Development and Application of the SACSIM Activity-Based Model System

This paper presents the latest information about the activity-based regional travel forecasting model system being implemented for the Sacramento, California, Council of Governments. The SACSIM model system represents travel in the context of an integrated disaggregate econometric model of each resident’s full-day activity and travel schedule. Sensitivity to neighborhood scale is enhanced through disaggregation of the modeled outcomes in three key dimensions: purpose, time, and space. Each activity episode is associated with one of seven specific purposes, and with a particular parcel location at which it occurs. The beginning and ending times of all activity and travel episodes are identified within a specific 30-minute time period. The model system has been calibrated and tested for a base year of 2000 and for forecasts to the years 2005 and 2032. The paper summarizes the model system structure, explains the integration with the traffic assignment model, and discusses issues with preparing input data for such a model system.