling Process (SF-CHAMP) was developed for the San Francisco County Transportation Authority (SFCTA) to provide detailed forecasts of travel demand for various planning applications. These applications included developing countywide plans, providing input to microsimulation modeling for corridor and project-level evaluations, transit planning, and neighborhood planning. The objective was to represent accurately the complexity of the destination and the temporal and modal options and to provide detailed information on travelers making discrete choices. These objectives led to the development of a tour-based model that uses synthesized population as the basis for decision making rather than zonal-level aggregate data sources. Most of the tour-based model’s nine components were estimated by means of household survey data for San Francisco, California, residents only that were collected by the Metropolitan Transportation Commission (MTC). Each model component was calibrated by using various observed data sources, and then the full model was validated with traffic count and transit ridership data for each of five periods. The model is applied as a focused model that combines trip making from the entire Bay Area (derived from the MTC’s BAYCAST trip tables) with the travel demand from San Francisco residents produced by the tour-based model.