BTPO uses TransCAD Transportation Planning software as the regional travel demand forecasting model. BTPO starting using TransCAD in 1992 and have developed many updates to the model. The draft 2015 model is based on the 2012 model which used 2010 Census data along with a household survey to help calibrate the model. The assumptions used in the 2015 model are based on the 2012 report. The 2015 Travel Demand Model Documentation provides a complete review of the validation and calibration process used in the travel demand model.
The BTPO travel demand model is a traditional model but the mode split step is not based on modeled data. The mode choice model using the 2010 household survey to determine the model split by the trip purpose to one of eight districts. Mode split adjusted the trips generation in each district and TAZ by the estimated mode split.
The travel demand models try to reproduce the traffic conditions in a given area based on the road network, population data, employment data, and information on driving characters of that populations. Travel demand models once calibrated and validated can use future road networks, population, and employment data to predict the travel on a specific roadway or the entire network. The BTPO Travel Demand Model included all public roads but only the collectors and arterial are used to model specific street segments. The local streets and special segments called centroid connectors are used to help estimate the regional Vehicle Miles Traveled (VMT).