The 2014 AMBAG Regional Travel Demand Model (RTDM) is an entirely new travel demand model estimated and calibrated to 2010 conditions using data from the 2010 California Household Travel Survey (CHTS), Census, employment, and traffic data from that same year. The model utilizes innovative techniques to capture travel behavior at a more individual-based level and incorporates disaggregate level data into some of the modeling stages. The primary reasons for introducing more disaggregate level data into the model was to assist in addressing elements of SB 375, and to pave the way for a possible transition to a tour-based modeling approach in the future. This updated model is a traditional four-step trip-based approach, and as such includes models for Trip Generation, Trip Distribution, Mode Choice, and Trip Assignment. Specific differences compared with traditional approaches include a population synthesis to drive the trip generation socioeconomic variables, calculation of the 4D variables (Density, Diversity, Design, and Destinations) using GIS techniques to support inputs to various model stages, the use of person-based trip rates, destination choice model for the trip distribution, and a mode choice component designed and estimated entirely from the survey.

The new model represents a significant improvement in functionality to the previous RTDM. The updated AMBAG RTDM has implemented most of the short-term and medium-term model improvement recommendations from the 2011 Travel Model Improvement Program (TMIP) peer review. A peer review of the updated RTDM took place in August of 2013. The model was used to develop AMBAG’s 2014 Metropolitan Transportation Plan (MTP) and Sustainable Communities Strategy (SCS).

Modeling Programs