San Francisco County Transportation Authority
Moving the City

The Authority is home to SF-CHAMP, the official travel forecasting tool for San Francisco. SF-CHAMP is a state-of-the-art, activity-based model that predicts future travel patterns for the city. This tool is used for many Authority planning studies and projects.

About the SF-CHAMP Model

The San Francisco Chained Activity Modeling Process (known as SF-CHAMP) is a computer-based tool that can be used to assess the impacts of land use, socioeconomic, and transportation system changes on the performance of the local transportation system. SF-CHAMP was developed to reflect San Francisco’s unique transportation system and socioeconomic and land use characteristics. It uses San Francisco residents’ observed travel patterns, detailed representations of San Francisco’s transportation system, population and employment characteristics, transit line boardings, roadway volumes, and the number of vehicles available to San Francisco households to produce measures relevant to transportation and land use planning. Using future year transportation, land use, and socioeconomic inputs, the model forecasts future travel demand.

The San Francisco Model incorporates a state of the art approach to forecasting travel demand. This activity-based model is more sensitive than traditional four-step models to a broader array of conditions that influence travelers’ choices. One of the fundamental differences between the San Francisco Model and traditional models is that it is tour-based not trip-based. A tour is a chain of trips made by an individual that begins and ends at home without any intermediate stops at home, whereas a trip is a single movement from an origin to a destination. As such, the model structure is more complex than the traditional four-step modeling approach.

Find out more about our Model Service Bureau and Cycletracks, our iPhone and Android apps for recording and mapping real-time bicycle trip routes.

PUBLICATIONS

• "A GPS-based bicycle route choice model for San Francisco, California" (PDF)
• "Bicycle Route Choice Data Collection Using GPS-Enabled Smartphones" (PDF)
• "Exploring Parking Pricing for Congestion Management using the SFCTA Activity-based regional pricing model" (PDF)
• "Evaluating Regional Pricing Strategies in San Francisco-Appliciation of the SFCTA Activity-based regional pricing model" (PDF)
• "Application of a Travel Demand Microsimulation Model for Equity Analysis" (PDF)
• "The San Francisco Model in Practice" (PDF)
• "Systematic Investigation of Variability due to Random Simulation Error in an Activity-Based Microsimulation Forecasting Model" (PDF)
• "Analysis of New Starts Project by Using Tour-Based Model of San Francisco, California" (PDF)
• "Modeling Time-of-Day Choice in Context of Tour- and Activity-Based"
• "Development of Microsimulation Activity-Based Model for San Francisco: Destination and Mode Choice Models"

SF-CHAMP has also been profiled in "Modeling Time-of-Day Choice in Context of Tour- and Activity-Based Models" from the National Cooperative Highway Research Program's Synthesis 406: Advanced Practices in Travel Forecasting.

OTHER MODELS IN USE AT SFCTA

The Authority has recently been using a technology called Dynamic Traffic Assignment to allow planners to have a more fine-grained view of system performance as well as how traffic routes itself and why. DTA is a mesoscopic simulation of both autos and transit vehicles and has been piloted with a few projects at The Authority in the northwestern subarea of the City. The Authority recently obtained a grant from FHWA to expand the DTA model to cover the rest of the City and is actively working on this as an open source DTA research project. For a deeper understanding of dynamic traffic assignment and how it can be useful to planners, please read:

• "A Primer for Dynamic Traffic Assignment"
• "Regional Dynamic Traffic Assignment for Real World Travel Demand Models—Trying it out in San Francisco"