Disaggregate Treatment of Purpose, Time and Location in an Activity-based Regional Travel Forecasting Model
J L Bowman, Massachusetts Institute of Technology, US; M Bradley, US
This paper presents an activity-based regional travel forecasting model under development in Sacramento, California. Emphasis is given to practical issues of using a high degree of disaggregation in a large scale regional planning model system.
Incorporating an activity-based demand model with disaggregate treatment of activity purpose, time of day and location into a regional travel forecasting model system
John L. Bowman, Ph. D., Research Affiliate, Massachusetts Institute of Technology, 5 Beals Street Apt. 3, Brookline, MA 02446, USA, voice: +1-617-232-3478, email: John_L_Bowman@alum.mit.edu, website: http://JBowman.net
Mark A Bradley, 524 Arroyo Ave., Santa Barbara, CA 93109, USA. +1-805-564-3908, email@example.com
This paper presents a regional travel forecasting model system under development in 2005 for the Sacramento, California, Council of Governments. The system includes an integrated econometric activity-based demand microsimulation model with a highly disaggregate treatment of the purpose, time of day and location dimensions of the modeled outcomes. It is expected that, at the time of ETC 2005, the model system will be fully operational, nearing completion of calibration, and nearly ready for use in the regional transportation planning process and air quality analysis.
Recent planning efforts in the region focused attention on the importance of development patterns at the neighborhood scale. Planning tools currently in use for scenario analysis generate detailed descriptions of development scenarios, providing detailed attributes for each parcel in the region. It is desired to accurately predict in the travel forecasting models the travel impacts of alternative neighborhood scale development patterns, including the effects of things such as increased development density, mixed use development, improved walkability, and convenient transit access, as captured by the current scenario planning tools.
To help achieve this objective, the model system under development 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 eight specific purposes, and with a particular property parcel on which it occurs. The beginning and ending times of all activity and travel episodes are identified within a specific hour of the day.
The paper describes the model system design, estimation results, preliminary sensitivity analysis, and the status of model calibration. Emphasis is placed on the techniques employed for effectively disaggregating the treatment of purpose, time and space. The techniques are defended conceptually, and a special emphasis is given to the practical issues associated with using such a high degree of disaggregation in a large scale regional planning model system with equilibration of demand and network models.
Association for European Transport